COVID-19 Vaccines

Page last updated/reviewed 9/22/2023

Latest Updates

The updated COVID-19 vaccine is available throughout San Diego County. 

Recommendations

Syringe

About Vaccines

About Vaccines

Getting Your Vaccine

Getting Your Vaccine

Information for Vaccine Providers

Health professionals

Recommendations

COVID-19 vaccines are safe and effective. The County of San Diego is following federal and state guidelines and working with community partners to provide vaccinations to the public.

Everyone Aged 5 Years and Older

  • 1 dose of the updated (2023-2024) COVID-19 vaccine, regardless of prior vaccine history, as long as it has been at least 2 months since the last dose of any COVID-19 vaccine.

Younger Children and Infants (Aged 6 Months to 4 Years)

  • 1 or 2 doses of the updated (2023-2024) COVID-19 vaccine, if they have been previously vaccinated against COVID-19. The timing and number of doses depends on the previous COVID-19 vaccine received.
  • See below, or visit the Centers for Disease Control and Prevention (CDC) for the full schedule.
    • Pfizer-BioNTech
      • 1 previous dose: 2nd dose 3-8 weeks after 1st dose, 3rd dose at least 8 weeks after 2nd dose.  
      • 2 or more previous doses: 1 dose at least 8 weeks after the last dose.
    • Moderna
      • 1 previous dose: 4-8 weeks after the last dose.
      • 2 or more previous doses: 1 dose at least 8 weeks after the last dose.

Younger Children and Infants (Aged 6 Months to 4 Years) Who Are Not Vaccinated

  • 2 or 3 doses of the updated (2023-2024) COVID-19 vaccine, depending on which vaccine they receive.
  • See below, or visit the Centers for Disease Control and Prevention (CDC) for the full schedule. 
    • Pfizer-BioNTech:
      • 1st dose, followed by 2nd dose 3-8 weeks after the 1st dose, then 3rd dose at least 8 weeks after the 2nd dose.
    • Moderna:
      • 1st dose, followed by 2nd dose 4-8 weeks after the first 1st dose.

People Who May Get Additional Updated COVID-19 Vaccines

  • The CDC recommends adults ages 65 years and older to speak with their healthcare provider about receiving a second dose. People with immunocompromised systems are recommended to receive a 2nd dose, and potentially additional doses, of the updated COVID-19 vaccine for increased immune protection, with the approval of their healthcare provider.

People Who May Want Another COVID-19 Vaccine Option

  • People 12 years and older who are unable or choose not to get an updated Pfizer-BioNTech or Moderna COVID-19 vaccine can consider other options to get up-to-date.
  • Visit the Centers for Disease Control and Prevention for details.

If You Had or Currently Have COVID-19

  • You still need to stay up-to-date with your vaccines. But you may consider delaying your next vaccine dose by 3 months from:
    • When your symptoms started, or
    • If you had no symptoms, when you first received a positive test.

Stay Up-to-Date

When are you up-to-date with COVID-19 vaccinations?

Everyone aged 5 years and older

  • You are up to date when you get 1 updated COVID-19 vaccine.

Children aged 6 months—4 years

  • You are up to date when you get all recommended doses, including at least 1 dose of updated COVID-19 vaccine.

Children aged 6 months—5 years who got the Moderna COVID-19 vaccine

  • You are up to date when you get 2 Moderna COVID-19 vaccine doses, including at least 1 updated COVID-19 vaccine dose.

People who got the Novavax COVID-19 vaccine

  • You are up to date when you get the Novavax COVID-19 vaccine doses approved for your age group or when you get 1 updated COVID-19 vaccine.

People who got the Johnson & Johnson/Janssen COVID-19 vaccine

  • You are up to date when you get 1 updated COVID-19 vaccine.

About

Vaccines authorized by the U.S. Food and Drug Administration (FDA) currently include:

These vaccines are given as a shot in the muscle of the upper arm or in the thigh of a young child. COVID-19 vaccine ingredients are considered safe for most people.

How do the COVID-19 vaccines work? 

  • The vaccines teach your body to recognize COVID-19, so it is prepared to fight the virus.
  • Messenger RNA vaccines (mRNA), like Pfizer-BioNTech and Moderna, provide instructions for your body to build a small protein that looks like a piece of COVID-19. This protein helps your body recognize the virus if you become infected. 
  • Protein subunit vaccines, such as Novavax, include harmless proteins of the virus that cause COVID-19. This helps your body recognize the virus if you become infected.
  • Bivalent vaccines ("updated vaccine") protects against both the original virus that causes COVID-19 and the Omicron variant BA.4 and BA.5.

How well do COVID-19 vaccines work?

  • People who are up-to-date have lower risk of severe illness, hospitalization, and death from COVID-19 than people who are unvaccinated or who have only received the primary series.
  • Updated COVID-19 boosters can help build up protection that has decreased since previous vaccination. The updated boosters provide added protection against the recent Omicron subvariants that are more contagious than the previous ones. The recent subvariants, BA.4 and BA.5, are very closely related to the original variant, Omicron, with very small differences between itself and the original variant.

Are COVID-19 vaccines safe?

  • COVID-19 vaccines have undergone – and will continue to undergo – the most intensive safety monitoring in U.S. history. 
  • Evidence from the hundreds of millions of COVID-19 vaccines already administered in the U.S., and the billions of vaccines administered globally, demonstrates that they are safe and effective.

Are there side effects to the COVID-19 vaccine?

  • There may be some mild side effects that go away in a day or two. Side effects are a sign that the vaccine is working. Side effects could include:
    • Pain, redness, or swelling in the arm where you received the vaccine. You can apply a cool, wet washcloth to reduce pain.
    • Mild flu-like symptoms, like tiredness, nausea, muscle aches, chills, headache, or fever. Drink plenty of fluids and rest to feel more comfortable.
  • Severe allergic reactions to vaccines are rare but can happen. 

What are booster doses?

  • A booster dose refers to a vaccine given after the primary series to boost protection which might have waned over time.

What is the difference between monovalent and bivalent boosters?

  • Previous boosters are called “monovalent” because they were designed to protect against the original (i.e., one) virus that causes COVID-19. 
  • Updated boosters are called “bivalent” because they protect against both (i.e., two viruses) the original virus and the Omicron variants that causes COVID-19. More recent variants of Omicron are also covered by the vaccine.

Resources

County of San Diego

California Department of Public Health (CDPH)

Centers for Disease Control and Prevention (CDC)

Food and Drug Administration (FDA)