A So-So HIV Vaccine May Be a Hard Sell

October 7, 2010

A collection of studies shows that any HIV vaccine, while highly sought by doctors to battle the epidemic, would only be requested by some.

By Brad Wittwer
 
An HIV vaccine — the dream of medical science for a quarter-century — isn’t all that far off. Given that 2.7 million new HIV infections in 2008 alone brought the world total to 33.4 million infected, there is a genuine need.

But rather than a line out the door the first day of availability, new research by Peter Newman and Carmen Logie of the University of Toronto suggests that an HIV vaccine will mostly cause hypochondriacs to rush to their local clinic and others to, at best, scribble an appointment in the weekly planner.

The team gathered 30 original studies, mostly from North America but also from Africa and Southeast Asia, to analyze HIV vaccine acceptability. Selecting 20 studies involving 7,576 participants between 1996 and 2010, the researchers ranked HIV “vaccine acceptability” — how in demand a vaccine would be — on a 100-point scale for each study. Results ranged from 37.2 to 94.0, with the average being 65.3.

Not surprisingly, results varied depending on how effective the putative vaccine would be. Limiting the testing to 11 studies, acceptability was 73.8 for a high-efficacy vaccine (80-95 percent) versus 40.4 for a moderate-efficacy vaccine (50 percent).

The results “raise cause for concern given the likelihood that initial HIV vaccines may be of low to moderate efficacy,” the authors write.

Across studies, acceptance rose alongside vaccination efficacy, duration of protection and perception of being at risk and fell with concerns over side effects, cost, pragmatic obstacles, safety concerns, fear of vaccines and fear of needles. The perception that a vaccine would be very effective drastically increased expectations of use, while the idea that someone wasn’t in the “risk group” for HIV/AIDS infection significantly decreased use.

To overcome this wariness, the researchers propose educating people’s perceptions of susceptibility to be more accurate — most underestimate their current risk of infection by the virus but if educated, people would be more apt to request a vaccine as is warranted. They also propose subsidies to reduce costs — free transportation to clinics for example would be one.

The authors emphasize the need for more research, since roughly 75 percent of the studies were conducted in North America and not Africa, which has the highest rates of HIV infection. In different cultural and socio-economic settings, the factors that most affect vaccine acceptability may be altogether different. Cost and pragmatic factors like remote access will take on a new meaning in less-developed nations.

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