Pfizer says it will add third COVID vaccine shot to trials for young children

Company says two shots did not produce desired immune effect.
Doses of the Pfizer Covid-19 vaccine

Pharmaceutical companies Pfizer and BioNTech this week revealed that they would be adding a third COVID vaccine shot to trials for young children after the standard two-dose trial did not produce the desired immune effect in some trial participants.

The companys said in a Friday statement that, in a review of study data, the immune response benchmark “was met for the 6- to 24-month-old population but not for the 2- to under 5-year-old population.”

“The study will now include evaluating a third dose of 3 µg at least two months after the second dose of the two-dose series to provide high levels of protection in this young age group,” the statement said.

“Pfizer and BioNTech also plan to evaluate a third dose of the 10 µg formulation in children 5 to under 12 years of age,” the statement added. 

A two-shot vaccine has been the standard for much of the world over the past year, though officials have begun urging individuals to obtain a third “booster” shot in order to offer additional protection against SARS-CoV-2.