Moderna to Seek Authorization of Its Coronavirus Vaccine for Young Children

WASHINGTON. On Wednesday, Moderna said it would seek emergency authorization for its coronavirus vaccine for children under six years of age after interim results from its clinical trials showed that volunteers in that age group had a similar immune response to younger adults when given a dose of one to four strength.

But the company said the vaccine was only about 44% effective in preventing symptomatic illness in children aged six months to 2 years and 37% in children aged 2 to 5 years.

Dr. Jacqueline Miller

 Dr. Jacqueline Miller, the company’s senior vice president of infectious diseases, said the relatively low level of protection demonstrated. However, she said in an interview, “what we’ve seen is a successful test.”

“I will say 37.5% and 43.7% are above zero,” she said. “If I were a parent of a small child, I would like to have some sort of protection on board. Especially if we see a new wave of infections.”

The firm’s announcement comes as the Biden administration’s efforts to protect people from the ever-mutating virus enter a new period of change. Officials are arguing over whether to offer a second booster shot this spring to at least the oldest Americans. Meanwhile, various studies are looking to determine if existing vaccines can be reconfigured to provide more excellent protection against Omicron. A sub-variant of the virus known as BA.2.

Now, Moderna’s findings of how well its vaccine works in the nation’s most minor children — the only Americans not yet allowed to get vaccinated — bring another question: what level of effectiveness is sufficient for a pediatric vaccine?

Last month, Pfizer and its German partner BioNTech delayed an emergency approval for a coronavirus vaccine in young children after data collected during the Omicron surge showed two doses were less than 50 percent effective against the symptomatic disease. According to people familiar with the situation.

The Food and Drug Administration

It’s unclear whether the Food and Drug Administration, the Centers for Disease Control and Prevention and the public will be willing to accept Moderna’s success rate of about 40 percent on average for children under six years of age.

Although Americans have heard for months that vaccines are less effective against Omicron in all age groups, neither Moderna’s nor Pfizer’s results in young children meet what many vaccine experts consider the minimum standard of effectiveness against Covid-19. The FDA initially set guidance for coronavirus vaccines for adults was that it was at least 50 percent effective against symptomatic infection.

All three approved vaccines—from Moderna, Pfizer, and Johnson & Johnson—significantly outperformed that figure at first. But Omicron’s uncanny ability to evade immune system defenses changes the calculus, and no new standard has been set.

FDA approved the Pfizer-BioNTech vaccine

The FDA approved the Pfizer-BioNTech vaccine for children aged 12 to 15 in May after a trial showed no infections in the vaccine group and 18 cases in the placebo group, a ratio that Pfizer describes as 100 percent effective. But in October, when the agency approved Pfizer’s vaccine for children aged 5 to 11. It relied solely on immune response data, which showed the vaccine caused a massive antibody spike. This was also the criterion set for testing young children.

Given the antibody response, regulators were unwilling to wait for enough Covid infections to build up in enough trial participants to evaluate efficacy. But as the Omicron variant spread to a large population over the winter. Both Moderna and Pfizer can now assess the performance of their youngest trial participants.

Last month, Pfizer decided to delay its two-dose emergency authorization request after seeing Omicron’s efficacy data.

Updated 

March 23, 2022, 4:30 pm ET

Moderna is asking for a similar permit, citing equally weak performance data. On the other hand, Moderna’s two-dose regimen has shown better results than Pfizer’s in boosting the immune systems of young children. In December, Pfizer said that after two doses of the vaccine, children aged six months to 2 years produced antibodies comparable to older teens and young adults.

But children between the ages of 2 and 4 produced only 60 percent of the desired antibody response. After two doses of the Moderna vaccine, the antibody response in children in both subgroups was better than that in people aged 18 to 25 years, meeting the primary criterion for trial success.

“I am encouraged by the strong neutralizing antibody response indicating long-term cellular immunity,” said Dr. Monica Gandy, infectious disease physician and professor of medicine at the University of California, San Francisco.

Dr.Anthony S. Fauci

At a briefing on Wednesday, Dr. Anthony S. Fauci, the White House’s chief medical adviser, said that the Moderna shot is safe for young children. While the level of effectiveness “may seem like a low number,” he said, “in the Omicron era. It’s comparable to the effectiveness against infection that we’re seeing now with other vaccines.”

“So the data looks pretty good right now,” he said.

Pfizer’s three-dose vaccine before authorizing either vaccine. Pfizer said it would have data on how well the three doses work in early April. This may allow the FDA to compare the results of Moderna’s two-dose vaccine.

Nearly two-thirds of the US population, or more than 217 million people, are fully vaccinated. About half of those who qualify for a booster have received it. But progress among children has slowed, with only one in four children fully vaccinated between the ages of 5 and 11.

Pfizer-BioNTech vaccine

So far, the Pfizer-BioNTech vaccine has been the only vaccine approved for children aged 5 to 18. But Stephane Bancel, Moderna’s chief executive, said on Wednesday that the company would also ask for emergency approval to vaccinate children aged 6 to 11. It will update a similar request filed last year for those aged 12 to 17.

This request was held because the FDA wanted more data on myocarditis’s rare side effects. It is associated with inflammation of the heart. Moderna says those concerns have now subsided, and at least some federal health officials agree.

Regulators generally do not skip age groups when authorizing vaccines. So the FDA may consider whether to approve Moderna vaccines for infants and adolescents simultaneously.

Approximately 6,900 children in the United States and Canada were included in the Moderna study for children under 6. Most of the infections in the experimental group were mild. Moderna said there were no severe illness, hospitalization, or death cases.

Dr. Miller

Dr. Miller said Moderna is looking into whether a booster shot might be needed for everyone under 18. “We certainly intend to give a booster dose to these children,” she said.

The majority of adverse events in volunteers were mild to moderate, and fever rates were typical of existing pediatric vaccines. Fourteen children — 0.2 percent of the study group — developed fevers above 104 degrees, the firm says.

Young children do not usually get seriously ill from Covid. But according to one data set published by the CDC, 355 children under 5 in the US have died from Covid since the start of the pandemic. CDC officials say the data is the most reliable because it is based on death certificates; other scores are higher.

There is a need to protect the youngest children. Especially as more countries unmask, more parents return to work, and more normal lives resume.

Dr. Caitlin Elgarten

In Moderna’s study, Dr. Caitlin Elgarten, a Philadelphia pediatrician, included her 2-year-old son and 4-year-old daughter. The doctor was looking forward to the results.

She said she was concerned about the possibility of prolonged Covid, with its lasting health consequences, if her children got sick. She also noted that the 10-day quarantine that many kindergartens enforce on infected children “is a huge burden on lives and families.”

“It seems like the world is moving forward,” she said, “and we have to either just take the risk or keep limiting ourselves when no one else is.”