AIDS vaccine clinical trials

In excess of 40 million individuals are now thought to be infected by HIV. In 2001 alone, it was estimated that 3 million people died from AIDS and a further 5 million became infected with the virus. Over 20 million people in total are now thought to have died from AIDS. The worst affected geographical region is the southern half of Africa (Table 13.11). Some 90 per cent of sufferers live in poorer world regions. So far, no effective therapy has been discovered, and the main hope of eradicating this disease lies with the development of safe, effective vaccines. The first such putative vaccine entered clinical trials in 1987 but, thus far, no effective vaccine has been developed. 

Plasma-derived hepatitis B virus vaccine is prepared from the plasma of chronic HBsAg carriers, and consists of purified, inactivated 20-nm HBsAg particles adsorbed on to an aluminium adjuvant. The use of a vaccine produced with plasma derived from infected individuals represented a major departure from conventional approaches, and safety testing has therefore been designed to cover all possibilities of risk and to ensure freedom from transmission of residual HBV and other blood-borne agents. Various clinical trials (SEDA-10, 289) (SEDA-11, 289) have confirmed the safety of plasma-derived hepatitis B virus vaccines produced by different manufacturers. Fears that plasma-derived vaccine may transmit AIDS can be considered unfounded. 

Edelman R. An update on vaccine adjuvants in clinical trial. AIDS Res Hum Retroviruses 1992 8(8) 1409-11. 

Levin MJ, Gershon AA, Weinberg A, Blanchard S, Nowak B, Palumbo P, Chan CY AIDS Clinical Trials Group 265 Team. Immunization of HIV-infected children with Varicella vaccine. J Pediatr 2001 139(2) 305-10. 

Recent reviews Hst more than 400 biotechnology-based pharmaceutical formulations either registered in clinical trials or undergoing review by the regulatory agencies for the treatment of nearly 150 diseases including cancer, infectious diseases, autoimmune diseases, and AIDS/HIV (1,2). Biotechnology-based pharmaceuticals already on the markets include recombinant blood factors, recombinant hormones, cytokines, vaccines, monoclonal antibody-based products, and therapeutic enzymes. 

While the search for an effective AIDS vaccine continued with little or no success, pharmaceutical companies flourished by designing drugs that would inhibit retroviruses. By 1996 there were 16 drugs used to inhibit either the HIV reverse transcriptase or the protease, some of which we have seen before, such as AZT and saquinavir. Several others are in clinical trials, including drugs that target the gp41 and the gpl 20 in an attempt to prevent entry of the virus. Table HIV-1 shows... 

Note Data extracted from listed vaccine projects in the year 2000 [1] without consideration of AIDS vaccine projects. Vaccine projects in Phase III clinical trials for new indications include vaccines against Coccidioides immitis, group B streptococcus, Streptococcus pneumoniae, Plasmodium falciparum, Trypanosomsa cruzi, Leishmania major, Mycobacterium leprae, Meningococcus B and C, Rotavirus, and Vibrio cholerae. 

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