Researchers of a study sought to examine seroconversion rates and antibody titers after two-dose COVID-19 vaccination in those with HIV with impaired CD4+ T-cell counts. Researchers collected postvaccination serology results from a university hospital for this population who were given the vaccine series between March 2021 and September 2021, and who were also tested for anti spike antibodies 8 to 150 days after being administered the second dose. A total of 105 patients with HIV were included in the study, with 54 patients in the CD4+ T-cell count less than 500 cells/μl group and 51 in the CD4+ T-cell count greater than 500 cells/μl group, who received either 2 doses of BNT162b2 (75%), mRNA-1273 (8.5%), or ChAdOx1 nCoV-19 (16.5%). It was found that patients with HIV with CD4+ T-cell counts fewer than 500 cells/μl and less than 200 cells/μl had considerably lower seroconversion rates and anti spike antibody titers vs the group who had a CD4+ T-cell count greater than 500 cells/μl group.