CDC panel recommends third dose of COVID-19 vaccine for immunocompromised people

key takeaways

  • CDC advisory panel votes to recommend additional vaccinations for immunocompromised people.
  • This recommendation applies to people who are moderately to severely immunosuppressed.
  • Studies show that the third dose of Moderna and Pfizer/BioNTech’s mRNA vaccine is safe and effective. Johnson & Johnson’s vaccine is not authorized for use as a third dose in immunocompromised people, although it is authorized as a booster.

U.S. health officials voted on August 13, 2021 to recommend an additional dose of the COVID-19 vaccine for some immunocompromised people.

Eight advisory panels from the Centers for Disease Control and Prevention (CDC) voted unanimously to support the recommendation.

Shortly after, CDC Director Rochelle Walensky signed off on the recommendation, allowing millions of people with moderate and severe immunocompromised access to receive a third dose of either a Pfizer or Moderna vaccine. For individuals with a weak or non-existent immune response after the initial dose, additional shots may give them a higher degree of protection against COVID-19.

“I want to be able to visit with vaccine friends and family without fear of being a breakthrough case,” one cancer survivor said in public comments.

The vote comes on the heels of the U.S. Food and Drug Administration (FDA) authorizing a third dose of the COVID-19 vaccine for organ transplant recipients and individuals with similar levels of immunosuppression.

Who is eligible for the third dose?

The CDC recommendation is for people with moderate or severe immunocompromise.

This may include people with the following medical conditions or treatment:

  • Active or recent treatment of solid tumors and hematological malignancies.
  • Received solid organ or recent hematopoietic stem cell transplantation and received immunosuppressive therapy.
  • Receive CAR-T cell or hematopoietic stem cell transplantation (within two years after transplantation or receive immunosuppressive therapy).
  • Moderate or severe primary immunodeficiency (eg, DiGeorge, Wiskott-Aldrich syndrome).
  • Advanced or untreated HIV infection.
  • Use of high-dose corticosteroids (eg, greater than or equal to 20 mg per day of prednisone or equivalent), alkylating agents, antimetabolites, transplant-related immunosuppressive drugs, cancer chemotherapy drugs classified as severely immunosuppressed, TNF blockers Active treatment with other drugs Biologics with immunosuppressive or immunomodulatory effects.

what does this mean to you

If you are moderately or severely immunocompromised, talk to your doctor to determine if and when you should receive a third dose of the mRNA vaccine.

The CDC estimates that 2.7 percent of U.S. adults, or about 7 million people, are immunocompromised. These people may receive a third injection 28 days or more after completing the two-dose mRNA series.

This recommendation applies to people 5 years of age and older who received the Pfizer vaccine series and those 18 years and older who received the Moderna vaccine series and who are moderately or severely immunocompromised. People should try to get additional doses that match their earlier doses. If not available, a mixed mRNA vaccine could be ok for people 18 and older, the panel said. Children and adolescents ages 5-17 are currently only vaccinated against Pfizer.

So far, the panel doesn’t have enough data to recommend that recipients of the J&J vaccine receive an additional or third dose of the vaccine (they could be boosted). The FDA said it is working to ensure that immunocompromised people who receive the Johnson & Johnson vaccine are optimally protected.

Strengthening protection for the most vulnerable

Immunocompromised individuals are more likely to become seriously ill from COVID-19 because they are less likely to develop protective antibodies after vaccination. For example, immune responses to vaccines in organ transplant patients can range from 0% to 79%, and about 40% of people hospitalized with breakthrough infections are immunocompromised, the panel said.

Among those who had no detectable antibody response to the initial program, one-third to half had some immunity after the third dose. But health experts aren’t entirely sure how the rise in antibodies will translate to COVID-19 prevention in this group.

The third dose appeared to be “only moderately effective,” Peter Marks, MD, director of the FDA’s Center for Biologics Evaluation and Research, said at the meeting. He added that because individuals respond differently to additional doses, recipients should continue to wear masks, maintain social distancing and take other safety precautions.

The CDC does not recommend antibody testing before or after additional injections. Currently, there are no FDA-approved antibody tests to accurately measure immunity following a vaccine.

Clinicians caring for moderately and severely immunosuppressed patients should consider patients when recommending a third dose unique needs.

“This is a highly heterogeneous group with very complex medical needs that will vary by condition,” Doolin said. “Our attempt here is to use these clinical considerations as a starting point, which will certainly need to be adjusted by the clinical care team treating these individuals.”

As with earlier injections, the third dose will be free and administered in pharmacies and other health care settings.

To minimize barriers, the panel said the third injection would not require patients to show a letter from their doctor.

Booster for the general population

As COVID-19 cases, hospitalizations and deaths continue to rise in the U.S. due to the spread of the highly contagious Delta variant, other populations are now eligible for booster doses.

FDA now authorizes booster dose for all individuals age 12 and older in the U.S.

According to the CDC, you are eligible for a COVID-19 booster shot if:

  • You are at least 12 years old and have received Pfizer’s primary vaccine series at least five months ago
  • You are 18 years old and have received Moderna’s primary vaccine series at least five months ago
  • You are over 18 years old and received the Johnson & Johnson vaccine at least two months ago

Eligible adults can choose any authorized COVID-19 booster—regardless of the type of vaccine used for initial vaccination (although mRNA COVID-19 vaccine is preferred in most cases). Children and adolescents ages 12 to 17 who have completed the Pfizer Junior Series are only eligible for Pfizer Boosters.


Pfizer and Johnson & Johnson’s boosters will use the same dose as the initial vaccine, while Moderna’s dose will be half that (50 micrograms).

The World Health Organization has called on wealthier countries to avoid booster shots until countries with lower vaccination rates have access to existing vaccines. France, Israel, the United Kingdom and Germany have already announced additional doses for immunocompromised people.

The information in this article is current as of the date listed, which means that you may have updated information as you read this article. For the latest updates on COVID-19, visit our Coronavirus news page.