Pfizer/BioNTech says a three-dose regimen of its COVID-19 vaccine appears to provoke a strong immune response in the youngest age group of children — those aged 6 months to 5 years.
This is the only age group not yet approved for COVID-19 vaccination by the U.S. Food and Drug Administration. According to CNN, Pfizer said it plans to submit its new data to the agency this week.
The phase 2/3 trial involved almost 1,700 children who received a third child-sized dose of the vaccine during a time when the Omicron variant was dominant. Tests conducted a month afterwards showed an antibody response that was similar to that seen in 16- to 25-year-olds who got two doses of vaccine, CNN reported.
Midway through the trial, the third dose gave the young children an 80% protection against asymptomatic COVID-19. The researchers spotted 10 symptomatic cases of COVID-19 arising at least seven days after the third dose. But the Pfizer team stressed that their analysis can’t be completed until at least 21 symptomatic cases arise in the vaccinated group and then compared to the number of symptomatic cases in the non-vaccinated group.
There appeared to be no safety issues with the vaccine, which was well-tolerated by the children.
The vaccine doses were adjusted downwards for these smallest kids — three 3-microgram doses for kids aged 6 months to 5 years. That’s compared to two 10-microgram doses for kids aged 5 to 12 and two 30-microgram doses for people 12 and older.
Kids in the youngest age group get the first two doses three weeks apart, and a third dose two months later.
The results of the new trial have been long anticipated. Immune response in young children was disappointingly low after two doses of the Pfizer vaccine, so the company said it would see how a third dose fared.
According to CNN, the FDA’s Vaccines and Related Biological Products Advisory Committee has meetings tentatively scheduled for June 8, 21 and 22 to discuss emergency use authorizations updates that could make kids in the youngest age group eligible for vaccination with the Moderna or Pfizer/BioNTech vaccines.
There’s more on vaccination against COVID-19 at the CDC.