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FDA OKs new monovalent COVID-19 vaccines

September 11, 2023

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The Food and Drug Administration (FDA) has authorized newly formulated COVID-19 vaccines from two manufacturers.

The monovalent vaccines from Moderna and Pfizer-BioNTech were authorized for everyone 6 months and older. The Centers for Disease Control and Prevention’s (CDC’s) Advisory Committee on Immunization Practices meets Tuesday to make clinical recommendations on use of the vaccines. Vaccination could begin shortly after approval from the CDC director.

“Vaccination remains critical to public health and continued protection against serious consequences of COVID-19, including hospitalization and death,” Peter Marks, M.D., Ph.D., director of the FDA’s Center for Biologics Evaluation and Research, said in a press release. “The public can be assured that these updated vaccines have met the agency’s rigorous scientific standards for safety, effectiveness, and manufacturing quality. We very much encourage those who are eligible to consider getting vaccinated.”

The FDA made the following authorizations:

  • Individuals 5 years of age and older regardless of previous vaccination are eligible to receive a single dose of an updated mRNA COVID-19 vaccine at least two months after the last dose of any COVID-19 vaccine.
  • Individuals 6 months through 4 years of age who previously were vaccinated against COVID-19 are eligible to receive one or two doses of an updated mRNA COVID-19 vaccine. Timing and number of doses to administer depend on the previous COVID-19 vaccine received (see resources).
  • Unvaccinated individuals 6 months through 4 years of age are eligible to receive three doses of the updated authorized Pfizer-BioNTech COVID-19 vaccine or two doses of the updated authorized Moderna COVID-19 vaccine.

The FDA said it expects side effects to be similar to previous versions of the vaccines.

The authorizations come as the CDC reports just over 17,000 COVID hospitalizations in the past week, an increase of 15.7%. Deaths rose 10.5% in the most recent week.

Following recommendations from its expert advisers, the FDA requested the new monovalent formulation with an XBB.1.5 strain in June, aiming to better match circulating virus variants. The original strain and other early variants no longer are circulating. Experts also noted most people have antibodies against the original strain from vaccination, infection or both.

Vaccine manufacturers presented data from animal studies showing updated XBB vaccine formulations elicit stronger neutralizing antibody responses against these strains than current vaccines. A Moderna study with 101 adults also showed improved neutralizing antibody response against XBB and a similar safety profile to previous COVID vaccines. Recent studies show the new vaccines also should be able to neutralize EG.5, which is the most commonly circulating variant, as well as the BA.2.86 strains, according to the FDA.

The new vaccines will be the first COVID vaccines sold on the commercial market. Monday’s actions mean the bivalent Moderna and Pfizer-BioNTech vaccines no longer are authorized for use.


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