5:26 p.m. ET, December 17, 2021
Pfizer will test third Covid-19 vaccine dose in children under 16
From CNN's Virginia Langmaid
A health worker prepares to administer a dose of Pfizer covid-19 vaccine at the Sanford Civic Center in Sanford, Florida, in early December.
(Paul Hennessy/SOPA Images/LightRocket/Getty Images)
Pfizer is including a third dose of its Covid-19 vaccine in trials of the vaccine in children under 16, the company announced Friday.
The company announced in an earnings call that it will be testing a three-microgram third dose in children younger than 5, and in a news release said it plans to test a 10-microgram third dose in children ages 5 to 11.
Pfizer said two doses of vaccine did not produce the hoped-for results in the children ages 2 to 5.
The vaccines protected the youngest group – infants and toddlers up to 2 years – at the same levels seen in teens and young adults, but the three-microgram dose did not produce the same immunity in the 2-to-5-year-olds, the company said in a news release.
“The decision to evaluate a third dose of 3 microgram for children 6 months to under 5 years of age reflects the companies’ commitment to carefully select the right dose to maximize the risk-benefit profile,” the company said.
An additional study, in adolescents 12 to 17 years old, will examine the use of a third dose of either 10 or 30 micrograms, the company said.
In the United States, a booster dose of Pfizer’s vaccine is currently for fully vaccinated people age 16 and older.
“The effectiveness data for three doses of the vaccine in general for people 16 years and older and the early laboratory data we have seen with Delta and other variants of concern, including Omicron suggests that people vaccinated with three doses of our Covid vaccine may have a higher degree of protection,” Kathrin Jansen, head of research and development at Pfizer, said in the call.
“Therefore, we have decided to modify each of the pediatric studies to incorporate a third dose to the series and seek licensure for a three dose series rather than a two dose series as originally anticipated.”
Pfizer is currently studying its vaccine in children 6 months to 2 years old and 2 to less than 5 years old. Jansen said in an earlier phase of the trials for the primary series, a 3-microgram dose in the 2- to 5-year-old cohort showed comparable immune response to dosages given to older populations with fewer side effects than a 10-microgram dose.
Jansen said the change in the trials is not expected to impact the timeline to submit for emergency use authorization for the vaccine in younger populations, which is still targeted at mid-2022.
“If the three-dose study is successful, Pfizer and BioNTech expect to submit data to regulators to support an Emergency Use Authorization (EUA) for children 6 months to under 5 years of age in the first half of 2022.”