4:13 PM, Feb 27, 2020


Ask Dr. Nandi: Pfizer Says COVID-19 Vaccine 90% Effective Against Virus

Posted at 9:54 PM, Nov 09, 2020

Making headlines nationwide and around the world, the pharmaceutical company Pfizer has announced that its vaccine is 90% effective at preventing COVID-19.

That according to early data from their clinical vaccine trial.

First of all, I have to say what great news this is. I’m so pleased to be sharing this because I know that a vaccine will have a serious impact on this pandemic. Especially if what Pfizer said holds true, that its vaccine provided protection just 7 days after participants got their second shot.

But, how many COVID-19 cases did Pfizer document so far? 94. There were 94 confirmed cases in the interim analysis.

Now, I know what you’re thinking, that does not seem like a lot since over 43,000 have volunteered. But this study is not finished. Pfizer is monitoring all of the participants for a full two months. And that two-month mark ends about the third week of November.

Remember we have two groups here. Half got the vaccine and the other half got placebo shots. And about 90% of those who caught the virus were in the placebo group. While roughly 10% of the infections were in the group that got the vaccine.

But I have to be honest here and say, that those numbers might already be slightly skewed, and here’s why. Pfizer did not test everyone in the trial. They only tested participants who developed symptoms. And we all know now that you can catch this virus and be asymptomatic.

Having said that, even if the 90% rate drops, it just has to be 60% or above regarding effectiveness. Because that’s what’s needed to apply for emergency authorization or approval.

It’s quite possible that the 90% effectiveness could change. Mainly because the study is ongoing. And Pfizer needs to have at least 164 confirmed COVID cases documented as outlined by the FDA. So they still need to document 70 more cases which could impact the current interim efficacy rate.

Question: The vaccine was projected to be ready by the end of the year, any chance it’ll be ready sooner?

It’s unlikely. First of all, Pfizer would need to seek emergency use authorization from the FDA. Which they are planning to do later this month.

Assuming they are granted this, I believe we'll have limited doses at first that would need to be rationed out. However, Pfizer has said they plan to have 50 million vaccine doses that would be available globally this year. With the goal of making 1.3 billion next year.