For the first time since the COVID-19 vaccines rolled out in December 2020, we have updated shots that match the primary variants in circulation. Unlike the original vaccine, which targets the ancestral virus strain, the new boosters specifically target Omicron BA.4 and BA.5, which are now dominant in the United States and responsible for most new COVID-19 cases across the country.
On August 31, the U.S. Food and Drug Administration authorized the use of these updated boosters and the Centers for Disease Control and Prevention endorsed them on September 1. These decisions have come as immunity conferred by prior vaccination or infection is waning against these highly contagious versions of Omicron. Scientists are predicting an increase in COVID-19 infections in the fall and winter.
Giving the original COVID-19 shot as a second or third booster would probably help increase antibody levels against the virus, said Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, at an August 31 virtual news conference. But the idea with the updated vaccine is also to achieve a longer duration of protection. It will take several months before researchers can collect the data and determine whether this will happen. No matter how incremental the benefits are from the reformulated shot, Marks said, “It’s really important for people to think about getting boosted.”