Moderna asks FDA for authorisation for a second booster for all adults

Moderna said late Thursday that it asked the Food and Drug Administration for emergency authorisation of a second booster of its coronavirus vaccine for all adults, a significantly broader request than Pfizer and BioNTech filed for their shot this week.

The request is likely to intensify the latest round of an ongoing scientific debate over how long protection from the two most-used vaccines in the United States lasts in the face of new variants.

On Tuesday, Pfizer and its German partner, BioNTech, asked for emergency authorisation for a second booster for those 65 and older. The request was based heavily on data from Israel, where such shots are authorised for a somewhat broader group.

Federal health officials have said they are concerned about waning potency of the booster shot that was authorized for Moderna and Pfizer in the fall. Although there are indications that regulators could move swiftly on Pfizer’s request, it is unclear how favourably they will view Moderna’s more sweeping application.

Moderna said its request covered all adults, so the Centres for Disease Control and Prevention and health care providers could determine the appropriate use of a second booster, including for those at higher risk of COVID-19 disease because of age or underlying medical conditions. Pfizer said the request was partly based on recent data on how well its vaccine protected against the omicron variant in the United States and Israel.

Outside scientists are sharply divided over whether another dose is necessary now, and if so, for whom. “I’m a strong proponent of giving a second booster now,” said Dr Peter J Hotez, a vaccine expert at the Baylor College of Medicine in Houston.

He said the first booster shot had “made a huge difference” in bolstering protection against hospitalisation and even infection from the omicron variant.

“It’s also clear that protection is waning now pretty quickly a few months after your third dose,” he said. “So it’s short-lived. The hope is that a second booster would restore it.”

But Dr Jesse L Goodman, a former chief scientist for the FDA, said: “While protection is waning against mild infections, without more information we do not yet know to what extent, if any, protection is waning against severe disease.” Nor is it clear, he said, “to what degree and for how long another booster might help.”

Among the data the companies cited was a study released last month by the CDC that found the effectiveness of Pfizer’s and Moderna’s vaccines against hospitalization dropped from 91% two months after a booster shot to 78% after four months. The study presented a broad snapshot; it did not break down hospitalisations by age, presence of underlying conditions or other factors.

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