Coronavirus updates: Centers for Disease Control and Prevention (CDC) recommends two coronavirus vaccines for very young children

The Centers for Disease Control and Prevention on Saturday recommended Covid vaccines for children younger than 6 months old, who were among the last Americans to be eligible for vaccinations. Parents should be able to start immunizing young children as soon as Tuesday.

Federal regulators have now allowed the Moderna vaccine for children 6 months to 5 years old, and the Pfizer-BioNTech vaccine for children 6 months to 4 years old. (The Pfizer-BioNTech vaccine has been available for children 5 years of age and older since November.)

Dr. Rochelle B.

“Together, with the flag leading the reins, we took  Another important stepstraight aheadIn our nation’s fight against Covid-19. “We know that millions of parents and caregivers are eager to vaccinate their young children, and with today’s decision, they can.”   

After meetings on Friday and Saturday, the agency’s scientific advisors strongly supported the vaccines, despite reservations about the paucity of data, especially regarding the effectiveness of the Pfizer-BioNTech vaccine.

CDC . panel I heard the evidence Supporting the effectiveness of vaccines in younger children, but Pfizer has repeatedly pressed its estimates and indicated the need for three doses of this vaccine, compared to two doses of Moderna’s vaccine.

Both vaccines are safe, and both produce levels of antibodies similar to those seen in adults. But CDC advisors have had a hard time recommending two very different vaccines for the same population.

“Implementing these two propositions will be very challenging,” said Catelyn Getelina, a public health expert and author of the widely read newsletter.Your local epidemiologist. “

“There has to be 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 a quarter of the adult dose, produced levels of antibodies that were at least as high as those seen in adults.

The company estimated the vaccine’s effectiveness against symptomatic infection at about 51 percent among children ages 6 to 24 months, and 37 percent among children ages 2 to 5.

Side effects were minor, although about one in five children had a fever. Efficacy against severe illness and death is assumed to be higher, similar to effects seen in adults.

Based on this data, the Food and Drug Administration has authorized two doses of Moderna’s vaccine, four weeks apart.

The Pfizer-BioNTech vaccine also produced a strong immune response, but after only three doses, company officials told scientific advisors Friday.

And they said two doses of the vaccine were not enough — justifying the Food and Drug Administration’s decision in February to delay licensing the vaccine until regulators had data on three doses. Some consultants said the two doses might not be enough because the company gave children only one-tenth of the adult dose in each dose.

On Friday, Pfizer scientists claimed the vaccine has an overall efficacy of 80 percent in children under five. But this account was based on Centers for Disease Control and Prevention advisors note that only three children in the vaccine group and seven received a placebo, making it an unreliable measure.

“We should just assume we don’t have efficacy data,” said Dr. Sarah Long, an infectious disease expert at the Drexel University School of Medicine. But Dr. Long said she was “comfort enough” with the other data supporting the vaccine’s efficacy.

Three doses of Pfizer’s vaccine produced levels of antibodies similar to those seen in adults, indicating that it is likely to be just as effective.

“Pfizer is a three-dose series, but as a three-dose series, it’s very effective,” said Dr. William Towner, who led vaccine trials for both Moderna and Pfizer at Kaiser Permanente in Southern California.

Dr. Towner added that any vaccine would be better than none. He predicted that some parents might choose Moderna because it’s easier to get kids to the pediatrician for two drops than it is to arrange for them to get three.

The Pfizer vaccine was approved for children ages 5 to 11 in November, but fewer than 30 percent in that age group received two doses. In CDC surveys, about half of parents said in February they would vaccinate their children, but by May, only a third of parents said they intended to do so.

Advisers discussed whether vaccination enhances protection against severe disease in children who are already infected. There is little information available from children 5 to 11 years of age, due to poor uptake of vaccines in that age group.

But in adults, infection with the previous Omicron variant was not enough on its own to protect against later versions.

The experts concluded that vaccines will continue to be necessary to protect children from future changes. “This combined protection is really the safest and most effective,” said Dr. Sarah Oliver, the CDC scientist who led the discussion on Saturday.

Parents of young children may be more willing to opt for the Covid vaccine if it can be offered alongside other routine vaccinations, Dr. Towner said.

“This is the area that a lot of people don’t know about right now,” he said. “I hope there will be some guidance provided on that.”