No Really, You Shouldn’t Get a Booster Shot if You’re Immunocompetent
A friend of mine is very worried about the Delta variant. He received an AstraZeneca Covid-19 vaccine last spring in Mexico, where he lives part-time, and then a Johnson & Johnson vaccine in the U.S. a couple of months later. But he was still nervous, so in the past few weeks he received the two-dose series of the Pfizer/BioNTech vaccine as well.
Many epidemiologists and public health authorities, including the World Health Organization, have made strong ethical arguments against citizens of rich countries receiving booster shots while most of the world still doesn’t have access to vaccines at all.
But abstract concerns about vulnerable people in distant countries are generally not as compelling as individuals’ desire to increase their own immediate sense of protection, here and now. So despite the WHO’s plea to hold off on boosters until more people around the world have been offered their first shot, many in the U.S. are seeking out boosters on their own.
But is this actually increasing their protection? And is it safe? In the absence of robust clinical trial data, we don’t have answers to these questions. And the potential safety risks should not be dismissed.
“This is akin to the problems we see when people keep old medicines in their medicine cabinet and self-treat,” says Gregory Poland, MD, a vaccinologist at Mayo Clinic in Rochester, Minnesota, and the director of Mayo Clinic’s Vaccine Research Group. “A whole variety of problems and issues can occur.”
Late booster vs. variant-specific booster
First, it’s important to define two distinct types of boosters. In the case of Covid-19 vaccines, a “late” booster is a third dose of the same mRNA vaccine someone received the first time around (or a second dose of the single-shot vaccines, such as Johnson & Johnson and AstraZeneca).
Then there’s a variant-specific booster, which is tweaked to prime the immune system to recognize a mutated version of SARS-CoV-2, such as the Delta variant.
Vaccine manufacturers are actively pursuing and studying both kinds of boosters.
