Pneumococcal vaccination in people living with HIV.

Streptococcus pneumoniae is the leading bacterial opportunistic infection (OI) in HIV positive individuals. Anti-retroviral treatment (ART) reduces their risk of Invasive Pneumococcal Disease (IPD), however, it remains 20- to 40-fold greater than that of the general population. In HIV-infected adults, pneumococcal vaccination (PCV) induces more durable and functional antibody responses in individuals on ART at the time of vaccination than in ART-naive adults, independently of the baseline CD4+ cell count. National guidelines in the UK recommend vaccination in HIV-infected adults with CD4 count >200cells/mL and advise that it be considered for those with CD4 count <200cells/mL(3). We report data on IPD from a London HIV cohort of 3500 north-east London patients from 2009 to 2012. IPD was defined as a positive pneumococcal culture from blood, CSF, joint aspirate or pericardial fluid. HIV positive cases were identified by cross-referencing hospital identifiers with a positive HIV Ab/Ag test result or HIV viral load test result on the virology database. There were a total 189 cases of Invasive Pneumococcal Disease identified over the three years. 4.8% (n=9) were known to be HIV positive at the time of their Invasive Pneumococcal infection. The serotypes of S. pneumoniae in the HIV positive cases included 3, 7F, 10F, 19A (n=2), 19F and 31. The estimated incidence of IPD in our HIV cohort was 85.7 per 100,000, (based on an overall HIV cohort size of 3500) which is significantly higher when compared to the general population in London (local epidemiological data reported the incidence rate for IPD at 7.5 per 100,000 in London). Given the higher burden of Invasive Pneumococcal Disease in this cohort, low levels of vaccination, and the predominance of vaccine sensitive strains in our cases, vaccination and strategies to improve vaccine uptake is a priority in this at risk group.