Booster shots of Moderna Inc.’s COVID-19 vaccine should be given to older people and those at high risk of the disease, advisers to U.S. regulators said.
Additional doses of the two-shot messenger RNA vaccine should be offered to people 65 and older, along with adults 18 and older who are at high risk for medical or occupational reasons, the Food and Drug Administration’s vaccine advisory panel said Thursday in a 19-0 vote.
The booster, which is half the original dose, should be given at least six months after the initial inoculation, the panel said.
Moderna shares gained as much as 4.9% in Thursday afternoon trading in New York.
The vote follows a similar recommendation from the panel on a booster from Pfizer Inc. and BioNTech SE, which has since been cleared by the agency in older, higher-risk populations. Moderna presented data to the panel indicating that its vaccine loses efficacy over time, and that a booster shot is safe and can help restore levels of protective antibodies.
President Joe Biden has championed the booster program as one of the keys to controlling the pandemic and heading off the emergence of new variants. However, critics have said the initial immunizations continue to prevent severe illness, and booster programs reduce supplies needed by countries that still lack vaccines.
Panel members agreed that the data Moderna presented to support the booster was thin, particularly the safety data for the half-dose booster. But they ultimately decided that it was good enough in the face of a continuing pandemic, amid signs that at least some at-risk people could develop serious breakthrough cases.
On safety, the experts were reassured by the fact that many people with weak immune systems have already gotten a full third dose of the Moderna shot with no apparent problems so far.
“These are extraordinary times, and we have to work with imperfect data,” said Eric Rubin, a panel member at the Harvard T.H. Chan School of Public Health, summing up the opinion of many panelists.
The FDA will now decide whether to grant a clearance. The agency doesn’t have to follow the advisory panel’s preferences, and can make its own determination about whether to authorize the booster and for what populations.
Once the FDA acts, the baton will be passed to the Centers for Disease Control and Prevention’s separate advisory group.
The CDC’s Advisory Committee on Immunization Practices is scheduled to meet on Oct. 20 and 21. The panel will make its own recommendations on boosters and share that language with CDC Director Rochelle Walensky, who will then decide whether to adopt it or shape her own recommendations.
The FDA’s advisory committee will continue meeting today, when it considers booster shots from the third company with an authorized COVID vaccine, Johnson &Johnson. The single-shot J&J vaccine has had far less use than Moderna and Pfizer-BioNTech.
The end of the meeting will feature a discussion on mixing and matching boosters with different shots used in initial immunizations.
Pairing COVID-19 immunizations with a different booster produces as much or more antibodies as boosting with the same shot, according to preliminary results from a U.S. government-sponsored trial released Wednesday.