CD4 and COVID-19: This work is strengthened by the use of a large sample of underserved minority adults from Miami, Florida, which experiences a high level of social vulnerability [64], the inclusion of similar proportions of men and women living with and without HIV and COVID-19 vaccination, the representation of Black and Hispanic adults, a population historically underrepresented in vaccine research [23,25,26,49], and the adequate distribution of CD4+ T cell counts ranging from <200 to >500, allowing for proper stratification and regression analyses.