[Vaccines against HIV/AIDS].

Area of Science:

• Immunology
• Vaccinology
• Virology

Context:

• Over 50 HIV/AIDS vaccine trials have occurred since the 1980s, involving over 16,000 volunteers.
• Envelope-based vaccines targeting neutralizing antibodies have shown limited success, with a gp120-based vaccine failing in Phase III trials.
• CD8+ T-cell responses are crucial for controlling simian immunodeficiency virus (SIV) in animal models.

Purpose:

• To explore the development of HIV vaccines that induce T-cell responses, shifting focus from infection prevention to disease control.
• To review current vaccine candidates, including live viral vectors (ALVAC, Ad5, MVA) and other platforms tested in nonhuman primates.
• To evaluate the potential of T-cell stimulating vaccines in managing HIV/AIDS, even if they cannot prevent initial infection.

Summary:

• Candidate HIV vaccines based on live viral vectors (canarypox, adenovirus, vaccinia) are in various clinical trial phases.
• Nonhuman primate models show that while vaccines may not prevent SIV infection, they can reduce viral loads and preserve CD4+ T-cell counts.
• T-cell stimulating vaccines represent a new approach, aiming to control disease progression rather than achieve complete prevention.

Impact:

• The development of T-cell stimulating vaccines offers a new paradigm for HIV/AIDS management, focusing on controlling the disease.
• Further clinical trials are necessary to establish the efficacy of these novel vaccine strategies in humans.
• This research highlights the potential for vaccines to manage chronic viral infections by controlling viral replication and disease progression.