Back to Blog

Are You Immunocompromised? You May Need a 3rd COVID-19 Vaccine

Published on Nov. 10, 2021

If your immune system is compromised, you should plan to receive for a third dose of the Pfizer (ages 12 and up) or Moderna (ages 18 and up) COVID-19 vaccine.

The U.S. Centers for Disease Control and Prevention has recommended a third vaccine dose for those who are moderately to severely immunocompromised. If you qualify, you should receive your third dose at least 28 days after your second dose in the series.

This third dose is critically important to helping at-risk patients build protection against Delta and other highly contagious COVID-19 variants.


Why a third dose?

According to the CDC, a third dose may prevent serious and possibly life-threatening COVID-19 illness in immunocompromised people.

Studies are showing that individuals with weaker immune systems are especially vulnerable to COVID-19. This group may have a hard time building immunity from a two-dose vaccine series, especially as compared with people who aren’t immunocompromised.

Adding a third dose should help boost the antibody response from their initial vaccine series.

The CDC also shares data showing fully vaccinated people who are immunocompromised are making up a large proportion of hospitalized breakthrough cases. This suggests the immunocompromised are more likely to transmit the virus to household contacts.

A third dose may help.


Who qualifies as immunocompromised?

The CDC reports about three percent of the adult population are considered moderately to severely immunocompromised. This term may include individuals who are:

  • Undergoing active cancer treatment for tumors or blood cancers
  • Organ transplant recipients taking medicine to suppress the immune system
  • Stem cell transplant recipients within the last two years or who are taking medicine to suppress the immune system
  • In a state of moderate or severe primary immunodeficiency (such as with DiGeorge syndrome or Wiskott-Aldrich syndrome)
  • HIV-positive (advanced or untreated)
  • Under active treatment with high-dose corticosteroids or other drugs that may suppress immune response

This is not a complete list. If you think your medical history qualifies you as immunocompromised, please ask your family doctor or primary care provider to confirm.


Is a third vaccine dose and a “booster” dose the same thing?

No. A “third dose” is designated for those immunocompromised individuals who completed an initial two-dose mRNA vaccine series (Pfizer or Moderna) and may not have reached a standard immunity level. In this case a third dose may be recommended.

The FDA has recently authorized “booster” doses of all three available COVID-19 vaccines for eligible non-immunocompromised individuals. A booster dose is recommended when the standard immunity gained from the patient’s original single dose or 2-dose series is reduced over time.


What if I received the single-dose Johnson & Johnson vaccine?

CDC guidance recommends that moderately to severely immunocompromised people who received Johnson & Johnson’s Janssen COVID-19 vaccine should not receive an additional primary dose. These individuals should get a booster shot of their choosing at least 2 months after their single-dose primary shot. The CDC states that a single dose of the Johnson & Johnson COVID-19 vaccine has lower vaccine effectiveness compared to two doses.


Can I request a different vaccine for my third dose?

You should plan to receive a third dose of the same COVID-19 mRNA vaccine as your original two-dose series (either Pfizer or Moderna). If your original vaccine is unavailable or unknown, you can receive either mRNA COVID-19 vaccine.

Note: if possible, please bring your vaccination card with you to your third-dose appointment.


If I qualify, where can I get my third dose?

Munson Healthcare primary care practices are now scheduling third dose COVID-19 vaccine appointments for immunocompromised individuals. You must have already completed a two-dose series of either the Pfizer or Moderna vaccines.

If you qualify for a third dose based on the above criteria, please reach out to your primary care provider to request an appointment. If you’re unsure, or without a family doctor, please call Munson Healthcare Ask-A-Nurse at 231-935-0951.

Ask-A-Nurse   231-935-0951

Other locations administering third-dose vaccines may include nearby pharmacies and your local health department. Find vaccine providers near you at vaccinefinder.org.