You are able to schedule a Third Dose of COVID-19 Vaccine if you are an immunocompromised individual. The CDC guidelines for this are as follows:
The additional vaccine should be considered for people with moderate to severe immune compromise due to a medical condition, or receipt of immunosuppressive medications or treatments.
This includes people who have:
Active treatment for solid tumor and hematologic malignancies
Receipt of a 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 (such as DiGeorge syndrome, Wiskott-Aldrich
syndrome)
Advanced or untreated HIV infection
Active treatment with high-dose corticosteroids (≥20mg prednisone or equivalent per day), alkylating agents, antimetabolites, transplant-related immunosuppressive drugs, cancer chemotherapeutic agents classified as severely immunosuppressive, tumor-necrosis (TNF) blockers, and other biologic agents that are immunosuppressive or immunomodulatory.