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Press Release

(Santa Ana, CA) - Following the US Food and Drug Administration (FDA) regulatory action last week to amend the Emergency Use Authorization (EUA) on COVID-19 vaccinations, the Centers for Disease Control and Prevention (CDC) transitioned recommendations to using only the mRNA bivalent vaccines (both Moderna and Pfizer) and the use of the Monovalent (original) mRNA COVID-19 vaccines is no longer authorized.   
According to the CDC’s Advisory Committee on Immunization Practices (ACIP), the simplification is supported by available data and field experience as evidence shows that most people in the US above 5 years of age, have antibodies to SARS-CoV-2 from prior vaccination but because of waning of this protection over time, the bivalent vaccines are critical to boost protection.
"This is a welcomed development, making COVID-19 vaccination administration easier for both health care providers and clients," said Dr. Regina Chinsio-Kwong, OC Health Care Agency’s (HCA) Chief of Public Health Services and County Health Officer. "Individuals who never had any COVID-19 vaccines as well as those who had previous vaccines can now be vaccinated with the same bivalent boosters, making access and administration less complicated."

In addition to eliminating the monovalent 2-dose vaccine, the revised EUA includes several updates, specifically:

  • Individuals 65 years of age and older who have received a single dose of a bivalent vaccine should receive one additional dose at least four months following their initial bivalent dose. 
  • Most individuals with certain kinds of immunocompromise who have received a bivalent COVID-19 vaccine should receive a single additional dose of a bivalent COVID-19 vaccine at least 2 months following a dose of a bivalent COVID-19 vaccine, and additional doses may be administered at the discretion of, and at intervals determined by, their health care provider. However, for immunocompromised individuals 6 months through 4 years of age, eligibility for additional doses will depend on the vaccine previously received. 
  • Most unvaccinated individuals should receive a single dose of a bivalent vaccine, rather than multiple doses of the original monovalent mRNA vaccines. 
  • Children 6 months through 5 years of age who are unvaccinated should receive either a two-dose series of the Moderna bivalent vaccine (6 months through 5 years of age) OR a three-dose series of the Pfizer-BioNTech bivalent vaccine (6 months through 4 years of age). Children who are 5 years of age may receive two doses of the Moderna bivalent vaccine or a single dose of the Pfizer-BioNTech bivalent vaccine. 
  • Children 6 months through 5 years of age who have received one, two or three doses of a monovalent COVID-19 vaccine should receive a bivalent vaccine, but the number of doses that they receive will depend on the vaccine and their vaccination history. Read more about the importance of infant immunization here.

The CDC's recommendations for use of (monovalent) Novavax COVID-19 and Johnson & Johnson ‘s Jansen COVID-19 vaccines were not affected by the change in recommendations.
As COVID-19 continues to be a risk for many people, the HCA strongly encourages individuals to stay current with vaccination as available data continues to demonstrate that vaccines prevent the most serious outcomes of COVID-19 such as severe illness, hospitalization and death. As the protection from COVID-19 vaccination wanes over time, people who are over 65 years of age or immunocompromised, may consider getting a booster vaccine if they received their last dose more than four months or two months ago, respectively.
For individuals who cannot or will not receive an mRNA vaccine, alternatives to mRNA COVID-19 vaccines remain available as the CDC's recommendations for use of (monovalent) Novavax COVID-19 vaccines were not affected by the change in recommendations.
The HCA will continue to update guidance in cooperation with state and federal partners. In order to ensure Orange County residents have the information needed, the HCA responds to community inquiries through the Agency’s Health Referral Line at 1-800-564-8448, Monday through Friday from 8 a.m. to 5 p.m.
For more information on COVID-19 including resources, case counts, vaccination, and testing in Orange County, visit