On Friday, Dec. 17, Pfizer/BioNTech Laboratories reported that the dose of its COVID-19 vaccine being administered to children aged two to five years old has not produced as strong an immune response as expected. 

 

Pfizer's head of vaccine research, Kathrin Jansen, said the company planned to apply for authorization to give a third dose of the vaccine to children, instead of the two doses originally planned. 

 

"If the revised strategy works, we would have a uniform three-dose vaccine approach for all ages," Jansen said on a conference call with investors and analysts on Friday, according to information disclosed by The New York Times.

The labs, which developed the COVID-19 messenger RNA vaccine, said they would now test a third low dose of the coronavirus vaccine in children aged six months to under five years old. They do not plan to test a higher dose of the vaccine in children between two and five years of age.

 

"The goal here is to understand the protective potential of the third dose," said Pfizer spokeswoman, Jerica Pitts.

 

The three-microgram dose used in minors did prove effective for children aged six months to two years old, as their immune response was similar to that of 16 to 25-year-olds. 

 

Currently, Pfizer/BioNTech is developing a trial with children under five years of age, who will receive three micrograms of the vaccine two months after their second dose. The labs also plan to evaluate a third dose of 10 micrograms, one-third of the adult dose, in children aged five to 12 years old.

 

These changes have already been approved by the Food and Drug Administration (FDA) and the European Medicines Agency (EMA), according to a statement released by the companies on Dec. 17.