This review highlights key psychological and behavioral factors that can influence the immune system's response to a vaccine. The results generalize across a wide variety of vaccines, and therefore will likely be relevant to the SARS-COV-2 vaccine. Although the SARS-COV-2 vaccine candidates are highly efficacious, these psychological and behavioral factors can impact how long it takes to develop protective immunity as well as how long the protective immunity lasts. Importantly, even short-term psychological and behavioral interventions can boost the immune system's response to vaccination.