Antibody responses to trivalent influenza vaccine in Iranian adults infected with human immunodeficiency virus.

The serious influenza-associated complications among immunodeficient individuals such as those who are infected with human immunodeficiency virus (HIV), highlights the importance of influenza vaccination in these people. Therefore, the current study aimed to investigate the antibody responses to influenza vaccine in this group. Two hundred subjects were recruited, during autumn 2010 and 2011, to receive, trivalent inactivated influenza vaccine consisting of A (H1N1), A (H3N2), and B strains. Hemagglutination inhibition assay was used to measure the antibody titer against all strains of the vaccine prior and one month post vaccination. Seroconversion rate for A (H1N1), A (H3N2), and B were found to be 58.5%, 67% and 64.5%, respectively. No correlation was found between antibody titer and demographics factors such as age and gender; however, we found a significant correlation between antibody titer and CD4 cell count. Checking the local and systemic reactions after vaccination, the pain on the injection site and myalgia were the most common local and systemic reactions with 20% and 6.5%, respectively. As vaccination with influenza mount considerable antibody responses in HIV-infected patients, annual influenza vaccination seems to be rational in order to prevent or reduce the severe clinical complications induced by influenza virus.