Modern Corona virus vaccine stimulates strong immune response in children aged 6 to 11, researchers report Wednesday , Even things are going up again.
On Monday, Moderna requested permission from the Food and Drug Administration to use the vaccine in this age group. But if allowed, the immunization rate for young children is unlikely to increase significantly.
The Pfizer-BioNTech vaccine has been available for children ages 5 to 11 since November, but as of Wednesday, only 28.7% had received two doses. There is no coronavirus vaccine available for children under 5, forcing parents to rely on less reliable safety measures.
Last month, Moderna asked the FDA to allow its vaccine to be used in children aged 6 months to 6 years. The agency is already reviewing the company’s data on adolescents, and is expected to make a decision in June on the use of the modern vaccine in children of all ages.
In February, Pfizer and BioNTech also sought permission for their vaccine to be used in the youngest children, but withdrew the request after data suggested that the two doses did not provide adequate protection against the Omicron variant.
Companies are banking on a third dose to boost children’s immunity, and the FDA is expected to review the data in June.
“We can’t really do that in the future – we can’t leave children until the last minute,” said Dr. Sally Parmar, a pediatric vaccine specialist at Well Cornell Medicine in New York.
He said the practice has been particularly confusing and unfair for parents of the youngest children, who have not had access to the vaccine for more than two years due to the epidemic.
It has been almost a year since Moderna applied for FDA permission to use her vaccine in 12- to 17-year-olds. While the agency allowed the Pfizer-BioNTech vaccine to be used in this age group in just three weeks, the agency stopped reviewing the Moderna vaccine.
Delays in permitting have been the longest in the United States. European drug regulators last summer approved the Moderna vaccine for adolescents between the ages of 12 and 17, and recommended approval for children aged 6 to 11.
Regulatory agencies in Canada and Australia have also approved the Moderna vaccine for children aged 6 to 11.
In the United States, only one in four of the 28 million children between the ages of 5 and 11 have been vaccinated against the corona virus. Parental reluctance is partly due to the fact that the infection is less dangerous for children.
Dr. Afar Levy, director of the health vaccine program at Boston Children’s Hospital and an adviser to the FDA, said, “The risk of a child becoming severely infected is very, very, very low – let’s be honest about that.”
However, he said he had just treated a child with leukemia who had been hospitalized for covid. “Some children get severe colic, some go to the hospital,” he said, adding that more than 1,500 children under the age of 18 have died of the disease so far.
“I’m not in the mandate, but I think families should have the option of protecting their youngest,” said Dr. Levy.
In her trial, published in the New England Journal of Medicine, Moderna first tested different doses of her vaccine and chose a half-dose of 50 micrograms – the adult dose for children aged 6 to 11. To get two shots at a distance of 28 days.
Three-quarters of children were vaccinated, and the rest received saltwater placebo shots. About half of the children were from colorful communities. To assess the potency of the vaccine, researchers measured antibodies produced after immunizations. (Pfizer vaccine trials rely on the same approach, called immunogenicity.)
Children who received the vaccine developed antibody levels that were slightly higher than those seen in adolescents, which is a promising sign. The trials were not large enough to assess the vaccine’s ability to prevent serious illness or death.
But based on the small number of delta-type infections in the participants, the researchers estimated that the vaccine’s effectiveness against the infection was 88%.
“Immuno-bridging is basically an educated assessment that we take – that the same level of immunity in a younger age group will be as protective as in the older age group,” said Dr. Parmar. “So it’s good when you can follow it with utility.”
Shots seem to produce only minor side effects – including pain, headache and fatigue at the injection site – and less frequently than in adults. About half of the children also had a fever for about a day.
Dr. Parmar said that this side effect can be a problem in children under 5 years of age, as very young children need an invasive test to rule out a dangerous bacterial infection for high fever.
The trial was not large enough to detect rare side effects, such as heart problems seen in other age groups. The Pfizer-BioNTech vaccine causes fewer cases of so-called myocarditis in young children than in adolescents or young adults.
Moderna’s trial measured the potency of the vaccine against the Delta variant, and researchers are still evaluating its effectiveness against Omicron. All vaccines have been shown to be less effective against different types of Omicron in all age groups.
Independent scientists report that the modern vaccine stimulates a strong immune response in children and adolescents between the ages of 7 and 11 against the Omekron variant and other versions of the corona virus.
But these antibodies appear to decrease over time, as they do in adults. “Vaccine performance may not be as high in real-world statistics as vaccine efficacy,” said Dr. Levy.
Dr Parmar said he hoped the epidemic would change the way vaccines are tested during emergencies.
“We need to think of a different way to include children and pregnant women in the first trials,” she said. “And we need to do that now, because the next epidemic is about to hit us before we want to.”