Pfizer CEO says vaccine-resistant COVID-19 variant likely to emerge

"Every time that the variant appears in the world, our scientists are getting their hands around it," Bourla told Fox News. "They are researching to see if this variant can escape the protection of our vaccine. We haven’t identified any yet but we believe that it is likely that one day, one of them will emerge."

According to Bourla, Pfizer has a process in place to develop vaccines for specific variants just 95 days after the variant is identified as a concern.

According to CDC data, 62.5 percent of American adults have been fully vaccinated against COVID-19, with 73.1 percent receiving at least one dose.

While federal officials are looking at the possibility of rolling out a booster shot program amongst Americans in September, the World Health Organization head said on Monday that a two-month moratorium on giving booster shots is necessary to address global vaccine inequalities.

On Monday, the Pfizer-BioNTech vaccine became the first COVID-19 vaccine to receive full FDA approval, a move that is anticipated to boost confidence in the vaccine amongst Americans.

While the Pfizer vaccine has received FDA approval, its ability at preventing infection has dropped, according to a study conducted by the Mayo Clinic.

While the vaccine remains extremely effective at preventing serious illness, its effectiveness at preventing contracting the illness has dropped to 42 percent.