Tuesday, the Food and Drug Administration revoked the emergency use authorizations for Moderna and Pfizer’s original COVID vaccines.

Both vaccines were approved for emergency use more than two years ago after being developed under the Trump administration’s Operation Warp Speed.

The FDA explained in a press release that older vaccines no longer provide complete protection against new virus strains.

The agency stated that it had modified the emergency use authorizations for the initial Moderna and Pfizer-BioNTech vaccines in order to “simplify the vaccination schedule for most individuals.”

“This action includes authorizing the current bivalent vaccines (original and omicron BA.4/BA.5 strains) to be used for all doses administered to individuals 6 months of age and older, including for an additional dose or doses for certain populations,” the FDA said.

Both vaccines, which were approved in December 2020, are no longer authorized for use in the United States, according to the agency.

“The monovalent Moderna and Pfizer-BioNTech COVID-19 vaccines are no longer authorized for use in the United States” the FDA statement said.

According to Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, the majority of Americans have antibodies against the virus due to previous infection or vaccination.

Marks also explained that the extant vaccines and booster recommendations were obsolete.

“At this stage of the pandemic, data support simplifying the use of the authorized mRNA bivalent COVID-19 vaccines, and the agency believes that this approach will help encourage future vaccination,” Marks said.

He added, “Evidence is now available that most of the U.S. population 5 years of age and older has antibodies to SARS-CoV-2, the virus that causes COVID-19, either from vaccination or infection that can serve as a foundation for the protection provided by the bivalent vaccines.”

Marks concluded that COVID remains a “very real risk for many people” and urged Americans to maintain vaccination coverage.

People who are not vaccinated but desire to be should receive a single dose of an updated vaccine instead of the two doses that were previously recommended with the original vaccines, according to the Food and Drug Administration.

Immediately after the emergency authorization of the initial immunizations, many of the nation’s largest cities mandated their use for activities such as shopping and dining.

Former New York City mayor Bill de Blasio terminated the citywide vaccination requirement for city employees in February.

Mayor Eric Adams stated at the time that 96 percent of city employees had “stepped up” by complying with the mandate.

Many who did not comply were terminated or placed on unpaid leave.

According to ABC News, 1,780 New York City employees were dismissed for refusing vaccinations.