RESPONSE TO INFLUENZA-VIRUS VACCINATION IN VERTICAL HIV-INFECTION

Objective-To assess the antibody response to influenza vaccine of chil dren vertically infected with HN. Design-Prospective study in HIV infe cted children vaccinated during the winter of 1994-5. Setting-Family H IV clinic at St Mary's Hospital, Paddington. Subjects-25 children, age d 1-11 years, vertically infected with HIV. Main outcome measures-Resp onses to influenza antigens (H1N1-A/Taiwan/1/86, H3N2-A/Shandong 19/93 , B/Panama/45/90) were tested by haemagglutination inhibition. Antibod y responses were assessed according to clinical symptoms and immune fu nction, stratified according to the 1994 revised classification for HI V infection in children. Results-23 children (92%) had either very low or no detectable antibody before vaccination. New protective antibody responses were made by 10 children (40%): in seven to a single antige n, in two to two antigens, and in one to all three antigens. For each antigen there was an overall small increase in the mean geometric titr e of antibody produced, but this only reached a protective level for a ntigen H1N1 and for children with minimal symptoms. Less symptomatic c hildren were significantly more likely to produce a protective antibod y response to influenza vaccination. No association was found between immune function, as measured by CD4 count, and vaccine response. Concl usions-Only vaccination of the least symptomatic HIV infected children against influenza is likely to be effective. This will not only prote ct them against influenza, but will also protect other more immunosupp ressed and vulnerable members of their families.