Moderna to seek authorization of its coronavirus vaccine for young children
WASHINGTON — Moderna said Wednesday that it would seek emergency authorization of its coronavirus vaccine for children younger than 6, after interim results from its clinical trial showed that volunteers in that age group had a similar immune response to young adults when given a dose one-fourth as strong.
But the company said the vaccine proved only about 44% effective in preventing symptomatic illness among children 6 months to 2 years old, and 37% effective in children 2 through 5.
Dr. Jacqueline Miller, the firm’s senior vice president for infectious diseases, said the relatively low level of protection demonstrated the ability of the omicron variant to evade the vaccine’s shield. Nonetheless, she said, “what we have seen is a successful trial.”
“What I will say is 37.5% and 43.7% are higher than zero,” she said. “If I were the parent of a young child, I would want there to be some protection on board, especially if we see another wave of infections.”
Moderna’s findings about how well its vaccine works in the nation’s youngest children — the only Americans not yet eligible for shots — are bringing a question to the forefront: What level of effectiveness is good enough for a pediatric vaccine?
Just last month, Pfizer and its German partner, BioNTech, delayed seeking emergency authorization for their coronavirus vaccine in young children after data gathered during the omicron surge showed two doses were less than 50% effective against symptomatic disease, according to people familiar with the situation.
Whether the Food and Drug Administration, the Centers for Disease Control and Prevention, and the public will be willing to accept Moderna’s efficacy rate of about 40% on average for children under 6 is unclear.
While Americans have been hearing for months that the vaccines are less potent 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 for effectiveness against COVID-19. The guidance that the FDA initially set for adult coronavirus vaccines was at least 50% effectiveness against symptomatic infection.
All three authorized vaccines — from Moderna, Pfizer and Johnson & Johnson — vastly surpassed that at first. But omicron’s uncanny ability to dodge the immune system’s defenses is changing the calculus, and so far, no new standard has been set.
This article originally appeared in The New York Times.
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