Research addresses challenges for future HIV vaccine

University of TorontoJul 15 2010

On the eve of the world's biggest AIDS conference this month in Austria, a new research review shows many people wouldn't get inoculated against HIV even if a vaccine was developed.

The authoritative review - published in this month's edition of the journal AIDS - was led by Peter A. Newman, associate professor at the University of Toronto's Factor-Inwentash Faculty of Social Work. Newman and PhD candidate Carmen Logie drew conclusions from 30 previous research papers involving nearly 12,000 people on the topic of HIV vaccine acceptability.

"One might assume that if an HIV vaccine was available, many people would line up to be vaccinated. However, the research strongly indicates this is not the case," says Newman, Canada Research Chair in Health and Social Justice. "The availability of a vaccine alone is not enough to ensure that people will be inoculated."

Newman and Logie's meta-analysis of existing literature identified several factors that could influence people's willingness to be inoculated with an HIV vaccine. Among them:

• The effectiveness of a vaccine: The research showed people would be far less likely to take an HIV vaccine if it was only 50 per cent effective in protecting against HIV infection:
  • If a vaccine was 50 per cent effective in protecting against HIV, only 40 per cent of people said they would accept it
  • If a vaccine was 100 per cent effective, 74 per cent of people said they would accept it

• Risk perception: The research showed many people do not see themselves as being "at risk" of contracting the disease - even if they are - and so would not consider being inoculated against HIV.

• Structural factors: The research showed that factors such as cost and access to vaccines would prevent some people from seeking inoculation.

Additional but less influential factors included fear of side effects and fear of vaccines.

"If we want a future HIV vaccine to be acceptable and accessible to people, we need to address these factors now, before the vaccine is publicly available," says Newman. "Otherwise, we'll get to the point where we've got a safe and reasonably effective vaccine but the public is not prepared or able to receive it."

Logie says the research indicates a growing need for public education. People need to understand what scientists mean when they talk about a vaccine's efficacy, she says.

"The research shows that some people are highly suspicious of vaccines that are less than 100 per cent effective, but the fact is, not every vaccine is 100 per cent effective. That's something the public needs to understand," she says.

There must be more education and awareness around the benefits of vaccines and the continuing risk of HIV, particularly in young people, says Newman. "It's a challenge to have people weigh the very miniscule risks of getting a vaccine against the far greater risks of HIV." And governments need to consider what can be done to address "structural barriers" such as cost for vaccines and making them easily accessible.

"The research has clearly identified factors that would influence people's decisions around HIV vaccinations," says Newman. "Now, we have to ask ourselves, 'which of those factors can we begin to address, and how?'"