A Phase 2/3 trial of Pfizer/BioNTech’s two-dose Covid-19 vaccine for children ages 5 to 11 showed it is safe and generated a “robust” antibody response, Pfizer said in a news release on Monday.
These are the first such results released for a US Covid-19 vaccine in this age group, and the data has not yet been peer-reviewed or published. Pfizer said it plans to submit to the US Food and Drug Administration for emergency use authorization soon.
The trial, which included 2,268 participants ages 5 to 11, used a two-dose regimen of the vaccine administered 21 days apart. This trial used a 10 microgram dose – smaller than the 30 microgram dose that has been administered to people 12 and older.
“The 10 microgram dose was carefully selected as the preferred dose for safety, tolerability and immunogenicity in children 5 to 11 years of age,” Pfizer said.
Participants’ immune responses were measured by looking at neutralizing antibody levels in their blood and comparing those levels to a control group of 16- to 25-year-olds who were given a two-dose regimen with the larger 30 microgram dose. Pfizer said the levels compared well with older people who received the larger dose, demonstrating a “strong immune response in this cohort of children one month after the second dose.”
“Further, the COVID-19 vaccine was well tolerated, with side effects generally comparable to those observed in participants 16 to 25 years of age,” the company said. A Pfizer spokesperson also confirmed that were no instances of myocarditis, a type of heart inflammation that has been linked with mRNA vaccines.
Pfizer said these data will be included in a “near-term submission” for EUA and the companies will continue to accumulate the data needed to file for full FDA approval for people ages 5 to 11. The vaccine is currently approved for people age 16 and older. It is authorized for emergency use for people ages 12 to 15.
Pfizer said it is expecting trial data for children as young as six months “as soon as the fourth quarter of this year.”
“Since July, pediatric cases of COVID-19 have risen by about 240 percent in the U.S. – underscoring the public health need for vaccination. These trial results provide a strong foundation for seeking authorization of our vaccine for children 5 to 11 years old, and we plan to submit them to the FDA and other regulators with urgency," Albert Bourla, chair and chief executive officer of Pfizer, said in the statement.