Health Care

Pfizer says booster in kids 5-11 produces ‘high’ immune response

Oliver Estrada, 5, receives the first dose of the Pfizer COVID-19 vaccine at an Adelante Healthcare community vaccine clinic at Joseph Zito Elementary School, Saturday, Nov. 6, 2021, in Phoenix. This was the first time children aged 5 to 11 across the United States had the opportunity to get immunized against COVID-19. (AP Photo/Ross D. Franklin)

Pfizer and BioNTech said Thursday that a third dose of their COVID-19 vaccine in children ages 5 to 11 produced a “high” immune response, and that they will apply for authorization for a booster dose in the age group soon.  

Pfizer said in a news release that a third dose of the vaccine in those 5 to 11 produced a 36-fold increase in levels of neutralizing antibodies against the omicron variant, compared to two doses.  

Antibody levels against the original version of the virus increased by six-fold.  

“These data reinforce the potential function of a third dose of the vaccine in maintaining high levels of protection against the virus in this age group,” Pfizer said.  

The company plans to submit a request to the Food and Drug Administration for authorization for a booster dose in children 5 to 11 “in the coming days.” 


News of a possible booster for children 5 to 11 comes as there are still no doses at all authorized for children under five, though Pfizer has previously said it expects results in April from trials for that age group.  

The booster dose for children 5 to 11 “was well tolerated with no new safety signals observed,” Pfizer said.

While a booster dose for children 5 to 11 could bolster protection, there is a question of how many parents will take advantage of it for their children. Uptake of the initial shots in children has been slow, with just 28 percent of children 5 to 11 fully vaccinated, according to Centers for Disease Control and Prevention data.

“Clinical and real-world data continue to prove that a COVID-19 vaccine booster dose can keep individuals protected against severe disease,” Pfizer CEO Albert Bourla tweeted Thursday. “We now have new, positive data in children 5 to 11 that show high immune response following a booster.” 

Adults are already recommended to get a third shot, and people over 50 are now eligible for a fourth shot.