Avian Flu Update
Antibodies may be key to treatment

Adults who have recovered from the potentially deadly H5N1 strain of avian influenza may hold the key to future treatments for the virus, according to an international team of researchers. In a study published in the open access journal PLoS Medicine, the researchers have shown how specific antibodies taken from avian flu survivors in Vietnam can be reproduced in the laboratory and prove effective at neutralising the virus in vitro and in mice.

Doctors based at the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam, the Institute for Research in Biomedicine in Bellinzona, Switzerland and the National Institute of Allergy and Infectious Diseases in Bethesda, US, have shown that monoclonal antibodies generated from blood of human survivors of the H5N1 virus are effective at both preventing infection in mice and neutralising the virus in those already infected. The research had been fasttracked for funding by the UK’s Wellcome Trust and is also supported by grants from the National Institutes of Health in the US and the Swiss National Science Foundation.

The researchers found that the antibodies provided significant immunity to mice that were subsequently infected with the Vietnam strain of H5N1. This reduced significantly the amount of virus found in the lungs and almost completely prevented the virus reaching the brain or spleen. In those people in Vietnam who died from the H5N1 strain, the virus was found to have spread from the lungs; this was not the case in those who survived.

“We have shown that this technique can work to prevent and neutralise infection by the H5N1 ‘bird flu’ virus in mice,” says Dr Cameron Simmons, a Wellcome Trust researcher at the Oxford University Clinical Research Unit, Vietnam. “We are optimistic that these antibodies, if delivered at the right time and at the right amount, could also provide a clinical benefit to humans with H5N1 infections.

“In particular, we found that it was possible to administer the treatment up to 72 hours after infection. This is particularly important as people who have become infected with the virus do not tend to report to their local healthcare facilities until several days after the onset of illness.”

ARV drug prices lowered significantly

Former US president Bill Clinton in May announced new agreements that significantly lower the price of AIDS treatment for secondline anti-retroviral drugs (ARVs), drugs required in patients who develop resistance to first-line treatment and which currently cost 10 times the price of first-line therapy. These agreements lower the prices for 16 formulations of ARVs that will generate an average savings of 25% in lowincome countries and 50% in middle-income countries. Reduced prices will be available to 66 developing countries in Africa, Asia, Latin America and the Caribbean through the Clinton Foundation’s Procurement Consortium.

Citing the importance of keeping AIDS treatment affordable, President Clinton also announced the “next generation” first-line treatment, taken once daily, is now less than $1 under new agreements. The equivalent product in the US, launched in July 2006, is widely perceived as a goldstandard treatment, as it offers greater convenience, fewer side effects, and improved treatment outcomes in comparison to the regimen used most commonly in developing countries.

“Seven million people in the developing world are in need of treatment for HIV/AIDS,” said Clinton. “We are trying to meet that need with the best medicine available today, and at prices that low and middle income countries can afford. I applaud [generic drug manufacturers] Cipla and Matrix for their commitment to lower the cost of new drugs at the forefront of the fight against AIDS, and I thank UNITAID for the funds that have enabled us to make these drugs widely available.”

Clinton was joined at the announcement by Thailand Minister of Health Mongkol Na Songkhla and Kenyan Minister of Health Charity Ngilu, who both praised the Clinton Foundation for its efforts that have given Thailand, Kenya and dozens of other countries the opportunity to expand lifesaving treatment and give thousands of people a chance at life.

UNAIDS and the Global Fund have come out in support of the new agreements.

“It can be hard to take AIDS drugs properly, and even when people do, they develop resistance over time, and need new medication,” said Michael Kazatchkine, executive director of the Global Fund to Fight AIDS, TB and Malaria. “Today’s announcement means progress on both: lower prices for state of the art once a day combinations, and lower prices for secondline treatment. Thanks to the Clinton Foundation and UNITAID, developing countries and the Global Fund won’t have to choose as much between continuing treatment for people who need new drugs, and putting new people on treatment. This means programs supported by the Global Fund will be able to save more lives.”