HIV study seeks volunteer couples to help find new vaccine

Researchers encourage couples with one HIV-positive and one HIV-negative partner to take part in research - News Release

Imperial College London News Release

For immediate release
Friday 30 November 2007

London doctors are seeking couples where one partner is HIV-positive and the other is HIV-negative, to take part in a new global study to discover how some people remain uninfected with HIV despite exposure to the virus.

The research, launched today on the eve of World AIDS Day, is part of an international programme that will see scientists, clinicians and volunteers across the world working together with the ultimate aim of creating a new vaccine against HIV.

The researchers, from Imperial College London and King's College Hospital NHS Foundation Trust, are looking for couples where one partner has remained HIV-negative, in spite of having been exposed to HIV through unprotected sexual contact with their HIV-positive partner. The researchers are encouraging both heterosexual and homosexual couples, who have been together for a year or more, to volunteer to take part. They are also seeking monogamous HIV-negative couples who sometimes have unprotected sex, to act as controls.

The clinics for volunteers are based at the St Mary's Hospital campus of Imperial College, in West London, and at King's College Hospital in South London. The two London research centres are the only UK sites for the worldwide CHAVI (Center for HIV-AIDS Vaccine Immunology) study, which is funded by the US National Institute for Allergy and Infectious Diseases.

By conducting detailed analyses of blood samples from the volunteer couples, the researchers are hoping to uncover whether there are differences in the naturally occurring immune responses in these rare, seemingly protected, individuals who have not become infected with HIV in spite of exposure to the virus. Their research will investigate both the innate and cellular arms of the immune system. If specific protective immune responses can be identified in these individuals, it may be possible to develop a vaccine against HIV which works by replicating this immunity in others.

A limited number of studies in Kenya, the UK and the USA have already identified similar groups of people, including one which looked at a group of sex workers in Nairobi who have escaped infection in spite of multiple exposures to HIV. However, these studies were inconclusive in terms of defining the role of the individuals' immune systems in helping them avoid infection.

Researchers hope that the new large programme of studies, which will look at different groups of similarly exposed but uninfected people across the world, will give a much more in-depth picture, and provide much more detailed immunological information, than ever before.

Dr Sarah Fidler, one of the researchers on the study from the Division of Medicine at Imperial College, said: "We would strongly urge everyone to practice safe sex to avoid HIV infection. However, sex with a person infected with HIV does not always lead to the virus being passed on to the uninfected partner. Working out why transmission doesn't occur in a very small number of cases could be the key to creating a vaccine to prevent others becoming infected. We need to work out whether these people have not yet caught the virus because of sheer chance, or whether there is a difference in their makeup which somehow is helping them to avoid infection."

HIV research suffered a major setback in September of this year when trials of a potential vaccine had to be halted after the discovery that it neither prevented HIV infection, nor lessened the amount of virus in those who became infected. Merck's MRKAd5 trivalent vaccine aimed to stimulate production of T-cells in the immune system in order to kill HIV-infected cells.

"We would encourage any couples who feel that they can spare the time to join us in our search to develop the understanding that we hope will lead towards the development of a successful protective HIV vaccine. The recent disappointing termination of the Merck vaccine trial and the lack of an effective vaccine to date despite enormous research initiatives has lead the field once more to return to these rare, invaluable individuals who could hold the key to understanding the factors capable of conferring protection against HIV infection," added Dr Fidler.

Thirty three million people worldwide are estimated to be infected with HIV. Recent Health Protection Agency (HPA) figures for the UK, released in November 2007, suggest that 7,093 people were newly diagnosed with HIV in 2006, including 2,700 gay men. HPA reports also suggest that London still accounts for the highest number of newly diagnosed cases of HIV in the UK. The INSIGHT study in 2004 showed that there appears to be a level of complacency about HIV, especially amongst young gay men living in London who no longer express major concern at the risk of acquiring HIV infection.

Volunteers who would like to take part in the new trial will need to answer some questions about their relationship and provide blood and urine samples. Participants will be reimbursed for their time and transport costs. People wishing to take part should call freephone 0800 587 4406, email chavi@imperial.ac.uk or visit the website www.st-marys.nhs.uk/chavi.html. All enquiries will be treated in the strictest confidence.

-ends-

For further information please contact:

Laura Gallagher
Press Officer
Imperial College London
e-mail: l.gallagher@imperial.ac.uk
Telephone: +44 (0)207 594 6702 or ext. 46702
Out of hours duty Press Officer: +44 (0)7803 886 248

Bernadette Wilson-Govind
Head of Media
King's College Hospital Hospital NHS Foundation Trust
e-mail: bernadette.w-govind@kch.nhs.uk
Telephone: +44 (0) 20 3299 3006
Fax: +44 (0) 20 3299 3207

Notes to editors:

1. CHAVI

CHAVI is currently one of two implementation projects under the Global HIV Vaccine Enterprise, the other being the recently funded Collaboration for AIDS Vaccine Discovery (CAVD) by grants from the Bill and Melinda Gates Foundation. In July 2005, the US National Institute for Allergy and Infectious Diseases awarded the CHAVI grant to a consortium of investigators from Duke University, the Dana-Farber Cancer Institute, Beth Israel Deaconess Medical Center, Oxford University, and the University of Alabama-Birmingham. Website: www.chavi.org

2. Rated as the world's fifth best university in the 2007 Times Higher Education Supplement University Rankings, Imperial College London is a science-based institution with a reputation for excellence in teaching and research that attracts 11,500 students and 6,000 staff of the highest international quality.

Innovative research at the College explores the interface between science, medicine, engineering and ma nagement and delivers practical solutions that improve quality of life and the environment - underpinned by a dynamic enterprise culture.

With 66 Fellows of the Royal Society among our current academic staff and distinguished past members of the College including 14 Nobel Laureates and two Fields Medallists, Imperial's contribution to society has been immense. Inventions and innovations include the discovery of penicillin, the development of holography and the foundations of fibre optics. This commitment to the application of our research for the benefit of all continues today with current focuses including interdisciplinary collaborations to tackle climate change and mathematical modelling to predict and control the spread of infectious diseases.

The College's 100 years of living science will be celebrated throughout 2007 with a range of events to mark the Centenary of the signing of Imperial's founding charter on 8 July 1907. Website: www.imperial.ac.uk

St Mary's Hospital in Paddington is part of Imperial College Healthcare NHS Trust, formed on 1 October 2007 by the merger of St Mary's NHS Trust and The Hammersmith Hospitals NHS Trust, in partnership with Imperial College London. The resulting organisation is the UK's largest acute trust and first academic health science centre, integrating patient care with world-class biomedical research and medical education.

3. About King's College Hospital

King's College Hospital NHS Foundation Trust is one of the UK's largest and busiest teaching hospitals, with over 5,000 staff providing around 700,000 patient contacts a year. King's has a unique profile, with a full range of local hospital services for people in the London boroughs of Lambeth and Southwark as well as specialist services to patients from further afield. The Trust is recognized internationally for its work in liver disease and transplantation, neurosciences, cardiac and haemato-oncology. King's also plays a key role in the training and education of medical, nursing and dental students with its academic partner, King's College London. For more information, visit www.kch.nhs.uk