Reported SUSAR Delays AstraZeneca AZD1222 Phase 3 Trial: Pressure Mounts as this Vaccine Could be the Nov Candidate

Sep 9, 2020 | AstraZeneca, AZD1222, COVID-19, News, Popular Posts, SUSAR, Vaccine

Reported SUSAR Delays AstraZeneca AZD1222 Phase 3 Trial Pressure Mounts as this Vaccine Could be the Nov Candidate

AstraZeneca reports in a statement to News Nation Now that an apparent suspected serious adverse reaction (SUSAR) occurred in the United Kingdom with AZD1222 during the Phase 3 clinical trial. Now the late stage studies are on hold, as TrialSite reported earlier on Tuesday, September 8, in India due to a serious side effect linked to the administration of the experimental vaccine. This delay is notable as AZD1222 is the subject of serious chatter concerning its potential as an early emergency use authorization (EUA) target.

Company Statement

AstraZeneca issued a statement Tuesday evening that its “standard review process triggered a pause to vaccination to allow review of safety data.” The UK-based company didn’t reveal anything about the event other than it was “a potentially unexpected illness.”

The company made the following statement to News Nation Now:

As part of the ongoing randomized, controlled global trials of the Oxford coronavirus vaccine, our standard review process was triggered and we voluntarily paused vaccination to allow review of safety data by an independent committee. This is a routine action which has to happen whenever there is a potentially unexplained illness in one of the trials, while it is investigated, ensuring we maintain the integrity of the trials. In large trials illnesses will happen by chance but must be independently reviewed to check this carefully. We are working to expedite the review of the single event to minimize any potential impact on the trial timeline. We are committed to the safety of our participants and the highest standards of conduct in our trials.

Big Stakes

TrialSite reported that this particular Phase 3 study, at least in the United States, include an unprecedented compression from estimate startup date to estimated primary completion date of about 3.5 months.

TrialSite has conveyed that chatter in the Financial Times and other sources indicates this particular study is on the U.S. White House’s radar as a candidate for an emergency use authorization (EUA) but as reported in TrialSite, generally studies in the West are more focused on safety and rigorous process than expediency.

Deal Making

Back in June, CNBC reported on the fast and furious deal making where AstraZeneca committed to distribute 1 billion doses of AZD1222 to not only low-and middle-income countries (LMICs) but also to the U.S. and UK by September. The vaccine, originally developed at Oxford, looks to have been identified months ago as a candidate for a “November surprise.”

Behind the Game

As the AZD1222 study just started, in the meantime two other vaccines are in the final stages of testing in the United States, including Moderna (mRNA-1273) and Pfizer (BioNTech partnership) and BNT162A. Both of these trials work quite differently than the AZD1222 and the studies have recruited nearly two third of the total subjects needed.

Call to Action: TrialSite monitors these studies on a daily basis and will keep an eye out for material data points. Sign up for the free daily newsletter for updates.


  1. Bobsie MacDougall

    Re: “TrialSite reported that this particular Phase 3 study, at least in the United States, include an unprecedented compression from estimate startup date to estimated primary completion date of about 3.5 months.”

    Comment: A leading industry spokesperson is pushing to have health-care workers be the first to be vaccinated!

    If just a few weeks into the trials we have SUSARs, what should we expect after a few months of vaccinations in the general public?

    Remember this — a huge methodology issue in these experimental designs is generalizability of results to a real population. It is rare, if not impossible, for even a 30,000 sample experiment to capture all the relevant causal-relevant heterogeneity (in population attributes and behaviour) that comes into play once general vaccination is deployed. So, basically, once you move from the experimental setup to the general population all you can do is get on yours knees and pray.

    That is why I dow not want my doctor and nurse to be ‘first receivers’ of the vaccine. This is especially so, when everybody knows that the savvy doctors and nurses are *already* quietly using regimens designed to help them beat off a COVID-19 attack, and that when attacked they know that if they can respond within the first six days of infection there are protocols that will greatly help their chances of getting off with nothing more than a flu.

    • John Hainaut


      Brilliant and succinct analysis. I am not a medical or biological scientist. I’m just a retired engineer trying to understand what I can about COVID-19.

      This and other comments you have made on this site are invaluable to that understanding. Thank you!

  2. Jsck Dougherty

    I’m hiv positive for 25 yrs still undetectable I’m interested in volunteering if possible

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