F.D.A. Allows updates of Covid injections for children from the age of 6 months

The ruling expands access to reformulated injections, but only a small fraction of the country's youngest children are likely to receive one of the new doses in the near future.

WASHINGTON — The Food and Drug Administration on Thursday expanded eligibility for updated coronavirus vaccines to children as young as 6 months old, the final step to making the revamped doses available to more Americans.

The federal government rolled out the updated boosters from Pfizer-BioNTech and Moderna in September, though that the public has shown little interest in new vaccines. The government expanded eligibility to children as young as 5 in October.

The F.D.A. further expands access to so-called bivalent vaccines, although there is unlikely to be a high demand for them among parents. Only a small fraction of the country's youngest children have been vaccinated since the original vaccines were licensed for this age group nearly six months ago.

The move comes as cases of coronavirus in the United States are on the rise. Young children have also been hit hard in recent months by the respiratory syncytial virus, known as R.S.V., with cases overwhelming pediatric units across the country. And this year's flu season promises to be severe; more than a dozen children have already died.

"More children now have the opportunity to update their protection against Covid-19 with a vaccine bivalent against Covid-19, and we encourage parents and carers of eligible people to consider doing so – particularly as we approach the holidays and the winter months when more time will be spent indoors,” F.D.A. Commissioner Dr. Robert M. Califf said in a statement.

For the nation's youngest children, eligibility for vaccines updated day will vary depending on the vaccine and the number of doses they received.

Children aged 6 months to 5 years who received the two-dose vaccine of Moderna will be eligible for the company's updated booster two months after completing their initial vaccination cycle.

Pfizer's vaccine is approved. inistered in three doses for children aged 6 months to 4 years. For these children, the third dose in the series will now be the updated dose instead of the original formulation.

Young children who have already received all three Pfizer's series doses will not yet be eligible for an upgraded booster. But the F.D.A. said it expected new data to become available in January regarding the refitted booster for this population, and the agency said it would assess that data "as soon as possible."

< p class="css-at9mc1 evys1bk0">Expanded eligibility for updated vaccines has yet to be approved by the Centers for Disease Control and Prevention.

The Biden administration has struggled to generate interest in the updated recall shots, which target both the original version of the virus and Omicron subvariants. So far, only 13% of Americans ages 5 and older have received one of the new doses.

The F.D.A. authorized Pfizer and Moderna vaccines for the nation's youngest children in June, a decision that came a year and a half after the vaccines were first rolled out for adults.

But few young children have been vaccinated since then. So far, less than 10% of children aged 4 and under have received their first dose of vaccine, and even fewer have completed their full series of vaccines.