As the COVID-19 pandemic continues, ongoing studies help inform healthcare professionals about the different immune responses and reactions among various groups within the population. Data has shown that people who are moderately to severely immunocompromised are especially vulnerable to the virus due to the inability to build the same level of immunity after vaccination as non-immunocompromised people. Small studies have also found that immunocompromised people made up a large portion of breakthrough cases requiring hospitalization, suggesting they could be more likely to transmit COVID-19 to other members of their household. Given this information, the CDC recommends that moderately to severely immunocompromised people receive an additional dose of mRNA COVID-19 vaccine at least 28 days after a second dose of Pfizer-BioNTech COVID-19 vaccine or Moderna COVID-19 Vaccine. People who should receive this additional dose include:

  • Anyone who has received an organ transplant and taking immunosuppressants
  • Those with advanced or untreated HIV infection
  • Recipients of a stem cell transplant within the last 2 years or taking immunosuppressants
  • Those receiving active cancer treatment for tumors or blood cancers
  • Anyone who has a moderate to severe primary immunodeficiency
  • Those undergoing active treatment with high-dose corticosteroids or other drugs that may suppress immune response

For questions and additional information, please visit the CDC’s website: