Getting a Booster Too Soon Could Cause This Serious Side Effect, Experts Warn

In the U.S., COVID booster shots are expected to be rolled out starting Sept. 20, under guidance from the Biden administration. But while both the Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) still need to decide on the specific rollout plans, including who will be eligible for additional shots first, it seems clear many people are eager to take the extra protection if they can get it. The CDC reported in early August that more than 1 million people had gotten a third dose already, despite not being authorized to receive a booster shot yet. But experts are now warning that going for a booster too early could put you at risk. A group of scientists, including two senior FDA officials and the World Health Organization (WHO), published a study in The Lancet on Sept. 13 indicating that booster shots are not yet needed for the general public. In fact, getting these jabs too soon could have negative consequences.

According to the scientists, distributing boosters too early may lead to the potential for more vaccine-induced side effects, like myocarditis. Myocarditis is a rare heart inflammation condition that has affected hundreds of young adults, and it's significantly more common after second doses of the mRNA vaccines than first doses.

"If unnecessary boosting causes significant adverse reactions, there could be implications for vaccine acceptance that go beyond COVID-19 vaccines," the study authors warn. "Thus, widespread boosting should be undertaken only if there is clear evidence that it is appropriate."