We have a lot more to learn before we can halt the AIDS pandemic

May 23, 2000

Vaccines work simply by producing antibodies, right? Well, probably not. And this misconception coupled with basic ignorance of how they do work is stalling the urgent quest for an AIDS vaccine, claim leading HIV researchers. They say no one has bothered to find out how highly successful vaccines like polio, measles and hepatitis B actually protect people from disease.

"I'm amazed by the amount of basic science we don't know," Philippe Kourilsky, director of the Paris-based Pasteur Institute, told the meeting: "We've had many successful vaccines over the past decades but we've missed a chance to see how these vaccines work. Each time a vaccine works the scientific community wanders off and leaves it to the public health workers to use it-and fails to invest in the research. If we had done that we would have been in a much better position to tackle the AIDS vaccine problem."

The assumption that successful vaccines work by simply producing antibodies is almost certainly wrong, Neal Nathanson, director of the US Office of AIDS Research, warns. "Hepatitis B vaccine is a good example. It's amazingly effective but no one knows how it works. And what's really interesting is it does work, even though HBV is a persistent infection-like HIV."

The vaccine probably stimulates some protective effect relying on killer T cells. But no one knows how it does it or what exactly the process is-even though the vaccine has been widely used for nearly ten years. It's a similar story for other highly successful vaccines including polio, measles and smallpox, he says. Ruth Ruprecht, a vaccine researcher and professor of medicine at Harvard Medical School, points out it's hard to get funding to research vaccines that already exist. "I always run into prejudice," she told New Scientist. "They say: 'It's old. What good is it?'"

Even if researchers can plug these huge gaps in their basic understanding, they may face another obstacle in their pursuit of an AIDS vaccine. Inducing antibodies against HIV might, in the initial stages of infection, do more harm than good, claims Ron Montelaro of the University of Pittsburgh.

His studies of a HIV-related virus that infects horses, known as the equine infectious anaemia virus, appears to confirm that the antibodies which initially respond to an infection can help spread the viruses around the body. Some vaccines designed to protect horses from infection make them die more quickly than unvaccinated horses, he found.

This process, whereby antibody production helps rather than hinders infectious agents, has been dubbed "enhancement". Montelaro suggests that these early enhancing antibodies actually help pull virus particles into the cells they are trying to infect. "It's an issue people haven't wanted to think about. But we might have to," he says. Jay Levy of the University of California at San Francisco, agrees: "Efforts to avoid these harmful consequences of HIV immunisation must be given a high priority."
-end-
Michael Day reports from the Pasteur Institute meeting in Paris.

New Scientist issue: 27th March 2000

PLEASE MENTION NEW SCIENTIST AS THE SOURCE OF THIS STORY AND, IF PUBLISHING ONLINE, PLEASE CARRY A HYPERLINK TO: http://www.newscientist.com




New Scientist

Related HIV Articles from Brightsurf:

BEAT-HIV Delaney collaboratory issues recommendations measuring persistent HIV reservoirs
Spearheaded by Wistar scientists, top worldwide HIV researchers from the BEAT-HIV Martin Delaney Collaboratory to Cure HIV-1 Infection by Combination Immunotherapy (BEAT-HIV Collaboratory) compiled the first comprehensive set of recommendations on how to best measure the size of persistent HIV reservoirs during cure-directed clinical studies.

The Lancet HIV: Study suggests a second patient has been cured of HIV
A study of the second HIV patient to undergo successful stem cell transplantation from donors with a HIV-resistant gene, finds that there was no active viral infection in the patient's blood 30 months after they stopped anti-retroviral therapy, according to a case report published in The Lancet HIV journal and presented at CROI (Conference on Retroviruses and Opportunistic Infections).

Children with HIV score below HIV-negative peers in cognitive, motor function tests
Children who acquired HIV in utero or during birth or breastfeeding did not perform as well as their peers who do not have HIV on tests measuring cognitive ability, motor function and attention, according to a report published online today in Clinical Infectious Diseases.

Efforts to end the HIV epidemic must not ignore people already living with HIV
Efforts to prevent new HIV transmissions in the US must be accompanied by addressing HIV-associated comorbidities to improve the health of people already living with HIV, NIH experts assert in the third of a series of JAMA commentaries.

The Lancet HIV: Severe anti-LGBT legislations associated with lower testing and awareness of HIV in African countries
This first systematic review to investigate HIV testing, treatment and viral suppression in men who have sex with men in Africa finds that among the most recent studies (conducted after 2011) only half of men have been tested for HIV in the past 12 months.

The Lancet HIV: Tenfold increase in number of adolescents on HIV treatment in South Africa since 2010, but many still untreated
A new study of more than 700,000 one to 19-year olds being treated for HIV infection suggests a ten-fold increase in the number of adolescents aged 15 to 19 receiving HIV treatment in South Africa, according to results published in The Lancet HIV journal.

Starting HIV treatment in ERs may be key to ending HIV spread worldwide
In a follow-up study conducted in South Africa, Johns Hopkins Medicine researchers say they have evidence that hospital emergency departments (EDs) worldwide may be key strategic settings for curbing the spread of HIV infections in hard-to-reach populations if the EDs jump-start treatment and case management as well as diagnosis of the disease.

NIH HIV experts prioritize research to achieve sustained ART-free HIV remission
Achieving sustained remission of HIV without life-long antiretroviral therapy (ART) is a top HIV research priority, according to a new commentary in JAMA by experts at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

The Lancet HIV: PrEP implementation is associated with a rapid decline in new HIV infections
Study from Australia is the first to evaluate a population-level roll-out of pre-exposure prophylaxis (PrEP) in men who have sex with men.

Researchers date 'hibernating' HIV strains, advancing BC's leadership in HIV cure research
Researchers have developed a novel way for dating 'hibernating' HIV strains, in an advancement for HIV cure research.

Read More: HIV News and HIV Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.