Patients receiving highly active antiretroviral treatment (HAART) for advanced AIDS should be able to benefit from future vaccines delivered mucosally to control the disease, as HAART restores homoeostasis of intestinal B cells, a long term study has confirmed.

Intestinal B cell activity during simple treatment for AIDS during 1991–6 was compared with activity during treatment with HAART two years subsequently and activity in healthy controls. HAART significantly reduced number of cells producing IgA per 500 μm length of duodenum (median number 112 v 181) and normalised the proportion producing IgG1when compared with no treatment or other treatments. It also increased CD4 cell number and lowered viral load. Immunocytes producing IgA, IGM, or total IgG were found in similar median proportions in the HIV positive patients and controls.

Duodenal biopsy and peripheral blood specimens were taken consecutively from 31 HIV-1 positive patients, mostly with advanced AIDS and all with various HIV associated infections, and from 11 age matched HIV negative healthy volunteers during 1991–8. The biopsy specimens were used to determine the number and type of mucosal antibody producing B cells by in situ two colour immunofluorescence staining, and the blood samples to determine amounts of retroviral RNA.

The ability of HAART to stabilise mucosal immunity, as it does systemic immunity, has been doubtful, owing to conflicting study results. This study suggests that HAART restores normal balance to mucosal immunity, making potential immunisation by the mucosal route a realistic prospect for AIDS patients.