Albert Bourla, president and chief executive officer of Pfizer, said in a statement that “ultimately, we believe that three doses of vaccine for children aged 6 months to 4 years will be needed to achieve levels of protection. highly protected against current and potential future variations. But he said that if two doses are allowed in the meantime, “parents will have the opportunity to start a series of Covid-19 vaccinations for their child while awaiting the potential authorization of the dose.” Tuesday.”
The Pfizer and BioNTech study of younger children was aimed at measuring immune responses, not the effectiveness of vaccines in preventing infection or severe cases of Covid-19. But because some of the children in the trial were infected, the researchers had an indication of how well the vaccine was working to suppress the virus, two people familiar with the study said. A similar development has occurred in the companies’ research into their vaccines for 5- to 11-year-olds, coinciding with the Delta variant crush wave.
A person familiar with the data who spoke on condition of anonymity said that 2- to 4-year-olds who received two shots were infected at a 57% lower rate than children in the placebo group. Children 6 months to 2 years of age who were vaccinated became infected at a 50% lower rate than the placebo group. There were less than 100 symptomatic infections – a small fraction of the total number of participants – and the error rate was huge, the person said.
The data also suggest that the vaccine protects children against infection from Delta better than Omicron. Omicron was better than Delta at evading the protection of both Pfizer-BioNTech and Moderna vaccines in adults.
Regulators’ strategy appears to be based in part on the ability of Pfizer-BioNTech’s three-dose trial to prove successful. Several experts, including Dr. Yvonne Maldonado, professor of pediatric infectious diseases at Stanford, say the history of vaccines suggests that the third dose will in fact enhance the immune response.
“There is almost no hypothesis that the third dose will be worse,” said Dr Maldonado, principal investigator at Stanford of Pfizer-BioNTech’s pediatric vaccine trial. “At worst, it couldn’t be otherwise. So maybe just two doses is the best dose you’ll get. “
Dr. H. Cody Meissner, another member of the FDA advisory committee and chief of the pediatric infectious disease division at Tufts Children’s Hospital, said he’s very open about the FDA’s approach. But he said he was worried about whether rare side effects might be missed in small-scale trials. The Pfizer-BioNTech trial included about 1,200 children younger than 2 years old and about 1,500 children 2 to 4 years old, according to people familiar with the study’s design.
https://www.nytimes.com/2022/02/01/us/politics/pfizer-vaccine-kids.html Pfizer asks FDA to remove 2 doses of childhood vaccine at the start