An update on human immunodeficiency virus vaccine preparedness studies

Exploring a community's understanding of HIV vaccine‑induced seropositivity in a South African research setting

BACKGROUND

The high HIV prevalence and incidence in South Africa makes it suitable for recruitment of participants for large-scale HIV preventive vaccine trials. However, fear of vaccine-induced seropositivity (VISP) may be a barrier for community acceptability of the trial, for volunteers to participate in HIV preventive vaccine trials and for uptake of an efficacious vaccine. Prior to 2015, when the first phase 1 safety HIV vaccine trial was undertaken at Setshaba Research Centre, Soshanguve, the local community stakeholders and healthcare workers were naive about HIV vaccine research and HIV preventive vaccines.

OBJECTIVE

To explore knowledge and perceptions regarding VISP among community stakeholders and healthcare workers in peri-urbanb Soshanguve, Tshwane.

METHODS

Using a quantitative-qualitative mixed-methods study design, surveys (n=50) and in-depth interviews (n=18) were conducted during July - August 2015. Participants included community stakeholders, community advisory board members and healthcare workers, who were >18 years old and had attended community educational workshops during September 2014 - May 2015. Audio recordings of interviews were transcribed verbatim and coded using content thematic analysis. Data were further analysed by sex, age and educational level.

RESULTS

Of a maximum score of 2 on knowledge on VISP, the 50 survey participants (mean age 33.78 years; 45 females) obtained an average of 0.88 (44%). Of 17 in-depth interviewees (one interview could not be transcribed; mean age 30.9 years; 12 females), 8 (47%) displayed some knowledge about VISP, of whom only 5 defined VISP correctly. Women were more knowledgeable about VISP than men; 5 of 12 women (42%) came close to defining VISP correctly, while none of the 5 men did so. The main fear of trial participation expressed by most participants (n=6) was testing HIV-positive as a result of the vaccine. While some participants believed that the community's perceptions of VISP would negatively affect HIV vaccine trial support and recruitment efforts, others noted that if trial participants understand the concept of VISP and are part of support groups, then they would have the information to combat negative attitudes within their community.

CONCLUSION

Most participants had an inaccurate and incomplete understanding of VISP. Many feared testing HIV-positive at clinics; therefore, education on improving a basic understanding of how vaccines work and why VISP occurs is essential. In addition, assessing participant understanding of HIV testing, transmission and VISP is critical for recruitment of participants into HIV vaccine trials and may improve acceptability of an HIV preventive vaccine.

A randomized trial to assess retention rates using mobile phone reminders versus physical contact tracing in a potential HIV vaccine efficacy population of fishing communities around Lake Victoria, Uganda

Background

High retention (follow-up) rates improve the validity and statistical power of outcomes in longitudinal studies and the effectiveness of programs with prolonged administration of interventions. We assessed participant retention in a potential HIV vaccine trials population of fishing communities along Lake Victoria, Uganda.

Methods

In a community-based individual randomized trial, 662 participants aged 15–49 years were randomized to either mobile phone or physical contact tracing reminders and followed up at months 1, 2, 3, 6, 12 and 18 post-enrolment. The visit schedules aimed at mimicking a vaccine efficacy trial representing an early interval (months 1–6) where most vaccinations would be administered and a later period of post-vaccination follow-up. The primary outcome was retention measured as the proportion of post-baseline follow up visits completed by a participant. Retention was estimated in early and later follow-up intervals, and overall for all the six follow-up visits. Adjusted differences in retention between the study arms were determined by multivariable logistic regression using Stata® 14. One participant was later dropped from the analysis because of age ineligibility discovered after enrolment.

Results

Of the expected total follow up visits of 3966 among 661 participants, 84.1% (3334) were attained; 82.1% (1626/1980) in the phone arm and 86% (1708/1986) in the physical tracing arm (p = 0.001). No statistically significant differences in retention were observed between the study arms in the first 6 months but thereafter, retention was significantly higher for physical contact reminders than mobile phones; 91.5% versus 82.1% (p < 0.0001) at month 12 and 82.8% versus 75.4%, (p = 0.021) at month 18. Controlling for sex, age, education, occupation, community location, length of stay and marital status, the odds of good retention (completing 5 out of 6 follow-up visits) were 1.56 (95% CI;1.08–2.26, p = 0.018) for physical contact tracing compared to mobile phone tracing. Other statistically significant predictors of good retention were residing on islands and having stayed in the fishing communities for 5 or more years.

Conclusions

Among fishing communities of Lake Victoria, Uganda, 84% of follow-up visits can be attained and participant retention is higher using physical contact reminders than mobile phones.

Trial registration number

PACTR201311000696101 (http://www.pactr.org/). retrospectively registered on 05 November, 2013.

Using surrogate vaccines to assess feasibility and acceptability of future HIV vaccine trials in men: a randomised trial in inner-city Johannesburg, South Africa

BACKGROUND

Developing an effective HIV vaccine is the overriding priority for HIV prevention research. Enrolling and maintaining cohorts of men into HIV vaccine efficacy trials is a necessary prerequisite for the development and licensure of a safe and efficacious vaccine.

METHODS

One hundred-fifty consenting HIV-negative men were enrolled into a pilot 1:1 randomised controlled trial of immediate vaccination with a three-dose hepatitis B vaccine compared to deferred vaccination (at 12 months) to investigate feasibility and acceptability of a future HIV vaccine trial in this population. Adverse events, changes in risk behaviour, acceptability of trial procedures and motivations for participation in future trials were assessed.

RESULTS

Men were a median 25 years old (inter-quartile range = 23-29), 53% were employed, 90% secondary school educated and 67% uncircumcised. Of the 900 scheduled study visits, 90% were completed in the immediate vaccination arm (405/450) and 88% (396/450) in the delayed arm (P = 0.338). Acceptability of trial procedures and services was very high overall. However, only 65% of the deferred group strongly liked being randomised compared to 90% in the immediate group (P = 0.001). Informed consent processes were viewed favourably by 92% of the delayed and 82% of the immediate group (P = 0.080). Good quality health services, especially if provided by a male nurse, were rated highly. Even though almost all participants had some concern about the safety of a future HIV vaccine (98%), the majority were willing to participate in a future trial. Future trial participation would be motivated mainly by the potential for accessing an effective vaccine (81%) and altruism (75%), rather than by reimbursement incentives (2%).

CONCLUSIONS

Recruitment and retention of men into vaccine trials is feasible and acceptable in our setting. Findings from this surrogate vaccine trial show a high willingness to participate in future HIV vaccine trials. While access to potentially effective vaccines is important, quality health services are an equally compelling incentive for enrolment.