COVID-19 Third Doses (Boosters)

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The Centers for Disease Control and Prevention and U.S. Food and Drug Administration have authorized a third dose (booster) of the Pfizer-BioNTech COVID-19 vaccine (Comirnaty), Moderna and the Johnson & Johnson COVID-19 vaccine for most populations.

People age 18 and older who originally received the Moderna vaccine should get a third dose approximately five months or more after they received their second dose of vaccine. People age 5 and older who originally received the Pfizer vaccine should get a third dose approximately five months or more after they received their second dose of vaccine. If possible, children should receive a third dose prior to summer camp, vacation plans, and other activities. People age 18 and older who originally received the Johnson & Johnson vaccine should get a second dose approximately two months or more after their single dose. 

CDC also authorized a “mix and match” approach to third doses for people age 18 and older. Adults may get a different type of vaccine for their third dose than their original series.

If you received a Johnson & Johnson vaccine for your first dose, you should get a dose of either Pfizer or Moderna two months or more after you first got vaccinated.

Adults age 50 and older are eligible for a second booster dose at least four months after their first booster. While an mRNA vaccine (Moderna or Pfizer) is preferred in most situations for the first booster, the second booster must be an mRNA vaccine.


Who is eligible to receive a third dose (booster)?

You should get a third dose (booster) if you:

  • Are 5 or older and received your second dose of Pfizer at least five months ago.
  • Are 18 or older and received your second dose of Moderna at least five months ago.
  • Are 18 or older and received the Johnson & Johnson vaccine for your initial dose at least two months ago.

Because COVID-19 is spreading quickly throughout the state, Colorado is a high-risk place to live and work. Anyone who is 5 or older who would like a third dose and is due for one should make a plan to get one. We encourage you to speak with your health care provider if you have questions about third doses.

Where can I get my third dose (booster)?

Third doses (boosters) are available at local vaccine provider sites. Click here to find one in your area. El Paso County Public Health Immunization Clinic is offering boosters; call 719-578-3199, option 5 to schedule. It's a good idea to bring your Vaccine Card to your appointment, but no other identification or insurance is required. Third doses, like all COVID-19 vaccines, are free.

Is the third dose safe? Is it needed?

The CDC and FDA have authorized a third vaccine dose for the Pfizer vaccine and Moderna vaccine, and a second dose of the Johnson & Johnson vaccine, for most populations, after analyzing safety and immune response in a subset of clinical trial participants as well as real-world data. To learn more about how the authorization process worked click here and here.

The available data suggest waning immunity in some populations who are fully vaccinated. The availability of these authorized third doses is important for continued protection against COVID-19 disease.

On May 19, 2022, Centers for Disease Control and Prevention (CDC) approved a third (booster) dose of the Pfizer COVID-19 vaccine for children aged 5 through 11 years. This announcement came after CDC’s Advisory Committee on Immunization Practices voted to recommend a third dose of the Pfizer vaccine in this younger population. FDA authorized the use of a single booster dose for children 5 through 11 years on May 17, 2022.

Why is a third dose being recommended now?

As the science and the virus evolves, official policies and recommendations can and do change. Boosters are common for many vaccines. The scientists and medical experts who developed the COVID-19 vaccines continue to closely watch for signs of waning immunity, how well the vaccines protect against new mutations of the virus, and how that data differs across age groups and risk factors.

Who is eligible for a fourth dose (second booster)?

Adults age 50 years and older are eligible for a fourth vaccine dose (second booster) at least four months after their first booster. A second booster must be an mRNA vaccine (Moderna or Pfizer).


About Shots for Immunocompromised People

After completing the primary series, the Centers for Disease Control and prevention recommends that some moderately or severely immunocompromised people, should get an additional primary shot of the Pfizer COVID-19 Vaccine or the Moderna COVID-19 vaccine. People age 12 and up who qualify may receive this additional primary dose of the Pfizer vaccine, while people age 18 and up who qualify may receive the additional Moderna dose. This recommendation pertains to immunocompromised persons who received the mRNA two-dose vaccine series. 

Everyone 5 years and older, including immunocompromised people, should get an additional dose, following the primary series (booster). If you are eligible for an additional primary shot, you should get this dose first before you get a fourth dose (booster).

Answers to common questions are listed below.

Am I considered moderately or severely immunocompromised?

People are considered to be moderately or severely immunocompromised if they have:

  • Been receiving active cancer treatment for tumors or cancers of the blood
  • Received an organ transplant and are taking medicine to suppress the immune system
  • Received a stem cell transplant within the last 2 years or are taking medicine to suppress the immune system
  • Moderate or severe primary immunodeficiency (such as DiGeorge syndrome, Wiskott-Aldrich syndrome)
  • Advanced or untreated HIV infection
  • Active treatment with high-dose corticosteroids or other drugs that may suppress your immune response

People should talk to their healthcare provider about their medical condition, and whether getting an additional primary shot is appropriate for them.

Why do immunocompromised people need an additional primary shot?

An additional primary shot may prevent serious and possibly life-threatening COVID-19 in people who may not have responded to their two-dose mRNA COVID-19 vaccine primary series. The mRNA COVID-19 vaccines (Pfizer-BioNTech or Moderna) have been shown to prevent COVID-19 following the two-dose series. Limited information suggests that immunocompromised people who have low or no protection after two shots of mRNA vaccines may have an improved immune (antibody) response after an additional primary dose of the same vaccine.

Can I mix and match vaccine brands for my additional primary shot?

No, the vaccine used for the additional primary shot should be same as the vaccine used for the primary vaccine series. If the mRNA vaccine product given for the first two doses is not available or is unknown, either mRNA COVID-19 vaccine product may be administered.

When can I receive my third dose?

  • People age 5+ who are moderately or severely immunocompromised should get an additional primary shot of Pfizer-BioNTech COVID-19 vaccine, given 28 days after second shot.
  • People age 18+ who are moderately or severely immunocompromised should get an additional primary shot of Moderna COVID-19 vaccine, given 28 days after second shot.
  • No additional primary shot is recommended at this time for people who received the Johnson & Johnson vaccine.

What is the difference between an additional primary shot and a booster shot?

An additional primary dose is administered to people with moderately or severely compromised immune systems. The additional primary dose of an mRNA COVID-19 vaccine is intended to improve immunocompromised people’s response to their vaccine primary series. An additional dose (booster) is administered when a person has completed their vaccine primary series to enhance or restore protection against COVID-19 which may have decreased over time.

Will I need to pay or have insurance?

Additional doses are free. No ID, insurance, or proof of medical history is required to receive an additional dose. Coloradans may self-report their immunocompromising conditions to vaccine providers.