The United States Food and Drug Administration will likely approve a second COVID-19 booster shot for adults next week, The New York Times first reported.

As nations relax their COVID-19 protocols amid the spread of the Omicron subvariant known as BA.2, infections are surging across Europe once again. As experts in the U.S. are bracing for a potential surge in the country, sources close to the government said the FDA is expected to approve a fourth dose of Pfizer and Moderna's mRNA vaccines for people above the age of 50, CNN reports.

According to experts, the U.S. could potentially follow the same fate as European countries. University of Warwick virologist Lawrence Young said the nation “certainly needs to take note and consider the impact of yet another more transmissible variant."

A study published earlier this month in the New England Journal of Medicine found that a fourth dose of the COVID-19 vaccine is “somewhat efficacious,” but still “immunogenic” and “safe.”

The authors of the study wrote that there was no significant difference in immune response or “in levels of omicron-specific neutralizing antibodies” between a third and fourth dose of the vaccine.

“Our results suggest that maximal immunogenicity of mRNA vaccines is achieved after three doses and that antibody levels can be restored by a fourth dose,” the authors said. “A fourth vaccination of healthy young health care workers may have only marginal benefits.”