The CDC has recently updated its guidance, and now recommends a 3rd dose of mRNA vaccine for immunocompromised individuals.
The third dose of the vaccine is not a booster dose, but instead is an additional dose for persons in whom the immune response may have been suppressed following the first two doses. Immunocompromised individuals include people with certain medical conditions or people receiving treatments that are associated with moderate to severe immune compromise, including:
Active or recent treatment for solid tumor and hematologic malignancies
Receipt of solid-organ transplant and taking immunosuppressive therapy
Receipt of CAR-T-cell or hematopoietic stem cell transplant (within 2 years of transplantation or taking immunosuppression therapy)
Moderate or severe primary immunodeficiency (e.g., DiGeorge Syndrome, Wiskott-Aldrich Syndrome)
Advanced or untreated HIV infection; or/and
Active treatment with high-dose corticosteroids (i.e., ≥ 20 mg prednisone or equivalent per day), alkylating agents, antimetabolites, transplant-related immunosuppressive drugs, cancer chemotherapeautic agents classified as severely immunosuppressive, tumor-necrosis (TNF) blockers, and other biologic agents that are immunosuppressive or immunomodulatory.