What are Vaccines for HIV Prevention and Therapy?
Today there are no HIV vaccines which can prevent HIV infection. All of the candidates being studied are in the experimental stage. Preventive vaccine candidates are being tested in HIV-negative people. Some of these candidates are being tested to see if they can prevent infection. Other candidates are being tested to see if they lower viral load in people who receive the vaccine before becoming HIV infected but can learn to partially fight the resulting infection.
In 2014, global investments in preventive AIDS vaccine R&D increased by US$23 million, or 2.8 percent, from US$818 million in 2013 to US$841 million in 2014 (Figure 16). Funding in 2014 rebounded, despite the fact that 2013 saw the greatest year-to-year decrease in AIDS vaccine investment since 2008, following five years where funding had either declined or flatlined from a height of $961 million in 2007.
In 2013, mandated austerity measures taken by the US government caused a significant decline in funding. US sequestration policy mandated across-the-board budget cuts, affecting all aspects of the US fiscal environment in 2013 and not just HIV prevention research funding. While AIDS vaccine investments have yet to rebound to 2012 levels, 2014 saw a modest increase in investment over the previous year. While NIH investment did not return to 2012 levels, it did increase by US$14.5 million from 2013, and USAID funding increased by nearly US$1.4 million in 2014, regaining funding lost in 2013 due to sequestration (Figures 17 and 18).
Increases in funding from the US, the philanthropic-sector and commercial sector offset decreases by public-sector funders outside of the US. The philanthropic sector increased investment by US$10.5 million (13 percent) and commercial sector increased investment by nearly US$24 million (76 percent). Many public-sector agencies in Europe and other countries decreased their investment in 2014, including: Australia, Belgium, Canada, Denmark, EC, France, India, Japan and Thailand. Others increased their investment, including: Ireland, Italy, South Africa, Spain, Sweden, Switzerland and the UK.
Progress towards an AIDS vaccine advanced substantially in 2014, with new data on a variety of strategies. Just a few of the advances include:
- In December 2014, the Ad26 vector combined with mosaic modified vaccinia virus Ankara (MVA) boost vaccine started in a Phase I/II trial. Sponsored by Janssen, the trial is a partnership between the US NIH, US Military HIV Research Program (MHRP), International AIDS Vaccine Initiative (IAVI) and the Beth Israel Deaconess Medical Center in the US. In 2015 the trial will open in Rwanda, South Africa, Thailand and Uganda.
- The Pox-Protein Public-Private Partnership (P5) is funding a follow-up to the RV144 trial in Thailand, in which a similar pox-protein vaccine regimen was shown to reduce the risk of HIV infection by 31.2 percent. RV-144 follow-on trials are underway in Thailand. Additional P5 trials of attenuated vaccine candidates are underway and planned, starting in 2015 in Southern Africa. Organizational and financial support for the P5 comes from NIAID, the Bill & Melinda Gates Foundation, the US MHRP, Sanofi Pasteur, Novartis Vaccines and Diagnostics and the South African Medical Research Council in humans.
- Preclinical data on broadly neutralizing antibodies showed effectiveness in preventing infection in monkeys, and also showed evidence of therapeutic benefits. New target sites for neutralization and the isolation of even more powerful neutralizing antibodies were identified in 2014. The NIH supported clinical studies of passive immunization studies of broadly neutralizing antibodies, and a vectored immunoprophylaxis trial led by IAVI began in 2014.