Remune, previously known as HIV Immunogen, is a therapeutic vaccine preparation. Unlike the other vaccine preparations under study, which consist of individual viral proteins, remune is made from whole HIV particles, which have had their envelope layer stripped off and have been made harmless by chemical and radiation sterilisation. The inactivated HIV is mixed with a mineral oil called incomplete Freund’s adjuvant in the final formulation.

It is hoped that injecting these particles into the people who are already infected with HIV will stimulate the immune system to mount a greater immune response not only to the killed HIV particles but also to real virus particles and HIV-infected cells. Because it is based on whole inactivated virus, this vaccine could stimulate broader immune responses that are capable of suppressing more diverse HIV strains than vaccine preparations based on single subunit proteins of the virus.

Remune was developed by Jonas Salk, discoverer of the polio vaccine, and is now being developed by the Immune Response Corporation. It is sometimes referred to as the Salk vaccine.

Agouron Pharmaceuticals was collaborating with the Immune Response Corporation on the development and testing of remune. However, in August 2001, Agouron terminated the collaboration when a key clinical trial failed to demonstrate the benefits of remune.

Optimism about remune was dampened by a large phase III study, which failed to find any additional benefit from remune when added to anti-HIV therapy. The trial was halted due to the low rate of disease endpoints and the lack of difference between patients randomised to Remune and to placebo^[1]. Following the disappointing results from Study 806, the future of other clinical endpoint studies involving Remune was questioned. The Immune Response Corporation announced that it would not proceed with Study 802, because the unexpectedly low number of people experiencing virological failure made meaningful analysis of the statistics impossible.

That Remune failed to show effectiveness in this study may be a function of limited understanding of the immune system and a result of the impact of anti-HIV drugs. A meeting of the United States Food and Drug Administration agreed that immune-based therapies should not be expected to have the same impact on viral load and CD4 cell counts as antiviral treatments. In addition, they stated that assessing the long-term impact of immune-based therapies may be difficult in the context of antiretroviral therapy, given the lack of understanding about the workings of the immune system.

Despite the disappointment of this study, several studies have found that remune may have some immunological and virological benefits. One comparative study of 252 people on antiretroviral therapy found that people taking remune had a greater reduction in viral load, a trend towards a greater CD4 cell count increase and superior HIV-specific immune responses^[2]. Although the randomised Spanish STIR 2102 trial failed to show a benefit of remune when added to antiretroviral therapy in terms viral load and CD4 cell count, further statistical analysis found that remune protected against virological rebound compared with placebo^[3][4].

Remune monotherapy has also shown promising results in an observational Thai study of 223 patients taking remune before starting antiretroviral therapy. After over two years of treatment, patients taking remune had a lower rate of disease progression, higher CD4 and CD8 cell counts and higher body weight^[5]. Remune has also been shown to increase anti-HIV responses of the immune system to levels higher than those seen in long-term non-progressors. These have been correlated with very low viral load and immune preservation^{[6][7][8][9][10]}.

Ongoing research includes a phase II study comparing the addition of remune or placebo to AZT (zidovudine, Retrovir), 3TC (lamivudine, Epivir) and indinavir (Crixivan) among people with CD4 cell counts greater than 400 cells/mm³, and a phase I open-label trial among HIV-positive children.

Remune is administered by injection into the muscles every twelve weeks. No side-effects have been reported.