An experimental AIDS vaccine that’s worked better than anything else tried so far is going to be tested in South Africa, U.S. health officials said Wednesday.
They’ve tweaked the vaccine, which prevented infection by just about a third, and hope it will work better in this trial.
“For the first time in seven years, the scientific community is embarking on a large-scale clinical trial of an HIV vaccine, the product of years of study and experimentation,” said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID).
NIAID is part of the National Institutes of Health and a co-funder of the trial.
“A safe and effective HIV vaccine could help bring about a durable end to the HIV/AIDS pandemic and is particularly needed in southern Africa, where HIV is more pervasive than anywhere else in the world.”
There’s no cure for the human immunodeficiency virus (HIV) that causes AIDS, but cocktails of antiviral drugs can keep it under control — and if people take some of the same drugs they can protect themselves against infection.
That approach, called pre-exposure prophylaxis or PrEP can reduce the risk of catching HIV by 90 percent if people use it consistently. But it’s not cheap, and studies suggest it could be difficult for people in developing countries to stick to, if they could even get the drugs.
Most experts agree the best way to fight the virus — which infects 35 million people globally and which kills 1.2 million a year — would be to have a good vaccine.
“While we are making encouraging progress — new HIV infections have fallen by 35 percent globally since 2000 — the development of a safe and effective HIV vaccine would be the ultimate game-changer,” Fauci wrote in a blog post.
The experimental vaccine being tested in based on a U.S. military vaccine called RV144 that protected 31 percent of volunteers in Thailand in 2009.
“The design and schedule of the RV144 vaccine regimen have been adjusted to try to increase the magnitude and duration of vaccine-elicited immune responses,” NIAID said. “The trial is slated to begin in November 2016, pending regulatory approval.”
NIAID hopes to enroll 5,400 people who are not infected with HIV.
The vaccine used in Thailand has been modified to fight the South African strain of the virus, and seven years has been devoted to strengthening its efficacy.
HIV researcher Linda Gail Bekker, who was involved in testing the efficacy of the vaccine in South Africa on 100 people, said the results suggested that the modified vaccine might be “more potent and longer lasting” than the vaccine tested in Thailand.
Anthony Fauci, director at the US National Institutes of Health, a co-funder of the trial, said the vaccine was “the product of years of study and experimentation”.
“A safe and effective HIV vaccine could help bring about a durable end to the HIV/Aids pandemic and is particularly needed in Southern Africa, where HIV is more pervasive than anywhere else in the world.”
The Medicines Control Council and scientists have discussed the level of protection that the vaccine must give if it is to be approved by regulators.
The vaccine is not expected to be 100% effective. Scientists want to use it in conjunction with male circumcision and other HIV-prevention methods, such as treating infected people, in an attempt to lower the rate of new infections. About 1000 South Africans are infected with HIV every day.
Mitchell Warren, director of NGO AVAC, said even a partially effective vaccine could significantly decrease the infection rate over decades.
Warren said that a vaccine that would reduce the risk of contracting HIV by 70% and lasted for five years “would reduce annual new infections by 44% over the first decade, by 65% in the first 25 years and by 78% to 122000 in 2070”.
“We don’t know if the vaccine being trialled in South Africa will be as effective as this but the modelling does confirm that a partially protective vaccine would have significant impact.”
South Africa has about 6.4million people with HIV – the highest incidence in the world – and it has the world’s biggest treatment programme with 3.2million people on antiretrovirals and there are plans to expand this by 300000 a year.
An extra R1-billion has been set aside to increase access to treatment.
Deputy director of Wits Reproductive Health and HIV Institute Francois Venter said: “Having something that doesn’t have to be carried in your pocket or used during sex, and which is permanent, would be a huge benefit.”
Source: TimesLIVE, Facebook, NIAID