Stigma affects 20% of HIV vaccine trial participants

There is a need for better strategies to counter the negative social reactions experienced by participants in HIV vaccine trials, report researchers in the November issue of the Journal of Acquired Immune Deficiency Syndromes. Future trials, they conclude, should strive to protect the privacy of participants and to continue fighting the general public’s misconceptions surrounding HIV vaccines.

A preventative vaccine that protects against HIV is a much sought weapon in the fight against HIV. Despite several attempts, it remains frustratingly elusive. The world’s first large-scale phase III vaccine trial was conducted from 1998 to 2002 and raised the hopes that an effective vaccine was within reach. The findings from the Vax004 trial were disappointing. The study, which tested the AIDSVAX B/B in a multi-centre randomised placebo-controlled trial of over 5000 participants in North America and Europe, showed no difference in infection rates between those vaccinated and those receiving placebo injections.

In the substudy presented here, Jonathan Fuchs and colleagues analysed the responses to a semi-annual, interviewer-led questionnaire that probed for what the researchers termed negative social impacts (NSIs). NSIs encompassed a range of non-medical negative events experienced by participants, including unintentional disclosure and problems with personal relationships, employment, insurance, housing, medical care or travel.

Upon analysis, a total of 973 (18%) of the trial’s 5417 participants reported a total of 1496 such events, with 146 (3%) reporting more than one event. Most of the events occurred within the first six months.

The most common NSI was negative reactions from friends, family and partners, reported by 785 (14%) of the study participants. These reactions primarily stemmed from two misunderstandings. First, others often believed the participant was at risk for being infected by the vaccine or that the vaccine was unsafe. Second, others sometimes believed that they themselves were at risk for infection if they were exposed to vaccinated participants.

When researchers asked a subset of the participants reporting these events to rate the impact of the event on their quality of life, the large majority (93%) of these events were considered to have a mild or moderate impact.

The second most common NSI was unwanted or unintentional disclosure of participation, reported by 176 (3.2%) of study participants. Events often included the participant being seen at the study clinic or others finding study material in the participant’s home.

Other issues, such as events impacting employment or insurance, were each reported by less than 1% of participants. However, participants often rated the impact of these events as moderately upsetting or a major disturbance. Events included participants who believed their participation in the study had led to job termination or the denial of health or life insurance. Actual vaccine-induced antibody results were not implicated in any of the insurance events. The requirement for HIV testing also stopped some participants from applying for insurance or joining the military.

The researchers then analysed their data to identify factors that might make an NSI report more likely. Among men, reports were more likely to come early in the study (within the first six months) and from men enrolled at sites with fewer than 50 participants. Younger men and men who had more than one sexual partner in the last six months were also more likely to report an NSI.

The researchers also found that men participating at sites in areas with relatively high cumulate AIDS case rates were more likely to report an NSI. This finding contradicted the researchers’ hypothesis that participants living in centres with high AIDS burdens would experience fewer NSIs because of an increased general knowledge of AIDS. To explain their results, the researchers speculated that in these high burden centres, participants might have felt reassured and thus more willing to disclose. Yet, they faced negative reactions from misinformed friends and co-workers.

Among women, NSIs were most likely to occur early in the trial and among women enrolled at sites with fewer participants. The authors note that the small sample size of female participants (309) limited the power of any statistical analysis to identify relevant predictors.

In conclusion, the researchers hope that their findings may inform future vaccine trials and decrease NSIs experienced by participants. They put forward several recommendations, including increased education of the general population to counter misconceptions around HIV vaccines and increased education of trial participants about the possibility of experiencing an NSI and how to respond to it.