A seven-valent pneumococcal conjugate vaccine can protect adults with HIV against recurrent pneumococcal infection, according to research published in the March 4 issue of the New England Journal of Medicine.

Neil French, Ph.D., of the Malawi-Liverpool-Wellcome Trust Clinical Research Programme in Blantyre, Malawi, and colleagues analyzed data from 496 patients, aged 15 years and older, who had recovered from invasive pneumococcal disease. Most (88 percent) were HIV-positive. Subjects were given two doses of vaccine four weeks apart or placebo. The main end point was another episode of pneumococcal disease caused by a vaccine serotype or serotype 6A.

The researchers found that all episodes of disease were in individuals with HIV. Twenty-four patients developed episodes of pneumococcal disease caused by vaccine serotypes or the 6A serotype. Of these, 19 occurred in the placebo group and five occurred in the vaccine group, for a vaccine efficacy of 74 percent. Deaths weren't statistically different in the vaccine and placebo group (73 and 63, respectively).

"We have shown that HIV-infected adults can have a clinically relevant response to a pneumococcal conjugate vaccine, leading to protection against a common and serious co-infection. The ability of a conjugate vaccine to generate protective responses in patients with a low CD4+ count is of particular note and merits further study to elucidate the immune mechanisms involved and how such mechanisms may be used to produce other vaccines for this population," the authors write.