A candidate HIV vaccine developed in Russia is on the brink of starting phase II trials but could be stymied by a lack of funding, according to the researchers behind the project.
Valery Mikheyev of the Russian State Center of Virology and Biotechnology (Vector) based in Novosibirsk told a press briefing this week that the $5m-$7.5m in funding for the trial of CombiHIVvac still needs to be approved by the government, reports the RIA Novosti news agency.
The vaccine – which is synthetic and based on several DNA and protein HIV antigens or epitopes – is one of three candidates being developed by Russia’s state-funded scientific research institutions and has already cleared phase I trials started by Vector in 2010.
In preclinical studies, it was shown to induce an antibody and cytotoxic T lymphocyte (CTL) responses in mice, with antibodies that were deemed to be highly specific and are able to neutralise HIV-1 in vitro.
Mikheyev told reporters that the phase II trials planned for CombiHIVvac could take around two years to complete, provided funding can be found. It is “Russia’s only vaccine against AIDS to reach the second phase of clinical trials,” he added.
Efforts to develop an effective vaccine against HIV have so far proved fruitless, with a phase III programme for VaxGen’s AIDSVAX candidate ending in failure in 2004 and another study (NVTN 505) of a so-called ‘prime-boost’ vaccination approach dropped due to lack of efficacy in 2013.
To date, the only candidate showing any promise is RV144, which exhibited a modest level of protection in a Thai study reported in 2009 but needs additional research before it could be considered a vaccine candidate suitable for licensing.
The International AIDS Vaccine Initiative (IAVI) is supporting work on eight vaccines in total, but so far none have progressed beyond early-stage clinical testing.
Researchers are now studying the molecular structures of antibodies shown to have potent HIV-1-neutralising effects in a bid to reverse-engineer vaccines that might elicit similarly effective responses.