Boston’s Nathan Jacobs gets his Covid booster shot from Sassy Yogurtian on December 9, 2021 at City Hall in Boston, MA.
Stuart Cahill | MediaNews Group | Getty Images
People in the US may need another Covid booster shot this fall as public health experts expect immunity to the vaccines to wane and transmission of the virus to increase in the colder months, the Food and Drug’s top vaccines official said administration on Tuesday.
dr Peter Marks, head of the FDA’s office responsible for vaccine safety, warned that the US may have to offer fourth shots for people under 50 in the fall. People who are now eligible for fourth shots would likely get a fifth shot if there is evidence that would be beneficial, Marks told reporters on a conference call.
Marks also said the US could switch to a different vaccine that targets a specific Covid variant or a mix of several. Current vaccines were developed against the original virus that emerged in Wuhan, China in late 2019, and their effectiveness has decreased over time as the virus mutates. Pfizer and Moderna are conducting injectable clinical trials targeting both Omicron and other circulating variants.
The FDA will hold an advisory committee meeting on April 6 to discuss the future of booster vaccines in the United States and whether vaccines need to be updated to provide better protection against variants.
“It wouldn’t be surprising if there’s a potential need for people to get an additional booster in the fall along with a more general booster campaign, if that happens,” Marks said. “It may be that a decision will be made that instead of the vaccines that we currently have, which are called prototype virus vaccines, we move to a vaccine that is either against one of the variants or against something else.”
CNBC Health & Science
Read CNBC’s latest global coverage of the Covid pandemic:
The FDA on Tuesday approved a fourth dose of Pfizer and Moderna’s original vaccine for people age 50 and older. The drug agency also approved a second booster shot for younger people with compromised immune systems. Individuals 12 and older with certain underlying medical conditions are eligible for Pfizer, and individuals 18 and older with the same medical conditions are eligible for Moderna.
According to Marks, evidence from Israel suggests that a fourth dose may reduce the risk of hospitalization and death in older adults. The more contagious Omicron subvariant BA.2 has triggered new waves of infection in large European countries as well as in China. The subvariant is now dominant in the US White House medical adviser Dr. Anthony Fauci said earlier this month that BA.2 could lead to a spike in infections in the US, although he doesn’t expect a further spike.
Marks said the FDA has decided to offer older adults a fourth dose and a fifth shot to certain immune-compromised people so they have the tools to protect their health if another wave hits the US
Scientists and public health officials are divided over whether more booster shots are needed at this time. Israeli scientists found that a fourth dose significantly reduced mortality in people aged 60 and older compared to people who received three vaccinations. The study, conducted by Ben-Gurion University and Clalit Health Services, Israel’s largest healthcare provider, was not peer-reviewed.
However, another Israeli study of health workers aged 18 and older showed that the fourth dose did not boost immunity in younger adults, many of whom still had asymptomatic and mild breakthrough infections.
“A fourth shot of healthy young health workers may only have marginal benefits,” wrote Drs. Gili Regev-Yochay and a team of scientists from Sheba Medical Center and the Israel Ministry of Health who conducted the study, in a letter to the New England Journal of Medicine this month.