Pfizer and BioNTech announced Thursday that they are testing a third dose of their COVID-19 vaccination to help better boost immune response as concern about variants of the virus grow worldwide.

What You Need To Know

  • Pfizer and BioNTech announced Thursday that they are testing a third dose of their COVID-19 vaccination to help better boost immune response in the wake of rising COVID-19 variants

  • The companies believe their vaccine protects against variants, but these studies will help them be prepared for the future, similar to how doctors suggest getting a flu shot annually

  • Moderna is also testing an experimental third booster against the variant first discovered in South Africa

  • The Food and Drug Administration issued guidance Monday moving away from lengthy clinical trials for vaccines that have been altered to help correct for variants

Pfizer's CEO, Albert Bourla, said in an interview with NBC News that they believe a third dose of the vaccine will boost immune response and help protect against variants such as the ones first discovered in South Africa and the United Kingdom.

"We believe that the third dose will raise the antibody response 10- to 20- fold," Bourla told NBC's Lester Holt.

While Pfizer and BioNTech surmise that their vaccine regimen, which consists of two doses, will protect against those variants, these studies will afford them the ability to be better prepared for the future.

"The rate of mutations in the current virus is higher than expected," Mikael Dolsten, Pfizer's Chief Scientific Officer said. "It’s a reasonable probability that we would end up with regular boosts. And for potent vaccines, it may be that you need to do a strain change every few years, but not necessarily every year."

This is similar to how doctors suggest people get the flu shot annually.

"Every year, you need to go to get your flu vaccine," Bourla said. "It's going to be the same with COVID. In a year, you will have to go and get your annual shot for Covid to be protected."

While evidence suggests the Pfizer-BioNTech vaccine is effective against existing variants, Dolsten said, they "want to be prepared for all options and be data-driven — led by science."

Moderna is also testing an experimental third booster against the variant first discovered in South Africa, they announced Wednesday. 

The Food and Drug Administration issued guidance Monday moving away from lengthy clinical trials for vaccines that have been altered to help correct for variants.