Despite prioritization of immunocompromised individuals within COVID-19 vaccine protocols, this population remains vulnerable to adverse effects of SARS-CoV-2 infection, including high morbidity and mortality.

Patients with various immunocompromising conditions exhibit diverse responses to SARS-CoV-2 infection, and available vaccines elicit lower immune responses, particularly in solid organ transplant recipients.

Additional COVID-19 vaccine doses may enhance vaccine effectiveness and protect against emerging SARS-CoV-2 variants.

Continued investigation of COVID-19 vaccine dosing and intervals, heterologous vaccination regimens, and breadth of coverage of emerging variants is needed to optimize vaccination recommendations to protect this vulnerable population.