An assessment released by the Food and Drug Administration (FDA) on Wednesday shows that the Johnson & Johnson vaccine booster shot proved effective in increasing study subjects’ immune defenses.
The FDA added, however, that data was limited and that a test used by Johnson & Johnson to prove effectiveness may not have been sensitive enough.
The report comes in just ahead of a two-day meeting of FDA advisers on Thursday in which the committee will discuss recommending booster shots for the Moderna and Johnson & Johnson COVID-19 vaccines.
Moderna seeks authorization of a third dose of its vaccine that is a half-sized dose for certain high-risk groups at least six months after initial immunization.
Johnson & Johnson hopes to secure approval of a second dose of its vaccine two months after the first shot for vulnerable groups and six months after initial vaccination for others.
The FDA usually follows the conclusions of its experts, but it is not required to do so.