Marathon US hearings to decide fate of COVID shots for tots
Parents anxious to finally vaccinate their youngest children against COVID-19, strap in: A lot is set to happen over the next week.
On Wednesday, both Moderna and Pfizer will have to convince what’s essentially a science court — advisers to the Food and Drug Administration — that their shots work well in babies, toddlers and preschoolers.
Kids under 5 are the only group not yet eligible for COVID-19 vaccination in the U.S. If the agency’s advisers endorse one or both shots for them — and the FDA agrees — there’s still another hurdle. The Centers for Disease Control and Prevention must recommend whether all tots need immunization or just those at high risk from the virus.
Adding to the complexity, each company is offering different dose sizes and number of shots. And the week won’t even start with the littlest kid debate: Moderna first will ask FDA’s advisers to support its vaccine for older children.
Only a handful of countries, including China and Cuba, have offered different types of COVID-19 vaccinations to children younger than 5.
Pfizer has a pediatric track record — its COVID-19 vaccine is the only type the FDA allows for children of any age. Two doses plus a booster are cleared for everyone 5 and older. Shots for the 5- to 11-year-olds contain a third of the dose given to teens and adults.
For kids younger than 5, Pfizer and its partner BioNTech lowered the dose even more, to a tenth of the adult dose. The trade-off is a need for three shots, the first two given three weeks apart and the last at least two months later.
Moderna is seeking FDA clearance for two shots, each a quarter of its adult dose, given about four weeks apart for kids younger than 6. (Moderna tested a slightly different age limit than Pfizer.)
The FDA currently allows Moderna’s vaccine to be used only in adults. But some countries allow two full-size doses for teens and half-size shots for kids ages 6 to 11 — which Moderna also hopes to offer in the U.S.
Pfizer disappointed parents back in December when a study found two shots weren’t quite strong enough. So researchers tested a third shot in youngsters age 6 months through 4 years during the winter surge of the omicron variant.
Pfizer’s preliminary data showed after three shots, children developed high levels of virus-fighting antibodies with no safety problems. In addition, the vaccine appeared 80% effective in preventing symptomatic COVID-19. But that calculation was based on just 10 cases diagnosed among study participants by the end of April, and it could change if more cases have occurred since.
Moderna’s study found tots ages 6 months through 5 years developed high antibody levels after two of its shots. But while there were no severe cases of COVID-19 during the trial, the vaccine was only about 40% to 50% effective at preventing milder infections.