Pfizer is examining the possibility of adding a third dose to its coronavirus vaccine protocol, NBC News reported.
On Thursday, the company announced that a booster dose is being studied among those who received their first two doses over six months ago.
In an interview with NBC News, Pfizer CEO Albert Bourla said he hopes that a third dose will offer even better protection against coronavirus variants.
"We believe that the third dose will raise the antibody response 10- to 20- fold," he said.
Two doses of the Pfizer-BioNTech coronavirus vaccine were shown last year to have 95% efficacy, and more recently, a study by Israel's largest health fund, Clalit, showed that two doses of the Pfizer-BioNTech vaccine have 94% efficacy.
Studies on the third dose will monitor both its safety and its efficacy, in subjects ages 18 to 55 and in subjects ages 65-85, who were part of the company's initial Phase 1 and 2 trials.
The third dose will be the same as the first two doses, the company said.
In addition, Pfizer plans to begin testing whether a modified version of the vaccine would neutralize the South African coronavirus mutation.
Bourla added that his company's goal is to tweak the vaccine within 100 days, if such a move becomes necessary..