Sunday, September 26, 2021

What is the scoop on boosters?

Are you feeling confused about Covid vaccination boosters? Join the crowd. So, it appears, is almost everyone in Washington (and everywhere else).

What do we know? What should you do?

We know that the mRNA vaccines remain very effective at preventing serious infection, though it is certainly possible for vaccinated people to catch and spread the virus.

While the Pfizer and Moderna vaccines were in a dead heat (95% vs. 94%) in effectiveness based on the original trials, the Moderna vaccine seems to hold up better. This may be because it uses a higher dose (100 vs. 30 micrograms) and/or because the longer time between doses (4 weeks vs. 3) is better for developing immunity – the longer the better is true for most vaccines.

A study from the CDC found that while both mRNA vaccines offered 90% + protection for the first 4 months after vaccination, this fell to 77% for Pfizer while staying the same for Moderna.

Pfizer has said that antibody levels increased 3-fold in a small (300 subjects) set of volunteers given a booster 5 to 8 months after their initial series. The use of a booster is also supported by data from Israel, where immunity seemed to fade over time but was restored to 95% by a booster in people 60 and older (Israel used almost entirely the Pfizer vaccine).

Finally, the J&J vaccine was less effective than the two mRNA vaccines, but one small study found no drop in antibody levels over 4-6 months, and another found that a booster of the same vaccine made antibody levels rise nine-fold.

There has been no testing of using a different vaccine as a booster to one of the three approved in the U.S., but a study done in Britain found that following the Astra Zeneca vaccine with the Pfizer gave much better protection than using the A-Z vaccine alone (and the A-Z vaccine uses similar technology to the J&J shot). It is unlikely that “mix and match” would be harmful.

The FDA recently approved using the Pfizer vaccine booster for select groups, and the head of the CDC advised broadening the groups eligible.

So… what should you do?

If you got the Pfizer vaccine, had no major side effects and are in a high-risk group, get it. It will be free, and the best evidence we have now says it will improve your protection. The side effects of a third shot were similar to those of the first two. If you are young and healthy, I would not recommend it until we have more data.

If you got the Moderna vaccine, you seem adequately protected. When Moderna’s booster is approved, I would follow the same advice: high-risk (including age) yes, otherwise wait.

If you got the J&J shot, talk to your doctor about possibly using the Pfizer booster “off-label.” Since it is now fully approved, he or she can prescribe it if they feel it is indicated.

Prescription for Bankruptcy. Buy the book on Amazon

No comments:

Post a Comment