“The CDC and FDA were waiting on sufficient data to show that booster shots are safe and recommended for the general adult population, which they now have,” says Dr. Marcus R. Pereira, medical director of the Transplant Infectious Diseases Program at NewYork-Presbyterian/Columbia University Irving Medical Center and assistant clinical professor of medicine in the Division of Infectious Diseases at Columbia University Vagelos College of Physicians and Surgeons. “These actions were based on new data showing an increase in the immune response after a booster shot.”
Health Matters spoke with Dr. Pereira about the latest guidance and data on booster shots.
What have the FDA and CDC decided about COVID-19 booster shots and why?
After the White House made an initial recommendation for booster shots two months ago, scientists from the FDA and CDC have closely monitored data and confirmed that vaccine protection may decrease over time. For example, studies in the United States have found that among essential workers, vaccine effectiveness against infection waned in July, though severe disease remained rare.
For this reason and because of the rise of the more contagious Delta variant, a booster shot is now recommended for anyone over the age of 18 who finished their mRNA series at least six months ago or received the Johnson & Johnson vaccine at least two months ago.
By changing the eligibility criteria, the guidance is now less confusing. They’re telling the general public, absolutely get a booster. And the time to do it is now, before the holidays and the new year.
Are booster shots safe?
Yes, booster shots are proven to be safe. Pfizer released a study of 10,000 participants in which half of them received a booster dose and half a placebo. In terms of safety, they found no new adverse events, meaning it was consistent with what has been seen in previous studies. For those concerned about myocarditis or pericarditis, inflammation of the heart muscle or the outer lining of the heart, no cases of either were observed. In fact, the placebo group had more serious adverse events than the booster group.
In addition, the CDC found that reactions from the third dose were very similar to those after the second dose, stating that there are “no unexpected patterns of adverse reactions” and they will continue to monitor the boosters’ safety. The benefit outweighs any risks of receiving either the Pfizer or the Moderna booster dose.
Are booster shots effective?
The booster shots are not only safe, they are also shown to be very effective in boosting one’s immunity to COVID-19. In the Pfizer study, they found that the relative vaccine efficacy after the booster was more than 95%, which restores the original vaccine efficacy before immunity waned.
Moderna is still accumulating final data, but since Moderna has been shown to produce a good amount of neutralizing antibodies and total antibodies, we expect the efficacy to be on par with the Pfizer results.
It should be noted that the Moderna booster is only half the original dose. This is because the initial two doses of the Moderna vaccine were much higher comparatively speaking than the Pfizer, so individuals need only half a dose for boosting.