Willingness to participate in COVID-19 vaccine trials; a survey among a population of healthcare workers in Uganda.

BACKGROUND: Healthcare workers (HCWs) are at high risk of acquiring SARS-CoV-2 and COVID-19 and may therefore be a suitable population for COVID-19 vaccine trials. We conducted a survey to evaluate willingness-to-participate in COVID-19 vaccine trials in a population of HCWs at three hospitals in Uganda. METHODS: The survey was conducted between September and November 2020. Using a standardised questionnaire, data were collected on socio-demographics, previous participation in health research, COVID-19 information sources, underlying health conditions, and willingness-to-participate in COVID-19 vaccine trials. Data were analysed descriptively and a binomial generalised linear model with a log link function used to investigate factors associated with unwillingness to participate. RESULTS: 657 HCWs (female, 63%) were enrolled with a mean age of 33 years (Standard Deviation, 10). Overall willingness-to-participate was 70.2%. Key motivating factors for participation were: hope of being protected against COVID-19 (81.1%), altruism (73.3%), and the opportunity to get health care (26.0%). Selected hypothetical trial attributes reduced willingness-to-participate as follows: weekly-quarterly study visits over a 12-month period (70.2%-63.2%, P = 0.026); provision of approximately 50ml of blood at each study visit (70.2%-63.2%, P = 0.026); risk of mild-moderate local adverse reactions (70.2%-60.3%, P<0.001); chance of receiving candidate vaccine or placebo (70.2%-56.9%, P<0.001); and delay of pregnancy [Overall, 70.2%-57.1% P<0.001); Female, 62.8%-48.4% (P = 0.002); Male, 82.5%-71.5% (P = 0.003)]. Collectively, these attributes reduced willingness-to-participate from [70.2%-42.2% (P<0.001) overall; 82.5%-58.1% (P<0.001) in men; 62.8%-32.6% (P<0.001) in women]. Among individuals that were unwilling to participate, the commonest barriers were concerns over vaccine safety (54.6%) and fear of catching SARS-CoV-2 (31.6%). Unwillingness to participate was associated with being female (aRR 1.97, CI 1.46-2.67, P<0.001) and having university or other higher-level education (aRR 1.52, CI 1.05-2.2, P = 0.026). CONCLUSIONS: Willingness-to-participate in COVID-19 vaccine trials among HCWs in Uganda is high but may be affected by vaccine trial requirements and concerns about the safety of candidate vaccines.

Feasibility of establishing an HIV vaccine preparedness cohort in a population of the Uganda Police Force: Lessons learnt from a prospective study.

BACKGROUND: Members of uniformed armed forces are considered to be at high risk for HIV infection and have been proposed as suitable candidates for participation in HIV intervention studies. We report on the feasibility of recruitment and follow up of individuals from the community of the Uganda Police Force (UPF) for an HIV vaccine preparedness study. METHODS: HIV-negative volunteers aged 18-49 years, were identified from UPF facilities situated in Kampala and Wakiso districts through community HIV counselling and testing. Potential volunteers were referred to the study clinic for screening, enrolment and quarterly visits for one year. HIV incidence, retention rates were estimated and expressed as cases per 100 person years of observation (PYO). Rate ratios were used to determine factors associated with retention using Poisson regression models. RESULTS: We screened 560 to enroll 500 volunteers between November 2015 and May 2016. One HIV seroconversion occurred among 431 PYO, for an incidence rate of 0.23/100 PYO (95% confidence interval [CI]: 0.03-1.64). Overall, retention rate was 87% at one year, and this was independently associated with residence duration (compared to <1 year, 1 to 5 years adjusted rate ratio (aRR) = 1.19, 95%CI: 1.00-1.44); and >5 years aRR = 1.34, 95%CI: 0.95-1.37); absence of genital discharge in the last 3 months (aRR = 1.97, 95% CI: 1.38-2.83, absence of genital ulcers (aRR = 1.90, 95%CI: 1.26-2.87, reporting of new sexual partner in the last month (aRR = 0.57, 95%CI: 0.45-0.71, being away from home for more than two nights (aRR = 1.27, 95%CI: 1.04-1.56, compared to those who had not travelled) and absence of knowledge on HIV prevention (aRR = 2.67, 95%CI: 1.62-4.39). CONCLUSIONS: While our study demonstrates the feasibility of recruiting and retaining individuals from the UPF for HIV research, we did observe lower than anticipated HIV incidence, perhaps because individuals at lower risk of HIV infection may have been the first to come forward to participate or participants followed HIV risk reduction measures. Our findings suggest lessons for recruitment of populations at high risk of HIV infection.

Retention of adults from fishing communities in an HIV vaccine preparedness study in Masaka, Uganda.

INTRODUCTION: People living in fishing communities around Lake Victoria may be suitable for enrolment in HIV prevention trials because of high HIV incidence. We assessed the ability to recruit and retain individuals from fishing communities into an HIV vaccine preparedness cohort study in Masaka, Uganda. METHODS: HIV high risk, sero-negative adults (18-49 years) were identified from four fishing villages bordering Lake Victoria through door-to-door HIV counselling and testing (HCT). Interested persons were referred for screening, enrolment, and quarterly follow-up visits at a study clinic located approximately 30-40 kilometres away. Repeat HCT, HIV risk assessment, and evaluation and treatment for sexually transmitted infections were provided. Rates of and factors associated with study dropout were assessed using Poisson regression models. RESULTS: A total of 940 participants were screened between January 2012 and February 2015, of whom 654 were considered for the analysis. Over a two-year follow-up period, 197 (30.1%) participants dropped out of the study over 778.9 person-years, a dropout rate of 25.3 / 100 person-years of observation. Dropout was associated with being female (aRR = 1.56, 95% confidence interval [CI] 1.12-2.18), being 18-24 years (aRR = 1.64; 95% CI 1.03-2.60) or being 25-34 years (aRR = 1.63; 95% CI 1.04-2.55) compared to being 35+ years; having no education (aRR = 2.02; 95% CI: 1.23-3.31); living in the community for less than one year (aRR = 2.22; 95% CI: 1.46-3.38), or 1-5 years (aRR = 1.68; 95% CI: 1.16-2.45), compared to more than five years. CONCLUSIONS: Our results suggest that individuals from fishing communities can be recruited and retained in longitudinal studies; however, intensified participant tracing may be necessary for women, younger volunteers, those who are less educated and new residents.