First human trials for new HIV vaccine

Doctors who have developed a new HIV vaccine at a London hospital say they are “optimistic” that it will ultimately lead to full immunisation against the virus.

The team at the Royal Free Hospital have created antibodies against the virus in rabbits and are now poised to carry out the first trials with humans.

Healthy women aged between 18 and 55 will be monitored for eight months after taking the vaccine to ensure it is safe and induces an immune response. If the trials are successful, a wider “efficacy study” will be carried out in a country with high HIV infection rates before the vaccine can be approved and licensed. Most experiments aimed at finding an HIV vaccine have focused on producing T-cells, or killer cells, in the body to try to wipe out the infection. This has been difficult because of the ever-changing nature of the virus.

The only success came in a US-backed trial in Thailand in 2009 which found that a combination of two vaccine prototypes derived from a weakened version of the common cold was 30 per cent effective in preventing infection.

But the new EN41-UGR7C experimental vaccine does not involve any kind of delivery “vector” such as flu. Dr Sabine Kinloch, who developed the vaccine with Professor Margaret Johnson, clinical director of HIV/Aids at the Royal Free, said: “Here we are using just one product and it does not have a vector, we are just using part of a protein envelope that is in a lot of HIV in the world.

“We are looking to produce antibodies against the virus at the portal of entry — just at the very precise moment when the virus is about to get into the cells — and stop it before it gets in.” They chose the protein as it can be produced in large quantities very easily. Their research is part of a five-year grant programme called Eurovac.

Dr Kinloch said these were “exciting times”. Results from the human tests will be analysed in Strasbourg and scrutinised before any efficacy study.

There are 31 million people around the world with HIV.

Dr Michael Brady, medical director at Terrence Higgins Trust, said: “Vaccines in HIV have been very disappointing. So anything that works in a different way could be pretty exciting.”