FDA review finds Moderna’s booster dose of its coronavirus vaccine strengthens disease-fighting response

A Food and Drug Administration review released Tuesday found that a booster shot of the Moderna coronavirus vaccine enhanced virus-fighting antibodies in people who had received the standard two-dose regimen at least six months earlier.

The document, like a previous review of evidence for a booster of Pfizer-BioNTech, struck an ambivalent tone about whether boosters are needed now.

FDA reviewers noted that a half-dose booster shot of the Moderna vaccine topped off the level of antibodies, the most easily measurable barometer of immunity. But they also pointed out that the utility of a booster will depend on factors that are unclear at this moment – such as whether the protection of initial vaccination has dropped substantially.