With the recent approval for COVID-19 boosters by the Federal Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC), I wanted to touch on one specific high-risk population in which the recommendation differs slightly – individuals with compromised immune systems. To start, it’s important to note that the current FDA-authorized COVID-19 vaccines do not include live virus and can be safely given to immunocompromised people. However, research has shown that some individuals with suppressed immune systems do not develop the same level of immunity after vaccination and may benefit from an additional dose (CDC, 2021a). Without the production of adequate antibodies, these individuals are at a higher risk of becoming critically ill from COVID-19.
 
Individuals with moderate to severely compromised immune systems make up close to 3% of the adult U.S. population. A study found that 44% of hospitalized breakthrough cases in the U.S. were among this high-risk group (Oliver ,2021). The Advisory Committee on Immunization Practices (ACIP) encourages these individuals to receive an “additional” or third dose of mRNA vaccine within a tighter timeframe, at least 28 days after the completion of the primary 2-dose series (CDC, 2021b). This additional dose was found to enhance the antibody response and increase the proportion of vaccine responders. The ACIP advises that the same mRNA vaccine be used for all 3 doses if possible. If the same mRNA vaccine is not available, the other mRNA COVID-19 vaccine may be administered.
 
The CDC (2021b) currently recommends an additional dose of mRNA vaccine for the following individuals who:

• Are undergoing cancer treatment for tumors or cancers of the blood
• Received a solid-organ transplant and are taking immunosuppressive medications
• Received CAR-T-cell or stem cell transplant (within 2 years of transplantation or are taking immunosuppressive medications)
• Have moderate or severe primary immunodeficiency (i.e., DiGeorge syndrome, Wiskott-Aldrich syndrome)
• Have advanced or untreated HIV infection
• Are receiving active treatment with high-dose corticosteroids or other drugs that may suppress the immune response such as:
  • High-dose corticosteroids (i.e., 20 mg prednisone or greater per day for 14 days or longer)
  • Alkylating agents
  • Antimetabolites
  • Transplant-related immunosuppressive drugs
  • Chemotherapeutic agents classified as severely immunosuppressive
  • Tumor necrosis factor (TNF) blockers
  • Other biologic agents that are immunosuppressive or immunomodulatory

Booster Dose for the Immunocompromised?

There have been questions as to whether immunocompromised individuals should still receive a booster dose following the completion of the two-dose mRNA vaccine series and third additional dose. The FDA recently authorized booster shots for this high-risk group and the CDC revised its guidelines to indicate this change. The new guidelines state that moderately to severely immunocompromised individuals 18 years or older who completed an mRNA COVID-19 primary vaccine series and received an additional third mRNA vaccine may receive a single COVID-19 booster dose (Pfizer-BioNTech, Moderna [half dose], or Janssen) at least 6 months after completing the third mRNA vaccine dose for a total of four doses (CDC, 2021c). Individuals who initially received a single Janssen/J&J COVID-19 vaccine should receive a single COVID-19 booster vaccine (Pfizer-BioNTech, Moderna [half dose], or Janssen) at least 2 month (8 weeks) after receiving their initial Janssen primary dose. No more than two Janssen doses should be given. The patient’s provider and clinical team should determine the appropriate timing and spacing of vaccination with regard to other treatments.

General Considerations

Advise your immunocompromised patients to continue personal measures to reduce exposure to COVID-19 infection such as masking, physical distancing, and avoiding crowds, even after they are fully vaccinated. Encourage household members and other close contacts of immunocompromised patients to get vaccinated as well.
 

Reference
Centers for Disease Control and Prevention (2021a, October 18). COVID-19 Vaccines for moderately to severely immunocompromised people. Retrieved from https://www.cdc.gov/coronavirus/2019-ncov/vaccines/recommendations/immuno.html
 
Centers for Disease Control and Prevention (2021b, October 25). Considerations for COVID-19 vaccination in moderately and severely immunocompromised people. Retrieved from https://www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html#considerations-covid19-vax-immunocopromised
 
Centers for Disease Control and Prevention (2021c, October 25). Considerations for use of a COVID-19 vaccine booster dose. Retrieved from https://www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html#considerations-covid19-vax-booster
 
Oliver, S. (2021). Data and clinical considerations for additional doses in immunocompromised people. Centers for Disease Control and Prevention ACIP Meeting July 22 ,2021. Retrieved from https://www.cdc.gov/vaccines/acip/meetings/downloads/slides-2021-07/07-COVID-Oliver-508.pdf