The Food and Drug Administration (FDA) in the United States has made modifications to the emergency use authorizations (EUAs) of the bivalent mRNA Covid-19 vaccines manufactured by Pfizer-BioNTech and Moderna.

The most recent change is intended to make the vaccine schedule easier to follow for the vast majority of individuals.

As a result of the adjustments, the existing bivalent vaccinations that protect against the original and Omicron BA.4/BA.5 strains of the virus may now be used for all doses that are given to patients aged six months and older.

This also includes the administration of an extra dosage or doses to specific individuals.

According to the Food and Drug Administration (FDA), Pfizer-BioNTech and Moderna’s monovalent Covid-19 vaccines are no longer permitted for use in the United States.

According to the revised EUAs, it is now permissible to provide just a single dose of a bivalent vaccination to the majority of patients who have previously been immunized with a monovalent Covid-19 vaccine but have not yet received a dose of a bivalent vaccine.

People aged 65 and older who have previously been given a single dose of a bivalent vaccination and who want to get a subsequent dose must wait at least four months after their first bivalent dose to do so.

Those individuals who have specific types of immunocompromise and who have previously received a bivalent vaccination are eligible to receive a second dose of the bivalent Covid-19 vaccine at least two months after the first dose of the bivalent vaccine.

Immunocompromised persons up to the age of four years old will have eligibility requirements to take extra doses. These eligibility criteria will depend on the vaccination that has already been administered.

On the other hand, the regulatory body has implemented certain interim limits for those who have previously been given a single dose of a bivalent vaccination.

A single bivalent vaccination dosage may also be administered to most unvaccinated persons, rather than many initial monovalent mRNA vaccine doses.

Children aged six months to five years who have not yet had their bivalent vaccines have the option of receiving either a two-dose series of the Moderna bivalent vaccine or a three-dose series of the Pfizer-BioNTech bivalent vaccine.

Those aged five and older have the option of receiving either a single dose of the Pfizer-BioNTech bivalent vaccination or two doses of the Moderna bivalent vaccine.

Children who have previously had one, two, or three doses of a monovalent Covid-19 vaccination and are between the ages of six months and five years old are eligible to receive a bivalent vaccine.

Peter Marks, director of the FDA Center for Biologics Evaluation and Research, remarked that “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.

“Evidence is now available that most of the US population five years of age and older have 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.”