The Moderna vaccine for coronavirus is proving a strong immune response in children aged 6 to 11, researchers reported Wednesday – another sign in what has been a long and painful road to protecting young children from the virus, even if the case is still high.
On Monday, Moderna applied for permission from the Food and Drug Administration for vaccine use in this age group. But consent, if granted, is unlikely to increase immunization rates among young children significantly.
The Pfizer-BioNTech vaccine has been available to children aged 5 to 11 since November, but as of Wednesday, only 28.7 percent had received two doses. No coronavirus vaccine is available at all for children under 5 years of age, forcing parents to rely on non-invasive preventive measures.
Last month, Moderna asked the FDA to approve its vaccine for children 6 months to 6 years. The agency is already reviewing the company’s data on teens, and is expected to decide on the use of the Moderna vaccine for children of all ages in June.
In February, Pfizer and BioNTech also sought approval for their vaccine for more infants, but withdrew the request after data suggested that the two doses did not provide adequate protection against the Omicron variant.
The companies are setting up banks in a third dose to strengthen immunity in children, and the FDA is expected to review the data in June as well.
“We really can’t do it this way in the future – we can’t leave the kids to the very end,” said Dr. Sallie Permar, a pediatric immunologist at Weill Cornell Medicine in New York.
The process has been confusing and unfair to parents of the youngest infants, who have not been vaccinated for more than two years in this epidemic, he said.
It has been almost a year since Moderna applied for FDA approval for the use of its vaccine for 12- to 17-year-olds. of Moderna was stuck.
Authorization delays have been the longest in the United States. Drug regulators in Europe approved the Moderna vaccine for 12- to 17-year-olds last summer, and have recommended approval for children ages 6 to 11.
Regulatory organizations in Canada and Australia have also approved the Modern vaccine for children aged 6 to 11 years.
In the United States, more than one in four children out of 28 million aged 5 to 11 have been vaccinated against the corona virus. Parental reluctance seems to stem from the fact that the infection is known to be less dangerous for children.
“The risk of a child getting severe Covid is high, very low – let’s be honest about it,” said Dr. Ofer Levy, director of precision immunization program at Boston Children’s Hospital and FDA consultant.
Still, he said he had treated a child with leukemia who had been hospitalized for Covid. “Some children get bad Covid, others end up in hospital,” he said, adding that more than 1,500 children under the age of 18 have died so far in the epidemic.
“I’m not in authority, but I think families should have the option to protect their little one,” he said. Levy said.
In her trial, published in the New England Journal of Medicine, Moderna first tested different doses of her vaccine and selected a dose of 50 microns – half the dose for adults – for children ages 6 to 11. Then the researchers plotted more randomly. of 4,000 children. received two bullets for 28 different days.
Three-quarters of the children were vaccinated, and the rest received placebo bullet salts. About half of the children came from racial backgrounds. To test the strength of the vaccine, the researchers tested the antibodies provided after the vaccine. (Pfizer vaccine trials were based on this same technique, called immunobridging.)
Children who received the vaccine gave antibodies that were slightly higher than those seen in adolescents, a sign of hope. The trials were not large enough to evaluate the effectiveness of the vaccine to prevent serious illness or death.
But based on the small number of infections and the Delta variant among participants, the researchers estimated that the vaccine was 88 percent effective against infections.
“Immunobridging is basically an educated assumption that we take – that the same level of immunity will only be immune in the younger age group as it was in the older group,” Drs. Permar said. “So it’s good when you can also follow that effectively.”
The bullets appeared to provide only a small effect – including pain at the injection site, headache and fatigue – and less often than in adults. About half of the children also had a fever, for one day.
The effect can be problematic for children under the age of 5, because high fever in very young children requires invasive tests to prevent the spread of harmful bacteria, Dr. Permar said.
The trial was not large enough to detect adverse effects, such as heart problems that were observed in other age groups. The Pfizer-BioNTech vaccine appears to cause fewer cases of so-called myocarditis among young children than among adolescents or young adults.
Moderna’s trial tested the strength of the vaccine against the Delta variant, and researchers are still evaluating its performance against Omicron. All vaccines have been proven to be relatively effective, in all age groups, against the Omicron variant.
Independent scientists have reported that the Moderna vaccine causes a strong immune response in children aged 7 to 11, and in adolescents, against the variant Omicron and other versions of coronavirus.
But these antibodies appear to decrease over time, as they do in adults. “Perhaps vaccine performance, in terms of vaccine effectiveness, will not be as high in real-world data,” Drs. Levy said.
Dr. Permar said he hopes the epidemic will make a difference in how vaccines are evaluated in an emergency.
“We need to think of different ways to deal with it, including children and pregnant women in early trials,” she said. “And we need to do it now, because the next catastrophe will befall us before we want it to be.”