People with moderately to severely compromised immune systems do not always build the same level of immunity as others after their initial COVID-19 vaccine series.
Because of this, the CDC recommends that individuals age 5 and older who received the initial Pfizer-BioNTech or Moderna vaccine series receive a third shot if they:
- Are receiving active cancer treatment for tumors or cancers of the blood
- Have received an organ transplant and are taking medicine to suppress their immune system
- Have undergone a stem cell transplant within the last two years or are taking medicine to suppress their immune system
- Have moderate or severe primary immunodeficiency (such as DiGeorge syndrome or Wiskott-Aldrich syndrome)
- Have advanced or untreated HIV infection
- Are undergoing active treatment with high-dose corticosteroids or other drugs that may suppress immune response
Individuals who received a Johnson & Johnson (J&J) COVID-19 vaccine should receive a booster (preferably Pfizer-BioNTech or Moderna) two months after the initial one-shot J&J vaccination. They should only receive an additional dose of the J&J COVID-19 vaccine if they are unable to receive an mRNA vaccine booster (for example, patients with allergies to a component of the mRNA vaccines).