The Centers for Disease Control and Prevention on Saturday recommended Covid vaccines for children as young as 6 months old, who were among the last Americans to qualify for vaccines. Parents should be able to start vaccinating their young children as early as Tuesday.
Federal regulators have now authorized the Moderna vaccine for children ages 6 months to 5 years and the Pfizer-BioNTech vaccine for children ages 6 months to 4 years. (Pfizer-BioNTech’s vaccine has been available for children ages 5 and older since November.)
All children 6 months and older, including those who have already been infected with the coronavirus, should receive a Covid vaccine, CDC director Dr. Rochelle P. Walensky said in a statement.
“Together, with science leading the charge, we took another important stepforwardin our country’s fight against Covid-19,” she said. “We know millions of parents and caregivers are eager to get their young children vaccinated, and with today’s decision, they can.”
Following meetings on Friday and Saturday, the agency’s scientific advisers strongly supported the vaccines, despite reservations about the lack of data, particularly regarding the effectiveness of the Pfizer-BioNTech vaccine.
The CDC panel heard evidence supporting the vaccines’ effectiveness in younger children, but repeatedly pressed Pfizer on its estimates and noted that three doses of this vaccine would be needed, compared to two doses of the Moderna vaccine.
Both vaccines are safe and both produced antibody levels similar to those seen in young adults. But CDC advisers have struggled with the difficulty of recommending two very different vaccines for the same population.
“Implementing these two deployments is going to be incredibly difficult,” said Katelyn Jetelina, public health expert and author of the widely read “Your Local Epidemiologist” newsletter.
“It’s going to take a lot of proactive communication about the difference between the two and the implications of taking one over the other,” she said.
In its clinical trials, Moderna found that two shots of its vaccine, each with a quarter of the adult dose, produced antibody levels at least as high as those seen in young adults.
The company estimated the vaccine’s effectiveness against symptomatic infection at around 51% in children aged 6 to 24 months and 37% in children aged 2 to 5 years.
Side effects were minor, although around one in five children had a fever. Efficacy against severe illness and death is thought to be higher, similar to effects seen in adults.
Based on this data, the FDA authorized two injections of the Moderna vaccine, spaced four weeks apart.
The Pfizer-BioNTech vaccine also produced a strong immune response, but only after three doses, company officials told scientific advisers on Friday.
Two doses of the vaccine were insufficient, they said – justifying the FDA’s decision in February to delay licensing the vaccine until regulators had data on three doses. Two doses may not have been enough, as the company only gave children a tenth of the adult dose with each injection, some advisers said.
The vaccine has an overall effectiveness of 80% in children under 5, Pfizer scientists said on Friday. But that calculation was based on just three children in the vaccinated group and seven who received a placebo, making it an unreliable measure, CDC advisers noted.
“We should just assume that we don’t have efficacy data,” said Dr. Sarah Long, an infectious disease expert at Drexel University College of Medicine. But Dr Long said she was “quite comfortable” with other data supporting the potency of the vaccine.
Three doses of the Pfizer vaccine produced antibody levels comparable to those seen in young adults, suggesting it is likely to be just as effective.
“The Pfizer is a three-dose series, but as a three-dose series it’s quite effective,” said Dr. William Towner, who led vaccine trials for Moderna and Pfizer at Kaiser Permanente in California from South.
Either vaccine would be better than none, Dr Towner added. He predicted that some parents might opt for Moderna because it’s easier to take children to a pediatrician for two injections than to arrange for them to get three.
The Pfizer vaccine was licensed for children ages 5 to 11 in November, but less than 30% of that age group have received two shots. In surveys conducted by the CDC, about half of parents said in February they would vaccinate their children, but in May only a third of parents said they intended to do so.
Advisors have debated whether vaccination improves protection against serious diseases in children who have already been infected. There is little information available on children aged 5-11 years, due to low vaccine coverage in this age group.
But in adults, infection with the earlier variant of Omicron alone was not enough to protect against the newer versions.
Vaccinations would still be needed to protect children from future variants, the experts concluded. “This combination protection is really the safest and most effective,” said Dr. Sara Oliver, a CDC scientist who led the discussion on Saturday.
Parents of younger children may be more willing to opt for a Covid vaccine if it can be offered alongside other routine vaccinations, Dr Towner said.
“That’s the area that a lot of people are unsure about right now,” he said. “Hopefully there will be guidance on this.”