BA.2 and Pfizer’s fourth booster shot

Two things have been buzzing this week, and both are confusing.

Multiple people have been trumpeting the fact that there has been an uptick in COVID infections in certain European countries over the past three weeks. They attribute this to the presence of a variant of Omicron called BA.2. This variant has been reported to be “more contagious” than the original, Omicron variant, but no one has shown it to cause worse illness, be more deadly, or escape the current vaccines.

Recent uptick in cases in Germany, the UK and France.

I think the biggest problem here is that people continue to focus on infection numbers and not outcomes. With each day and each wave of infection, more and more people have been infected, on top of those who are vaccinated. Thus, each new variant becomes less impactful. While these viruses may cause brief infections, many of which are asymptomatic, in vaccinated or previously infected people they do not cause illness.

Rather than raising issues about infections from these variants, influencers should reinforce the need for vaccination. If everyone were vaccinated, you would not see any issue at all from these viruses. As it is, no one believes that this particular variant is going to cause a huge boost in infections in the United States.

Seemingly playing off the concerns about BA.2, Pfizer has suggested it’s time for a fourth booster shot. This shot would not be a unique booster but would be a fourth shot of their current vaccine. The data they use for this is a brief study from Israel that for a brief period of time, after the booster, infections are decreased. This benefit was observed mainly in people over the age of 65. Again, this booster does not seem to offer a huge increase in protection from serious illness or death which are both strongly protected against with just the three shots.

While it is possible that as immunity wanes over the next six months, at some point doing another booster would seem to make sense, the current situation doesn’t seem to warrant an immediate call for another booster across the population. It is not clear why Pfizer is advocating for this at this time, but using these short-term studies in Israel to try to justify it seems counterproductive and may lead people to avoid taking a fourth booster shot when it is needed at a later point in time.

Therefore, on both the BA.2 variant and the fourth Pfizer shot please limit your concerns because the data doesn’t support a need for action.

Published by jbakerjrblog

Immunologist, former Army MD, former head of allergy and clinical immunology at University of Michigan, vaccine developer and opinionated guy.

3 thoughts on “BA.2 and Pfizer’s fourth booster shot

  1. Do you feel that immunocompromised people should take the 4th shot and then Eveshuld? Thank you for your excellent ponderings!


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