The mRNA technology behind Moderna’s Covid vaccine reaches the flu

The Food and Drug Administration has approved a new kind of flu vaccine for older people, the first made with the same mRNA technology that was key to ending the Covid-19 pandemic, Moderna, the manufacturer, said.

The shot, named mFlusiva, is intended for adults aged 50 or older. Other brands of flu shots already have begun arriving in pharmacies ahead of fall vaccination season, and Moderna said late on Wednesday that it expected some of its new version to be available soon at select retailers.

While there already are multiple flu vaccine options in the US, including three specifically recommended for people age 65 or older, tens of thousands of Americans die from influenza every year and older adults are among the most vulnerable.

Flu vaccines must be updated annually to best match circulating strains of the virus. Vaccines made with the Nobel prize-winning mRNA technology are faster to manufacturer than other types, and experts say this additional option might help if the shape-shifting flu virus mutates in a way that requires suddenly brewing new doses.

Moderna, which is based in Cambridge, Massachusetts, said the FDA granted full approval for mFlusiva’s use in people ages 50 to 64, based on a study of 40,000 people that found the new shot reduced flu cases by about 27% compared with another routinely used flu vaccine brand. For people 65 or older, the biotech and pharmaceutical company said the FDA granted what’s called accelerated approval for the shot – based on a smaller study showing it generated a strong immune response compared with an existing high-dose vaccine for seniors – while it conducts an additional postmarketing study.

Moderna’s data showed no major safety issues although the shot did cause some temporary reactions including injection site pain, fever, headache, tiredness and aches that occurred somewhat more than with today’s flu shots.

The FDA action comes after a highly unusual public dispute over mFlusiva earlier this year. A then top FDA official blocked the company’s application, a sign of the agency’s heightened vaccine scrutiny under the health secretary, Robert F Kennedy Jr. Days later, the agency changed course after Moderna publicly challenged the ruling – and in June a panel of independent advisers to the FDA unanimously recommended the vaccine’s approval.