As scientists race to answer crucial questions about the omicron variant of the coronavirus, many parents are wondering whether their children will need booster shots.
The Pfizer-BioNTech Covid-19 vaccine appears to be less effective against the omicron variant, according to early data from South Africa. On Wednesday, Pfizer and BioNTech announced that their own lab results also suggest the initial two-dose vaccine may be insufficient to prevent infection, though it may still protect against severe disease. A booster shot, however, does appear to provide strong protection against the omicron variant, the companies said.
When it comes to kids, though, several medical and vaccine experts say it is too soon to know whether they'll need booster shots. They also cautioned that the delta variant is still the dominant variant in the U.S.
"The hope is that because kids have a stronger immune response generally to the vaccine that, at least in the early going, after they've gotten the second dose, they should still be able to mount a pretty good vaccine immune response," said Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine and a co-director of the Texas Children's Hospital Center for Vaccine Development. "I think we still have a lot of unknowns, however. And whether or not a booster will be required could be something that's in the works. But that has got to be presented to the regulators before we know definitively. So we're not there yet."
The Food and Drug Administration authorized Pfizer's lower-dose Covid-19 vaccine for children ages 5 to 11 in October. Last month, the Centers for Disease Control and Prevention strengthened its recommendations about booster shots for adults, advising everyone over 18 to get a booster six months after their second Pfizer or Moderna shot or two months after their Johnson & Johnson vaccine.
Last week, Pfizer asked federal regulators to authorize a booster shot of its vaccine for 16- and 17-year-olds. Dr. Simon Li, director of the division of pediatric critical care at Rutgers Robert Wood Johnson Medical School in New Jersey and an associate professor of pediatrics at Rutgers University, said he expects a recommendation on that to come shortly, perhaps within the next two to three weeks. Li is a principal investigator in the Rutgers pediatric clinical trial for the Pfizer vaccine.
“It’s clear to anybody who understands this that having vaccination is a great methodology to prime and prevent serious infection,” Li said. “We know that for every variant that’s come out that’s been the case. And I would be shocked if that’s not the case for the omicron variant.”
During an appearance on CNN last month, Dr. Anthony Fauci, the government's top infectious disease expert, said it is possible that children ages 12 to 15 will need a booster shot, but he suggested it may not be necessary. Children in that age group have robust immune systems, Fauci said, adding that "healthy, strapping teenagers have a much better and stronger immune response" than older adults do. He said he would not be surprised if their vaccine protection lasts longer than six months.
Li said the vaccine trial results he has seen align with Fauci's assessment.
“That’s kind of what we’re seeing, actually, that the doses that you need to create a very strong immune response is much lower in children,” he said.
Hotez, meanwhile, said the biggest question about booster shots, regardless of a person's age, is how long and how durable the original vaccine's protection is. He also noted that the delta variant is still dominant in the U.S. and will likely remain so for at least the next couple of months.
Hotez added that it's not necessarily better to shorten the time window between a person's booster shot and their initial vaccine. Getting a booster too quickly, he said, may not result in as much of a boost.
"In other words, if you wait the six months, it might be a greater boost in virus neutralizing antibodies than if you did it after four months," he said.
That said, scientists are still trying to determine how dangerous the omicron variant is and what role booster shots could play in protecting people from it.
"We don't know yet exactly how virulent omicron is," Li said. "We know for a fact that it's very transmissible, so it's highly infectious."
Li said children in the Pfizer trial he is working on range in age from 6 months through 11 years old, and some of them are only now completing their second doses.
"So they haven't even gone to talk about boosters right now," Li said. "We're not there yet."