“These data show that you can safely and effectively increase your antibody levels,” Dr. Paul Burton, Moderna’s chief medical officer, said in an interview. He expects those antibody levels to “translate into reduction in hospitalization, reduction in severe COVID, and reduction in long COVID.”
But that good news is clouded by questions about how useful the shots will be at this point in the pandemic.
Earlier this week, the Centers for Disease Control and Prevention estimated that 75 percent of children ages 11 and younger have already been infected, giving them at least some immunity to the virus and making authorization of the vaccines for the youngest less urgent in the eyes of some doctors. Moreover, Dr. Anthony Fauci, the nation’s top infectious disease expert, said the country is now out of the “acute component of the pandemic phase.”
“I think most people would agree that it is no longer an emergency,” said Dr. H. Cody Meissner, chief of Pediatric Infectious Disease at Tufts University School of Medicine.
He also noted the trials by Moderna, and separately, Pfizer, are so small that the companies cannot determine the risks of rare side effects or definitively provide the vaccines reduce the chance of hospitalization and death.
Meissner himself will have to make that calculation, since he serves on the FDA’s vaccine advisory committee that is expected to review the Moderna submission.
“In this case the benefit is very, very small, but the risk from the vaccine is also very, very small. So it becomes more about how does a parent feel about it,” Meissner said. For now, Meissner would only recommend vaccinating young children if they have a condition that puts them at risk of severe COVID, or if “the parent is so anxious they can’t sleep at night.”
Moreover, the effectiveness of vaccines has been somewhat undermined by the virus’s constant evolution into new strains that are different from what the shots were originally designed to combat. Still, data show the vaccines continue to protect against most cases of severe disease, hospitalization, and death, especially with a booster.
Burton said the protection levels against infection in young kids “is fully consistent with what we see in adults” who have had two shots of an mRNA vaccine. Moderna said it plans to study booster shots in young children, too.
Throughout most of the pandemic, children have been far less likely to be hospitalized with COVID than adults. According to the CDCabout 3 out of 100,000 children 4 and younger were hospitalized with COVID during the Delta surge last September.
But during the Omicron surge, which started in December, the risk of a child 4 and younger being hospitalized with COVID grew fivefold.
And, given the hospitalization rates of older, unvaccinated children who got COVID, John L. Sullivan, a co-investigator of the Moderna trial at the UMass Chan Medical School, urged the FDA to approve the company’s application for the younger cohort.
“We know if one looks at the hospitalization data from the kids 5-12 years old, the majority of those kids that end up in the hospital and ICU are kids that haven’t received the vaccine,” he said
At a briefing Tuesday, CDC epidemiologist Dr. Kristie Clarke said 20 to 30 percent of children hospitalized with COVID-19 end up being admitted to the ICU, and that Multisystem Inflammatory Syndrome, which can follow cases of COVID, mostly strikes previously healthy children. She said evidence shows that vaccination can help protect against those outcomes and can broaden and strengthen natural immunity from previous infections.
And, Dr. Kristin Moffitt, a pediatrician at Boston Children’s Hospital who specializes in infectious diseases, noted there could be rebounds in COVID transmission when the cold weather returns.
“I think that taking the urgency out of vaccinations for young children because things feel kind of OK right now would be very short-sighted,” she added. “I don’t think they should just be offered, I think they should be encouraged.”
Many parents interviewed Thursday said they were thrilled that a vaccine for their younger children may finally be within reach.
Molly Pipp, who lives in Braintree, said her 5-year-old son is vaccinated and she expects her 3-year-old daughter to be as well when it becomes available.
“I’ll want to know that it’s safe, but there is just too much stuff out there about unknown side effects when it comes to COVID,” Pipp said. “The side effects for the vaccination, we know most of them. To me, the risk of vaccination is less than the risk of nonvaccination.”
Samantha Dotterweich, who lives in South Boston, said she hopes to vaccinate her 4-year-old daughter and almost 2-year-old sons when one becomes available.
“My approach is to get my kids vaccinated with whatever our pediatrician recommends,” she said.
So far, parents of younger children have not turned out in large numbers to vaccinate their children. According to state data, only 56 percent of children ages 5 to 11 in Massachusetts have received at least one dose of a COVID vaccine — a much lower rate than for other age groups in the state.
However, those numbers are better than the national average, where only 35 percent of children ages 5 to 11 have received at least one dose of the vaccine.
Even for parents eager to vaccinate, it remains unclear how much longer they will have to wait before the shots are authorized. Moderna must finish its application to the FDA, which the company said it expects to complete next week.
The FDA usually agrees to a meeting of a vaccine advisory committee of outside experts that recommends whether the agency should authorize the shots. A source with knowledge of the advisory committee’s calendar said the earliest meeting time may not be until June. Some experts have speculated that the FDA is waiting until June so that it can weigh Moderna’s data and Pfizer’s data together.
Pfizer has said it expects to submit its vaccine application for babies and toddlers this quarter.
Dr. Paul A. Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, who is on the FDA’s vaccine advisory panel, said it is likely the committee will meet in June.
Among the areas that Offit expects the committee to review is safety data, a critical component since severe disease is less likely in young children. Given that only 6,700 children were involved in the Moderna trial, and severe disease is uncommon, there wouldn’t be enough robust data to definitively say the vaccine protects against severe disease, he said.
Dr. Brian Chow, an infectious disease physician at Tufts Medical Center who participated in Moderna’s clinical trial for this age range, said it has taken this long because scientists wanted a clear picture of the risks to adults first before trials proceeded on younger patients.