Moderna aims to be the first with COVID vaccines for the youngest children

On Thursday, Moderna asked U.S. regulators to allow low doses of its COVID-19 vaccine for children under 6 years of age, a welcome step towards potentially opening vaccines to millions of toddlers by the summer.

Frustrated families are looking forward to the chance to protect the nation’s smallest children as everyone around them removes their masks and takes other public health precautions, even as highly contagious coronavirus mutants continue to spread.

Moderna has released data to the Food and Drug Administration that it hopes will prove that two low-dose shots can protect infants, toddlers and preschoolers, though not as effectively during an omicron surge as previously during pandemics.

“These youngest children have an important unmet medical need,” Dr. Paul Burton, Moderna’s chief medical officer, told The Associated Press. Two children’s shots “will protect them well. I think it is likely that over time they will need additional doses. But we are working on it.”

Only children aged 5 years and older can now be vaccinated in the US using the competing Pfizer vaccine, leaving 18 million toddlers unprotected.

Moderna’s vaccine isn’t the only one in the race. Pfizer is expected to announce soon whether three of its even smaller doses work for the youngest children, months after the disappointing discovery that two doses weren’t strong enough.

FDA head of vaccines Dr. Peter Marks said the agency will “act quickly without sacrificing our standards” in deciding whether doses for toddlers are safe and effective, whether one company’s vaccines or both.

While questions about what’s taking so long are swirling, Marks pointedly told lawmakers this week that the FDA can’t evaluate a product until the manufacturer fills out an application. The FDA will publicly discuss the evidence with its scientific advisors before making a decision, and Marks said several meetings will be scheduled to cover several expected applications.

“It’s critical that we have a proper assessment that parents have confidence in any vaccines we authorize,” Marks told the Senate committee.

If the FDA approves vaccines for toddlers, then the Centers for Disease Control and Prevention will have to recommend whether they should be given to all toddlers or only those who are at increased risk of contracting COVID-19.

Many parents are desperate for the vaccine that gets to the scientific end first.

“We’re sort of left behind as everyone else is leaving,” said Megan Dunphy-Daly, a Duke University marine biologist whose 6-year-old daughter is vaccinated, but whose 3-year-old and 18-month old sons are part of Pfizer’s trial.

The family continues to wear masks and take other precautions until it is clear whether the boys received the real vaccine or sham shots. Dunphy-Daly said if it turns out they weren’t protected in the Pfizer study and Moderna’s shots are cleared first, she will look for them for her sons.

“I will be so relieved to know that my boys are vaccinated and that the risk of being seriously infected by them is so low,” she said.

Some parents have even called on the government to allow families to choose vaccinations before all the evidence has been collected.

“This strain of COVID seems almost impossible to dodge,” tearfully told Dana Walker, mother of an 8-month-old, at a CDC meeting last week. “Stop the bureaucracy and let parents protect their children.”

The FDA will face some tough questions.

In a study of children aged 6 months to 5 years, two shots of Moderna — every quarter of the usual dose — elicited high levels of virus-fighting antibodies, the same amount has been shown to protect young adults, Burton said. There were no serious side effects, and the vaccines caused fewer fevers than other conventional vaccines.

But the effectiveness of the vaccine in preventing symptomatic COVID-19 during trials appeared to be about 40-50%. Burton blamed the omicron variant for being able to partially evade vaccine immunity, noting that unstimulated adults showed less efficacy against milder omicron infections. While no children became seriously ill during the study, he said that high antibody levels are a proxy for protection against more serious illnesses, and the company will test a booster dose for children.

Another problem: So far, in the US, the Moderna vaccine is for adults only. Other countries have expanded vaccination to children as young as 6 years of age. But a few months ago, the FDA raised concerns about a rare side effect of heart inflammation in teenage boys, and did not rule on Moderna’s earlier pediatric uses.

Burton said the FDA may consider its vaccine for children of all ages, but may also open it up first to the youngest children, who have no other choice. He said the safety data for the millions of older children who received the Moderna vaccine abroad should reassure parents.

Although COVID-19 is generally not as dangerous to children as it is to adults, some of them become seriously ill or even die. About 475 children under the age of 5 have died from COVID-19 since the start of the pandemic, according to the CDC, and hospital admissions for children have skyrocketed at the peak of omicron activity.

However, it is unclear how many parents intend to vaccinate their youngest children. Less than a third of children aged 5 to 11 received two shots, and 58% of children aged 12 to 17.