‘I got AstraZeneca for my first dose. Which should I get for my second?’ A COVID vaccination guide

Download decision guide here

Why are we talking about this?

If you had AstraZeneca for dose 1, you now have a choice. You can get AstraZeneca for dose 2 or you can get a dose of Moderna or Pfizer instead. Moderna and Pfizer are mRNA vaccines and are very similar. AstraZeneca is from another group of vaccines called viral vector vaccines.

For this guide, we are sharing expert advice from the National Advisory Committee on Immunization (NACI), the Public Health Agency of Canada and Health Canada. You can feel confident that you have the most up-to-date science-based information to make your decision.

Content by Kelly Grindrod, PharmD; Noah Ivers, MD; Samira Jeimy, MD; Rosemary Killeen, BScPhm; Tara Kiran, MD; Kate Miller, MD; Menaka Pai, MD; Vivan Smith, PhD; Sabina Vohra-Miller, MSc; Kristen Watt, BScPhm; Holly Witteman, PhD; Samantha Yammine, PhD. Design by Adrian Poon, BA.

  1. Protection after two doses

The most important decision is to get a second dose. Dose 2 will give you stronger and longer lasting protection. Two doses of AstraZeneca are very effective at preventing serious illness from the original COVID-19 and early variants. Early studies show that people also generate a very good immune response (measured by cells in their blood) when Moderna or Pfizer are used after AstraZeneca. We have used different vaccines for boosters in the past for other viruses like hepatitis A, influenza and polio. It is safe and is not linked with any long-term side effects. This strategy is effective and suggests that a second dose of Moderna or Pfizer should be at least as protective as two doses of AstraZeneca.

  1. Protection against new variants

The Delta variant first discovered in India is spreading quickly in Canada. Two vaccine doses protect you against Delta much better than one dose. Two doses of Moderna or Pfizer appear to offer more protection against symptomatic infection from Delta than two doses of AstraZeneca. If you had AstraZeneca for dose 1, we don’t know yet if getting Moderna or Pfizer for dose 2 will give you better protection from Delta or future variants.

  1. Risk of blood clots

AstraZeneca has been linked with a very rare but serious blood clotting disease called Vaccine Induced Thrombotic Thrombocytopenia, or VITT. VITT can be fatal. According to reports from several countries including Canada, there are about 17 cases of VITT for every million people given dose 1 of AstraZeneca. For dose 2, the risk of VITT is estimated to be 2 for every million vaccinated. These estimates may change as more people around the world have dose 2 and we learn more. The Moderna and Pfizer vaccines do not cause VITT.

  1. Side effects

It is common to have side effects like a sore arm, fatigue, headache, fever or sore muscles after AstraZeneca, Moderna or Pfizer. This is a sign your immune system is working to build protection.

We don’t know yet if you will have fewer or more side effects if you choose Moderna, Pfizer or AstraZeneca for dose 2.

  1. Availability

Canada is receiving much more Moderna and Pfizer vaccine than AstraZeneca. This is expected to continue all summer. Much of the global supply of AstraZeneca is being used elsewhere in the world. It may be easier and faster to get Moderna or Pfizer for dose 2.

Understanding the research on using two COVID-19 vaccine types.

What is known about having AstraZeneca for dose 1 and dose 2?

The United Kingdom (U.K.) has one of the largest vaccine programs in the world. Real-world data from Public Health England shows that two doses of AstraZeneca are 66 per cent effective in protecting people from a mild, moderate or severe COVID-19 infection. This means they lower a person’s chances of getting COVID-19 by 66 per cent. Two doses of Moderna and Pfizer are 93 per cent effective.

Researchers at the University of Edinburgh in Scotland also found that dose 1 of AstraZeneca or Pfizer is 90 per cent effective at preventing people from getting sick enough that they need to go to the hospital. Another study from the U.K. of 150,000 people over age 70 found that 1 dose of AstraZeneca or Pfizer was 80 per cent effective at preventing people from needing hospital care.

More recently, the Delta variant has spread rapidly in the U.K. It is spreading rapidly in Canada, too. A new study from the U.K. suggests one dose of AstraZeneca is 33 per cent effective against symptomatic infection from the Delta variant. Two doses are 60 per cent effective. The same study showed one dose of Pfizer is 33 per cent effective and two doses of Pfizer are 88 per cent effective against symptomatic infection from the Delta variant. This means that to protect yourself from the Delta variant, it is very important to get two doses.

What is known about the effectiveness of having AstraZeneca for dose 1 and Moderna or Pfizer for dose 2?

On June 1, the National Advisory Committee on Immunization (NACI) advised that Canadians who had AstraZeneca for dose 1 have the option of Moderna or Pfizer for dose 2.

NACI’s advice was partly based on early results from a CombiVacS study in Spain. CombiVacS enrolled 663 people who had AstraZeneca for dose 1. They gave two-thirds of people Pfizer for dose 2, and a control group of 232 people have not received a second dose yet. Early results found that a dose 2 using Pfizer increased the antibodies people had after 1 dose of AstraZeneca. Many scientists believe this is a sign the combination of AstraZeneca and Pfizer (or Moderna) likely works well.

Recently, a study in Germany enrolled 340 health-care workers who had AstraZeneca or Pfizer for dose 1 and gave them Pfizer for dose 2. Early results show that the AstraZeneca-Pfizer combination gives a similar immune response against many of the variants compared to 2 doses of Pfizer. These results would probably be the same or similar if dose 2 had been Moderna.

There is a larger study in the U.K. called Com-COV that enrolled 800 people and is researching the benefits and risks of combining AstraZeneca and Pfizer. The results will be reported soon.

What is known about the safety of having Moderna or Pfizer for dose 2?

Scientific studies are key to making sure that vaccines are safe and effective. Real world experience is also important. Many countries around the world are mixing vaccinations with positive effects like lower rates of COVID-19 and fewer people needing hospital care. So far, their experiences do not suggest any more risk from choosing a different vaccine for dose 2.

You may have more, the same or fewer short-term side effects from a dose 2 of Moderna or Pfizer compared to a dose 1 of AstraZeneca. The Com-COV study showed that people who had AstraZeneca followed by Pfizer four weeks later had more side effects than those who had 2 doses of AstraZeneca. Side effects lasted for one-two days and included tiredness, fever and achy muscles. Side effects resolved with rest and over-the-counter medicines. No one needed hospital care. The Spanish and German studies gave the second dose 8-12 weeks later. The side effects were similar for people who got AstraZeneca for dose 1 and AstraZeneca or Pfizer for dose 2.

Vaccines help train your immune system to recognize and fight the virus that causes COVID-19. As the immune system starts making antibodies from the vaccine, it is normal to have side effects like the ones reported in these studies. It is like being sore after a good workout – your immune system is learning a new exercise. These expected side effects may last one to three days.

Every person’s immune system is different. Some people have stronger side effects. Others have milder side effects and some people have no side effects at all. It is important to know that these side effects mean the vaccine is working as it should.

Why is it OK to ‘mix and match’ vaccine brands?

“Mixing and matching” means you use one brand or vaccine type for dose 1 and a different vaccine brand or type for dose 2. There is evidence for mixing and matching vaccine brands from scientific studies and real-world experience. It can be done when there are problems with supply, when a rare but serious side effect is identified or to get a stronger immune response. It is generally safe and effective.

Similar to AstraZeneca, a rare but serious side effect was identified with the oral polio vaccine in the 1990s. Canadians who needed four doses were switched to an injectable polio vaccine. This worked well and was safe. Hepatitis A also uses a 2-dose vaccine. Sometimes, when a brand is used for dose 1 but not available for dose 2, another brand will be used.

Other countries are using a mix-and-match strategy, too. For example, in Norway people who received AstraZeneca for dose 1 will be given Moderna or Pfizer for dose 2.

When is the best time to get dose 2?

The original AstraZeneca, Moderna and Pfizer clinical trials separated dose 1 and dose 2 by three-four weeks. That interval was chosen to finish the trials as fast as possible and end the pandemic.

Newer research from the AstraZeneca trials showed that people had better protection if dose 2 was given closer to 12 weeks. Previous research on Pfizer found that a delayed dose of eight weeks may also offer better protection. This is also true of many other vaccines. In part, that’s why NACI advised Canada to delay the second dose to 16 weeks for all COVID-19 vaccines. A delayed dose 2 would allow more Canadians to get some protection quickly while still getting the benefit from dose 2.

Now that the Delta variant is spreading, it may be better to get full protection faster. Having an earlier second dose will result in strong protection much sooner, even if waiting a few weeks longer would mean slightly stronger protection.

The vaccine you get may depend on where or how fast you want to get dose 2. For example, if you work in a crowded space or live in a COVID-19 “hot-spot,” you might want to get dose 2 as soon as possible. If you work from home, are relatively isolated and don’t have any personal risk factors (for example, a chronic disease), you may feel you can wait.

If I get Moderna or Pfizer, will I need more than two doses?

The NACI guidance for Canada says that you are “fully immunized” once you have dose 1 of AstraZeneca and dose 2 of AstraZeneca, Moderna or Pfizer. Two doses of Moderna or Pfizer are not needed if you already had dose 1 of AstraZeneca. This approach is being used in other countries as well.

Many countries have travel and activity restrictions based on vaccination status, often referred to as a “vaccine passport.” Each country will have different guidelines but many of them say that two doses of any approved vaccine is considered fully immunized.

Developed by Kelly Grindrod, BScPharm, PharmD, MSc; School of Pharmacy, University of Waterloo. Adrian Poon, BA; University of Waterloo. Andrea Chittle, MD; Department of Family Medicine, McMaster University. Noah Ivers, MD, PhD; Women’s College Hospital-University of Toronto. Kate Miller, MD; Department of Family Medicine, McMaster University. Sabina Vohra-Miller, MSc; Unambiguous Science. Kristen Watt, BScPhm, RPh. Holly Witteman, PhD; Department of Family & Emergency Medicine, Université Laval.

Other Things to Consider

The most important thing is to get dose 2. It can be AstraZeneca, Moderna or Pfizer. As you make your choice, think about what is most important to you:

How did I feel after dose 1 of AstraZeneca?

  • Many people were worried about the risk of severe blood clots and do not want to worry again.
  • Many people had side effects such as a sore arm, fatigue, headache, body aches and chills.
  • It is not known if there will be more, the same or fewer side effects if you get a dose 2 of Moderna or Pfizer.
  • You may want to plan for an easy day after dose 2 with any COVID-19 vaccine.

How long will I have to wait for dose 2?

  • Canada is getting a large supply of Pfizer and Moderna right now.
  • Most people should be able to get a dose 2 of a vaccine 12 weeks after dose 1, including AstraZeneca, Moderna or Pfizer.
  • Adults aged 70 and over may be able to get a dose 2 of AstraZeneca, Moderna or Pfizer now.
  • Adults aged 40-69 may be able to get AstraZeneca now or may have to wait a few weeks to get Moderna or Pfizer.

How do I decide between Moderna and Pfizer?

  • Moderna and Pfizer are essentially the same vaccine.
  • Both the Moderna and Pfizer vaccines are mRNA (messenger RNA) vaccines.
  • Both Moderna and Pfizer provide similar protection against COVID-19.
  • Both Moderna and Pfizer have similar side effects.
  • Pfizer requires colder freezers and is more difficult to use so it is often given at large vaccine centres and busy pharmacies.
  • Moderna is easier to use and may be available at primary care clinics and smaller or rural pharmacies.
  • Get the vaccine that is easiest or fastest for you.

Being fully vaccinated offers great immune protection from COVID-19, including all the variants studied so far. For 2-dose vaccines like AstraZeneca, Moderna and Pfizer, “fully vaccinated” means getting 2 doses, even if dose 2 is a different brand than dose 1. The important thing to remember is that a second dose with AstraZeneca, Pfizer or Moderna is better than no second dose at all.

If you have questions or need to discuss further, please contact your doctor, nurse practitioner, or pharmacist before you book your vaccine appointment.


Kate Miller, MD; Department of Family Medicine, McMaster University.

Kelly Grindrod, BScPharm, PharmD, MSc; School of Pharmacy, University of Waterloo.

Noah Ivers, MD, PhD; Women’s College Hospital-University of Toronto.

Samira Jeimy, MD, PhD, FRCPC; Division of Clinical Immunology and Allergy, Department of Medicine, Western University.

Tara Kiran, MD, MSc, CCFP, FCFP; Department of Family and Community Medicine, St. Michael’s Hospital, University of Toronto.

Menaka Pai, MSc, MD, FRCPC; Department of Medicine, McMaster University.

Adrian Poon, BA; University of Waterloo.

Vivian Smith, PhD.

Sabina Vohra-Miller, MSc; Unambiguous Science.

Kristen Watt, BScPhm, RPh.

Holly Witteman, PhD; Department of Family & Emergency Medicine, Université Laval.

Samantha Yammine, PhD; Science Sam Media.

The comments section is closed.

  • Rigen Ian Carvajal says:

    Hello and good day,
    I have been vaccinated last May 19 2021 by the AstraZeneca and and my 2 ND dose was on August 5 2021 i was vaccinated again by Johnson’s & Johnson’s. Then it is ok to take another booster shoot from Pfizer or Moderna .
    Your advice is very helpful to me of what vaccine to be my next choice.
    Thanks and more power

  • Maria Celia R. Nalasa says:

    i just want to know if it is to get again a vaccine moderna even if im already have a ist dose of astrazenica that was done 5 mos. ago? can i have my vaccine again ist dose and 2nd dose of moderna? please do help thank you.

  • Norah says:

    If you are fully vaccinated with 2 Astra Zeneca shots is it safe to get revaccinated with 2 Pfizer shots? If so how long should you wait?

  • Amit says:

    A person outside India, who has received first dose of AstraZeneca’s vaccine, whether he can take second dose of COVISHIELDTM in India?

  • PRANIL CHAND says:

    In my country australia mix and match of covid 19 vaccine is not permitted. I had my first dose of aztrazeneca and then second dose of pfizer 10 weeks later. I am worried if my immunity is going to be working against covid 19 as I am only one of few individual’s with mix an match here while the rest of the country is going for same dose. I am thinking if I need pfizer as third jab to complete my programme as it says you need two dose of the same vaccine to have full immunity.

  • Saleh alyazedi says:

    I take the first dose of AstraZeneca vaccine

    But in our country there was no any AstraZeneca for second dose

    But there is Johnson and Johnson vaccine

    Can i take it as second dose

    Please answer

  • Jeff Puchalski says:

    Anyone have an answer for this great question above as i would like to ask the same. how long should you wait after getting AZ 1st dose and then Pfizer/Moderna for your second jab? It seems unclear on the best wait time. I am in Vietnam so my windows are small and need to plan ahead as best as possible. thanks for any help!

  • Krishna says:

    Can I take Moderna vaccine after getting fully vaccinated with Covi Shield (Astra Zeneca) in the month of April, 2021?

  • Kerry Dunn says:

    As AZ is a different type of vaccine than Moderna/Pfizer, is there a minimum time one should wait before getting a jab of either of the latter ?
    For example, someone gets an AZ vaccination and wants a Moderna/Pfizer jab as their second dose. As the two provide protection in different ways, would getting the 2nd shot sooner be better than waiting 8-12 weeks ?

    My understanding is that one increases anti-bodies in the system and the other increases T cells. Assuming one had no noticeable side effects from their first vaccination, would getting a dose of another kind within 2 weeks of the first be an issue ?

    • Jeff Puchalski says:

      Anyone have an answer for this great question above as i would like to ask the same. how long should you wait after getting AZ 1st dose and then Pfizer/Moderna for your second jab? It seems unclear on the best wait time. I am in Vietnam so my windows are small and need to plan ahead as best as possible. thanks for any help!

    • A. Khan says:

      My daughter has 1st dose of Moderna and 2nd dose of Astra Zenica. Is it ok? Are there any clinical trials of this mix and match approach?

  • Daniel Hochhausen says:

    If a person has had 2 doses of Astrazeneca can they also get 2 doses of pfizer ? The reason being that some cruise companies will not accept Astrazeneca.

  • Vishwanat Mamadapur says:

    I can take first dose is astra zanica and second dose covisild

  • Vicha siri says:

    I received AZ as first dose on April 6 , Moderna as Second dose on June 16 . Is it ok to receive Another shot of Moderna now . I want to travel to Thailand but they only certify 2doses of AZ or 2doses of Moderna. ( not mix match)

    • Daniel says:

      It’s not a good time to visit Thailand. Only 6% of the population have been vaccinated with a first dose and very few with 2 doses. Travel within the country is restricted and there is a curfew in the cities. Shops and markets have reduced opening hours. I live in Chanthaburi province.

  • Michelle Cossalter says:

    I ask a simple question. Can i have the second astrazenica jab after 8 weeks as stated on the news recently. I have not been able to get an appointment prior to 12 weeks in my local area. Is the publicity correct or just political spin. I am trying to help protect the community and myself. But am finding it all too difficult to get a straight answer.

  • Rasha says:

    Is the second dose of astrazeneca has the same component of the first dose

  • Elie says:

    i got the first dose of Astrazenica 11 days ago. is it enough to have immunity ?

  • dawa says:

    I am kidney transplant patients, so which vaccine prefer for my second dose.

  • Nelly lapa-an says:

    Hello i want to ask if i can get 2 doses of pfizer after getting 1st dose of astrazeneca? Im 28 yrs old, and i take the 1st dose of AZ last march 19

  • Dr. Soleman Mozammel says:

    I took two doses of Sino Pharm and one dose of pfizer booster in Bahrain. So, if I take one dose of pfizer vaccine now, am I considered to be full vaccinated in Canada.

  • Quazi s hossain says:

    Before 3 months took one dose Astra Zeneca but I wants to take others 2 doses may be Pfizer or moderne full courses

  • Sarah smith says:

    My father 75 yrs got covid shield as a first dose, can he take johnson vaccine as a second dose?

  • Joseph Sunil says:

    I have taken Pfizer 1st dose, which vaccine should I take as second dose? Can I take AstraZeneca as second doze after Pfizer first dose?

  • ATIQ UR RAHMAN says:

    I got first dosage of Astrazenica Oxford covid-19 vaccine.
    Can i shot second dosage of moderna or pfizer now?

  • AnA guldemond says:

    Can I travel to Europe with dose 1 Astra @ dose 2 moderna?

  • Ray says:

    My mother got the first dose of Astrazenka vaccine outside the United States, can she get the Pfizer vaccine?

  • B says:

    I think Yes because it’s still the same kind of vaccine and the same ways to produce vaccines.

    • Ray says:

      July 3, 2021 at 5:24 pm
      My mother got the first dose of Astrazeneka vaccine outside the United States, can she get the Pfizer vaccine?

      • ATIQ UR RAHMAN says:

        I got first dosage of Astrazenica Oxford covid-19 vaccine.
        Can i shot second dosage of moderna or pfizer now?

  • B says:

    My cousin is in the same case and he decides to get an mRNA vaccine soon.

  • B says:

    I’m from Thailand, which have many problems with Vaccine management.
    I wonder if soon I will get my first dose of AZ then wait for 2 months to get Moderna.
    I have searched a lot but still cannot figure out
    “Is the first and the second dose of MODERNA vaccine are the same or not?”
    If not, which dose should I get the first or second dose of Moderna?

    Ps. I plan to get AZ first then followed by 2 doses of Moderna (If it possible).


    • Sherry says:

      If you get the AZ first, then you will only need 1 dose of Moderna, not 2. That is how I am doing it. My first dose was AZ, but that is no longer available in my area, because of the serious outbreak in India. My pharmacist called to inform me that the Moderna is what was sent, so that will be my second and final dose.

  • RT says:

    I don’t condone the tone of @Dave Whitehead’s comments. The underlying frustration is clear. The authors could have done a much better job of qualifying the evidence on which their recommendations are based.

  • Ken Cook says:

    I’m not interested in mixing vaccines. I just applied online and it said I’d either be getting the Pfizer or moderna vaccine. I was told I wouldn’t know until I arrive at the clinic at my scheduled time. If it’s not the same I’ll have to cancel. Why cant you let me know ahead of time so I’m not wasting your time and I’m not wasting your time.?

  • Ian Davis says:

    I received my second shot (Pfizer) 72 days after my AZ. I had no apparent side effects whatsoever from the AZ. With the Pfizer, I had a slightly sore arm near the injection site, low grade muscle pain in the arm and shoulder, and a bit of fatigue for 3 or 4 days. Not an inconvenience at all.

    As it turns out, I did get the mRNA vaccine I wanted for my second shot but I would have taken the AZ if offered first. My goal was complete vaccination ASAP. The numbers may look better with a mix but won’t it take a year or more to get enough data to make a definitive recommendation?

    Side note: The only people with “blood on their hands” are the anti-vaxxers, anti-maskers, and their trolls.

  • Patricia Nitschke says:

    Great article I wish I had seen it before I had my second vaccination. If I had I would have had the Pfizer or moderna rather than the 2 AZ.

  • Stevie Brinkerhoff says:

    My daughter and her partner received both doses of Astra Zeneca in India, with the second dose in May. They are coming to the US in August. Would it be worthwhile to get a 3rd dose of the Pfizer or Moderna while here to increase the efficacy of the vaccine? It’s too soon for a booster I know.

    • RT says:

      Are these recommendations evidence-based?
      What evidence exists on the efficacy of mixing vaccines? How does the quality of that evidence compare to the quality of evidence used get the vaccines approved by Health Canada?
      Why is the side effects summary in the article so markedly different than summarized in the Health Canada-approved product monographs for each vaccine?

  • Natividad Ramnarinesingh says:

    I received my 2nd dose of AstraZeneca yesterday.Today in the news it was announced that it is best to get moderna for the 2nd dose.In these case should we be given another dose of moderna ?
    When the border opens between USA and Canada , since I received both AstraZeneca am I allowed to cross the border ?

  • Syed Naveed Peerzada says:

    Hi . I received the first dose of AstraZeneca vaccine, followed up by Pfizer vaccine as the second dose. Just want to know, what if I get the Pfizer vaccine again as the third dose. Will there be some severe / serious side effects . Any studies available about such patients ? If so , kindly let me know thanks.

  • Margaret Wright says:

    The best, most straightforward, informative article I’ve read so far

  • Simon says:

    Great summary! Complete and giving clear directions base on all possible cases! Thanks, I will sleep better tonight and wake up early tomorrow trying to get an appointment for my second dose! :)

  • Kiran Srivastava says:

    I am 65 yrs female with RA and immunocompromised patient.I received a first shot of Astra Zeneca vaccine. Can I be given another shot of vaccine from Pfizer for a better immunity.


    I took my first vaccine astrazeneca, should i take the same one for my second jab or not, what do you suggest.

  • Rajeev Shrestha says:

    I got vaccinated Astra zeneca as 1st dose on 14 Jun 2021 at kabul (Afghanistan). On 01 Jul 2021 I shall be proceeding on 30 days leave to India. Can I go for Covishield vaccine as second dose in india. Pliz suggest.

  • Madhumita says:

    If anybody takes first dose of covaxin from Bharat Biotech and now he has an option from Astrazenace vaccine only, when he can take first dose?

  • Alison Tanner says:

    Thank you – my daughter in law has had Moderna for her first vaccine whilst working abroad., are there any studies to show what happens if she has Pfizer for her second as in GB Pfizer seems to be easier to access?

  • April says:

    This was an amazing and very informative site for those of us with the Astra 1st dose.

    Thank you so much!

  • Diane F Vicente says:

    I know that efficacy rate for Astrazeneca after both doses is 70%. What is the efficacy of Astrazeneca first dose and Pfizer 2nd dose?

  • Phil Massad says:

    Canadians were advised by NACI to take the first shot offered. Then NACI said the Pfizer and Moderna were the “preferred vaccine” after Canadians received AstraZeneca, loss of confidence in AstraZeneca and stress to Canadians who received the AstraZeneca. The NACI has stopped giving AstraZeneca as a first dose, so there is a loss of confidence in AstraZeneca and more stress. After reading the above article, Canadians now suspect there isn’t enough mRNA to be administered in a timely fashion to stop the Delta variant and NACI wants the AstraZeneca recipients to get AstraZeneca as a second dose, so the Pfizer and Moderna goes to those who received them on their fist dose, in a timely manner. There is no AstraZeneca vaccine in Ottawa so again Canadians who received AstraZeneca who want to receive the 2nd shot of astraZeneca are out in the cold. It is most likely AstraZeneca at some point will be unavailable and Canadians who received AstraZeneca and will have to, at some point, cross over to mRNA.
    Question, How can Canadians who received the AstraZeneca vaccine believe anything the NACI writes. Canadians are best served by researching information from international research rather than those appointed to the NACI.

    • Sarah says:

      I completely agree. I am so frustrated and have lost all support of Canada’s immunization guidance. I am very science-based, but am beyond furious the way those of us who got AZ have been treated.

      • Rebecca says:

        Yes, me too!! It’s unbelievable the messaging they told, then changing on whatever whim to suit their agenda. It feels like we were test bodies to them

    • Rebecca says:

      Yes, thanks for stating exactly what I’ve been feeling too. It’s impossible to find any information or even answers to these concerns. And who’s to say tomorrow won’t have more emerging evidence that states something different? How are we supposed to trust?

    • Bill says:

      I agree and also had AZ based on previous advice from NACI. Messaging has been inconsistent and contradictory. This has resulted not only in a loss of confidence in the medical advice but also stressed and pissed off first recipients of AZ who feel that they were sold on a lie; i.e. the “best vaccine is the first one offered to you” only to be told later that the “emerging science” now suggests that mRNA are not only safer, but more effective as well.

  • Dr Hamzeh Malkawi says:

    Hi SE
    Thank you very much for the information you wrote about

  • Zenon Mandziuk says:

    Clearly and comprehensibly communicated. A pleasure to read unambiguous science.

  • Qudratullah Soofizada says:

    I have a question if anybody helped me. So I have got my first dose of vaccine in Italy from Astrazeneca company which was produced by Oxfort. Now it is time that I should get the second dose, as currently I am in Afghanistan and the available vaccine is AstraZeneca which produced by Indians.
    My question is that, can I get my second dose of vaccine from AstraZeneca Covisheild which is produced by Indian?

  • Felix Parsons says:

    This is a very well written article.

  • SE says:

    I just want to be clear these are NOT empirical results. I have been following this since the beginning and I am disgusted. Pfizer started work on this vaccine weeks before Wuhan even announced a problem so their “vaccine” is pre any variant that anyone should and is worried about. They are a technology that prior to the pandemic the health authorities said was years away from being allowed to even test on humans and now people are just taking it.

    If you go to Astra Zeneca site they are very clear about all their studies and give information to where all their information comes from. They have been rail roaded by Pfizer investors. Did you know the chance of you having a clot from Astra Zeneca is less than a fraction of a percentage. It’s from a genetic disorder and to the person who’s family had brain aneurysms that’s not it. You had psychosomatic symptoms very very likely. If it was the clot they would have caught it and there’s a very easy test for it. But not to make it more scary you can get the exact same clots from all the other vaccines and people do. Funny the news isn’t talking about that non stop right. Its actually just a small percentage less. So if Astra Zeneca gets 17 in a million in Canada than Pfizer would get 15 or 12 in a million. And same with all the others. You can find this fact in the medical data. Plus covid is 17 times more likely to have blood clots and it’s not from a genetic disorder almost no one has. With covid the blood clots are a symptom of the illness so getting vaccinated is just safer. Also to the person who got Astra Zeneca already you don’t have it. The news is causing this in people. Astra Zeneca is actually the best vaccine as far as protection to the virus goes. They are the most open and you can track their studies easily.

    Now Pfizer, go to their site. You can’t find a single thing their easily that speaks to openness. Wanna see an actual study. They send you to an out side website where it take knowledge of studies to find anything. If you don’t understand how studies work too bad for you. I found dozens of studies that they have been claiming as finished that haven’t even started. I found those that are done where they used extremely biased standards for everything. The biggest one everyone is quoting right now. That it’s safe to use Pfizer after Astra Zeneca. They haven’t started that study. The study claimed they would have started it by now. But they did not. It just sits there in started. They are making claims all over because a quick glance shows they did apply for that study. That’s fraud. So I went back and looked. They have been doing that the whole time. The data that they are 99% effective which I already knew was a lie comes from a study which they take the data they get minus 1 from the results, flip the results and times them by 100. My husband and I were floored. By reading this study; which they did do; they were ZERO percent effective but they just made themselves 99% effective by fraud. They put out a chart that a child could make and the world(never me I have hated them day one because it’s clear what they are doing) kisses butt. I find the extent everyone lies for them sick. Canada says the uk has studies showing Pfizer should be taken after Astra Zeneca to stop the delta variant. The uk is ordering in as much Astra Zeneca so they can to revaccinate people who took Pfizer to stop the delta variant. They are NOT saying take Pfizer. You will notice though every single one of these say it only works if you take Astra Zeneca first. This is because Pfizer is garbage and people who took two Pfizer shots are getting sick and have been the whole time. They need another company to blame.

    Pfizer has drastic side effects and has killed a LOT more people than Astra Zeneca. In fact if you look now that the knowledge of what to watch for is out, the clot deaths of Astra Zeneca is near zero world wide and there are not really other serious side effects. But pfizer has a book of side effects and hundreds of people per hundred thousand that have serious effects. The deaths for Canada are continuing being blamed on weak people so it doesn’t go to Pfizer which is illegal but nothing I can do. World wide it’s hundreds per million which is more than Astra Zeneca but the news focused on less than a percent which shows corruption.

    You want truth there it is. Which vaccine is safest Astra Zeneca. If any vaccine claims when they have had only months to work on it and it’s a technology previously not allowed to even be used on humans to be 99% effect something is wrong. I took pictures of their actual study in case they try to delete it or change it. All of which are illegal too. Not that they seem to care I’ve seen a lot disappear since the beginning but I’m taking the proof now. The study was written like non sense. They made it so hard to read and make sense of. I believe to attempt to hide the fraud. It took us a bit to work out wtf was happening. All there other studies were way to read even when clearly committing some form of fraud. All I’m saying is the government is filled with people. They are not perfect and they are subject to being tricked or to committing trickery themselves. This is your health. Pfizer/moderna is dangerous. I’m a very sick but highly educated individual who has been following this since day one and I’ve been shocked at the lies and the dangerous medicine(if you could call it that) they are putting in people. I’m afraid of vaccines myself as I’ve had reactions to everyone I’ve ever had and I have to genetic illnesses. One is rare enough that one in 20 million have it. The other one I’m the only person in the world with. I know how bad the Canadian health system is. I really do. My own doctor and a few specialists did not find my illnesses I found them by insisting I get genetic testing because of how sick I am and they were telling me to get over it. The doctors here are corrupt often and lazy when not corrupt. Anyone who calls me a Karen I have actual proof of this. I’m dying and I don’t have to be. I sit at home everyday getting worse by the day because the doctors don’t want the work. So if you doubt what I say about the vaccines I’d say I’m sorry you don’t care enough about your health and those around you to do the work either. Protect yourselves. Watch some videos of real people infected with covid. Not news videos. Young people. So you know what the real consequences are. This is no joke. The effects are life long.

    I’d lastly like to say I don’t go on Facebook. I haven’t been in over a decade. I refuse to use Wikipedia as it’s not an educational site nor is it respected or respectable. I don’t get this stuff from news sites although I do have glances at the news daily to see what they are telling the people. It’s gotten bad and very biased so I’m careful. I go to scientific sites, educational sites. I check the sites of all the vaccines themselves and see what they are offering. It’s very clear by how shady Pfizer has acted the entire time and how open the Astra Zeneca site has been what a difference that is. I go to government sites and check data but after time the data on the Canadian sites did not match up with what they sent the WHO which is very telling. They were trying to scare the people with the numbers they were printing on the government sites as well as buff up Pfizer because they sent thousands of serious reactions to world health but where is that? They were telling people Astra Zeneca caused deaths and sooo many blood clots. Meantime it was 17 blood clots per million and Pfizer is causing people to die. My husband wants me to stop as people are to indoctrinated and I’ve been going for a while. So please think. Pfizer is 1% effective I have the data and you can too. Heck the news even shows this now it’s why they are panicking and wanting their vaccine after Astra Zeneca. You don’t see it the other way around do you?

    • Elaine says:

      You recommend astra have astra first shot my sister really sick after 2 nd

    • Bradley Morgan says:

      Are you nuts?

    • Nat says:

      I 100% believe in what you are saying. I’ve been telling my family that I found it so odd that AZ was getting such a bad wrap. I’m not a conspiracy theorist however at the end of the day it’s all about money. Its a bit too convenient that AZ a drug that is cheaper and much easier to transport is getting so much bad press and no one is putting pressure on the high cost of Pfizer which is harder to distribute and store.

      This whole process has been completely frustrating. I’m here contemplating my next move of whether I take AZ as my 2nd dose and its hard. No matter what I do at this point until the FDA actually approves AZ even if they don’t use it in the US I will still be at a disadvantage since mixing doses is still another thing that will require acceptance within the USA seeing that no decision seems to be concrete until they say it is. Crappy situation all around.

    • Deb says:

      I think people that definitively state hat people have died from the vaccine should post the reference material where they get these “facts”. Just throwing that out there as fact is an irresponsible statement.

  • JM says:

    When you say 2nd dose of Pfizer/Moderna, you mean the booster right? Got a bit confused if I should take the primer or booster for my 2nd dose. God bless.

    • Annie says:

      The terms primer and booster to refer to first and second shots are just names, there is no difference in the content of a first (“primer”) or second (“booster”) mRNA shot. The dosage is identical for both shots.

  • May says:

    I had some reactions to Astra Zeneca vaccine for the the 1st jab..had many of stroke symptoms and my father,mother and sisiter died due to brain Stoke.(so I was scared I would die and leave my children). So I’ve been advised by the emergency team to get the Pfizer one for the 2nd dose, and they told me to discuss my situation with my GP. I was struggling to get an appointment for the Pfizer vaccine and been sent back and forth between my GPpractice and 119.GP says you don’t need anything just go and have it and at vaccine centre or when I call 119 they asked me for a letter from my GP or my GP should book the appointment for me.I stayed in this loop for about 3 weeks and anybody can imagine what I’ve been through while I have already severe depression and anxiety.
    I went to the practice and asked to see the GP face to face to get my issue solved, they didn’t help.. the nurse told me you don’t need the Pfizer go and get the Astra Zeneca..I told her you are not in a position to decide for me I need to discuss this with a DOCTOR.. I had break down there crying and frustrated..the same nurse went to discuss with GP and they sent the receptionist to tell me he will book an appointment for me!!!
    From yesterday I don’t know how I’m keeping my life going on.. nobody deserves to be treated like this in this country or any place in the world.

    So it’s not easy to choose what vaccine to get.real life is different from blah blah

  • Joel says:

    While I appreciate the empirical results can add or change the science and resulting recommendations for COVID vaccinations but the changing recommendations from National Advisory Committee on Immunization (NACI) is frustrating for the citizens early to accept an AstraZeneca vaccination. Of disappointment, is with significant lot of vaccine expiring on May 31, NACI on Sunday May 30 extended expiry date until June 30, and I have not found where NACI providing the transparency to citizens taking AstraZeneca of some public disclosure of a written statement for the manufacturer of AstraZeneca that is is okay to do use expired vaccines or extend expiry dates. Are we left to assume or wonder was there a sniff test of the lot, observation no curds in the (milk of) vaccine or some science to actually support the decision to extend the expiry date or was it a arbitrary decision or political decision, some transparency would be appreciated such as the science behind the decision or actually consultation with the manufacturer. Then adding to citizens taking AstraZeneca frustration a couple of days later (June 1) seeming NACI says it is now ok to mix and match AstraZeneca with other vaccines but, don’t mix and match the other vaccines with other vaccines. While is get the AstraZeneca supply is short as it is not being shipped to Canada since May 23 (see Again NACI rapid decision that seems to be more political motivated than based on a lot of science (couple of hundred volunteers in Europe seems to be the evidence to mix and match). Maybe the Canadian citizen now volunteering to mix and match AstraZeneca will add to the evidence/data on mixing vaccines? But is does seem frustrating the advice provided by NACI is it ok to mix and match and then you are left to decide what to do…do I wait 12 weeks for the 2nd dose of AstraZeneca, or go for Moderna or go for Pfizer now, three choices for citizens taking AstraZeneca to make and no or little “real” (significant evidence) medical advice from NACI. I get it not significant AstraZeneca supply chain now, but maybe cut the choices down to two at most, citizens are not medical professionals, and with the NACI lack of transparency decision making or lack of clear direction to people (were not telling you what to do….you decide) this I think lack of transparency and simplifing the choices could tarnishes the rest of the medical profession. Being an Professional Engineer I think of the Engineering negligence which resulted in the Elliot Lake Mall Collapse and I hope we don’t have a parallel negligence in the rapid decision making on advise or lack of advise on what is the right thing to do, the extension of expiry dates of vaccines or leaving three choices on the table for non medical profession citizens that we now must make for our second dose all rolled out over the three days between May 30 to June 1. We all need to do our part and roll up the sleeve, but Jees Louise be clearer please! Personally, I think I’ll wait the 12 weeks from my April 12th first dose and hopefully there will be some not expired and extend AstraZeneca available in July. BTW, when negotiating its better to give the other party two choices, not three…three is just poor structuring how you negotiate.

    • SE says:

      I’m glad to see some smart citizens out there instead of just sheep. If you read my other response you are correct. The government is dining all this motivated by money and politics. The studies for the vaccines being mixed have not even started. I have them on my phone I took pictures. The worst part though is they are heavily biased. They won’t start till people have had all the vaccines already. Then they will give four hundred people vaccinated twice with the Astra Zeneca vaccine a Pfizer vaccine and see what happens. Duh I wonder. 400 people with either one Astra Zeneca already and one moderna Pfizer or fully vaccinated Johnson and Johnson and then 95 people who have not been vaccinated will get the Astra Zeneca and the Pfizer vaccine mix. They were supposed to test this on people who had previously tested positive for covid and been hospitalized for it or had the virus very seriously. The 95 people who will get the mix it is very specific must be healthy with no hospitalizations ever and conditions of any kind and must test negative for covid plus never have had it. Then the other 800 people can have tested positive for covid but must not have been hospitalized for it or have serious health conditions. So they are already lying and changing the study. If you read about the info for the break down of the study it claims they are using previously tested positive and tested positive and hospitalized people who are now vaccinated with a mix of vaccines. The truth is the only mix is Pfizer after something else first and 800 of them will have been vaccinated fully vaccinated for months before the one Pfizer shot. This study was to start in April of this year and end in 2023. It has not even started yet. So where do the claims come from that you can do this and it works? Also Pfizer has had non stop issues with people testing positive for covid after being fully vaccinated. The 99% effectiveness study they released came again from a study with the same type of trickery only worse this time. They were found to be less than 1% effective and flipped that finding to say 99%. That is fraud and no one even said anything. You are also correct in questioning Canada just changing the expiry dates on Astra Zeneca. A better way to deal with this would be to admit that they were using fear mongering with the blood clots and that Astra Zeneca is a great vaccine. Do they talk about the thousands of people having severe reactions to Pfizer? No. Interesting isn’t it.

      • John Stockton says:

        If you are an expert you should be willing to publish this under your own name and be accountable like the authors of this article. Otherwise you are a fraud and simply spinning conspiracy theories.

      • Joel says:

        SE be nice if you could provide a link to some of the data or the pictures you have on you phone.

        Had some difficulty understanding what you saying about the Pfizer efficacy being 1% that seems like “anti” vaccine if its only 1% efficacy

    • John Stockton says:

      Comparing this with the Elliot Lake Mall is apples and oranges. As a p.eng. you know that the ELM incident was clearly negligence in the face of evidence, and frankly laziness and cheapness of the owners. With Covid , there are many scientific studies ongoing. For sure exactitude may be lacking, but the number of eyes on this is unparalleled.

      • Joel says:

        Hey John, you’re right it’s a challenging comparison to make the ELM negligence to NACI who appear to be making it up as data comes in, but some of rapid changing messaging does test your confidence in what they dispense.

        It was late that night when I wrote that but gees I’m a little upset with how the whole AstraZeneca file handled and my frustration were in the words.

        Probably a better comparison for some of us trusting advise and getting (AstraZeneca) the taking the “First vaccine available is the best vaccine” is we get the feeling that NACI is a Puppet and Federal Gov is the Puppeteer.

        It is frustrating to have the puppet jerked in many different directions or twisted to make the Puppeteer look good.

        The problem for anyone who listened to the puppet and took AstraZeneca, is the rapid and constantly changing contortions the puppeteer seems to be putting the puppet through. This leads to the audience not trusting either of the puppet or the puppeteer to the point where it feels like there is negligence in the puppet show.

        I should not have conflated ELM to NACI but the whipsawing of changing recommendations might result in many in the audience to conflating NACI as the Medical People; and this might result for some who listened and trusted the marionette show of NACI, to then lose some trust in medical community by conflating NACI to Medical, this would be a shame. I have great faith and trust in the medical professionals (nurses and doctors) but for an AstraZeneca 1st dose person, NACI (by medical association) could test that faith for some.

        Frankly, feels to me the puppet show is being made up “on the fly” by a master puppeteer in order to look good or maybe call a federal election once there are a ton first jabs in arms. If the puppet masters are interfering with NACI, we might end up having more than 30% of citizen not listen and ending up being anti-“this, that and everything”. I hope that some entitled persons, who are lazy, do not do the work, and instead just ask google for answers are not the ones determining what are NACI recommendations, good lord, seems like half the population is doing that now.

        People need to do their part…but the powers need to not instill doubt…by either making it up or changing the recommendation so darn quickly, or just asking google what to do. I know its a fluid situation but as an AstraZeneca person, “many people” (not channeling Doffus RUMP) are upset for me (and for us as a collective) …and that sows doubt to those paying attention.

        Hoping to get number 2 dose as AstraZeneca

  • Saskia says:

    Since the pandemic has started, I’ve trusted the experts’ opinion in all aspects of navigating the changes, updates and expectations publicized in the media. And now I feel, in certain way, discriminated against only because I was a good citizen who took the first available vaccination (AstraZeneca) despite having an option to receive either Pfizer or Moderna only 4 (four) days later.
    I got my dose #1 on April 10, and now I’m expected to wait 12 weeks to get my dose #2 (regardless of the brand I would choose), while those who got their Pfizer or Moderna dose #1 before May 09, can start booking their dose #2 immediately. It’s hard to understand and accept it, knowing that individuals age 60-65 who got their AstraZeneca dose #1, received their dose #2 after only 10-week interval. It is even more difficult to understand considering the stress on the importance of getting dose #2 to be protected better against new variants; not to mention the just announced possibility to travel without the need to stay in an airport hotel if one has received both doses of anti-Covid vaccination.
    Why do people like me have to wait these 12 weeks either for AstraZeneca or other vaccination? We were the “good ones” who followed the advice that the best vaccination is the first one available, and now it seems, we are being punished for this attitude. If there is any scientific explanation to this different treatment, I have not found it yet. In UK, USA and other countries, the intervals have been much shorter, often only 5-8 weeks between each dose.
    Today (June 10), some discussion has been started on implementing a lottery to encourage people for taking dose #1 and/or #2 – well, I don’t need to be lured by any lottery – I simply want to be vaccinated with dose #2 and I’m not given this opportunity. Cleary, I feel like a second-class citizen. And very naive one, as I did trust the original advice given in March and April!

    • Simmerdeep says:

      I got My first dose on May 1 – Astra zeneca .
      Today i went walk in to get my second dose , i chose Pfizer as going through studies it shows that its ever more wffective if you have sexond dose of Pfizer/moderna after first Astra zeneca .

      I went walk in as i have travel plans ahead and it will be much easier to travel back and
      Avoid quarantine.

      I recommend not to wait and just go walk im to any vaccine clinic and they will give you Pfizer/moderna shot .

      • Wade says:

        How are you feeling after getting Pfizer for your second dose? Any side effects?

      • JM says:

        When you say 2nd dose of Pfizer/Moderna, you mean the booster right? Got a bit confused if I should take the primer or booster for my 2nd dose. God bless.

      • SE says:

        Pfizer isn’t more effective. Please look at my reply’s above. I have their actual studies. They change the results and mess with the variable to make more favourable results but even then they still end up altering them. Pfizer is less than 1% effective according to their own studies. They can only show better results when they put their vaccine after Astra Zeneca and that’s due to the effectiveness of Astra Zeneca and not them. They know this. It’s why they have stopped slamming Astra Zeneca in the news. You know those blood clots aren’t even caused by Astra Zeneca. It’s a genetic disorder already in the patient and it’s less than 1% chance you will have it. Plus with the knowledge of the symptoms now they have gotten the deaths down to almost zero. Whereas people are still dying from Pfizer and those deaths are from the actual vaccine itself not a rare genetic disorder. Plus the thousands of people daily that have severe allergic reactions. If I’m the only person in the world that is talking about this then I’ll keep doing it till they stop me. You can find this stuff it’s from Pfizer themselves but it takes work. I have pictures because they take it down after time. I’m very good at research and I have access to medical sites from my medical training.

      • halil Guzelbaba says:

        Hi, Where did you have the second dose? I am going to go abroad. I have to get a second dose

    • Joel says:

      I read you comment and I had to chime in my frustration too.

      AstraZeneca in Niagara

    • Isabel says:

      I am in the exact situation as you, I even took my first dose of Astra Zeneca on the same day as you was so excited to get it only to be now frustrated and angry . When you read and hear about how other provinces have reduced the wait time to 8-10 weeks and we here in Ontario have to wait 12 weeks is something I can’t wrap my head around. I am a big advocate that everyone needs to do their part and get vaccinated as quickly as possible so that life can go back to “normal” , but now I wish I had waited to get Pfizer so that I would not be in this situation, my husband received both his 2 doses of Astra Zeneca because he received early March the 1st and was offered the 2nd dose just before the so called expiry doses were due… both my children that received their 1st doses of Moderna early May are already scheduled to receive their 2nd doses next week and here I am frustrated that as of today the earliest that I can get my second dose is July 10.
      Something needs to change….

      • SE says:

        Please read what I wrote and don’t get Pfizer I’m sorry your kids got moderna it’s the same thing. Made the same way and not effective. If you can get Astra Zeneca it is worth it. Pfizer won’t protect you and you have a large chance of react now and in the future as well.

      • B Rebel says:

        Rules have changed in Ontario. Just announced. Now you can get a second shot in 8 weeks after your first AZ dose.

    • SE says:

      I’ve written my response about five times. Don’t know what is happening. It won’t paste. I bet this does though. There is a scientific reason. Have a look through my responses SE is all me. I’m kinda over spending an hour and it not posting. Don’t get Pfizer. You are acting very entitled we all are going through this. Also you can’t just travel because you have the vaccine. Canada and the US are being idiots about this. That’s why we have the highest infection rates. My province Alberta is rushing so they can do stampede. No brains in their head at all. Selfish and obviously haven’t had someone sick or die.

      • kenan says:

        It’d be nice if you give links to these absurd claims of 1% efficacy. If this was the case, how do you explain sharp decreases in infection rate in the US?

      • Thomas V. says:

        Are you shorting Pfizer and Biontech stocks ? Millions have gotten it in the last 6 months and have avoided getting Covid in the US, Israel, UK and other countries.. So everyone is lying except you ?


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