Factors Influencing Participation in an Ebola Vaccine Trial among Front-Line Workers in Guinea

"...deep-seated mistrust of international organizations, government agencies, and medical professionals...hampered response efforts and indubitably impacted recruitment in this vaccine trial."

A Phase III trial in Guinea and Sierra Leone to assess the efficacy of Merck's recombinant, replication-competent vesicular stomatitis virus (rVSV) vaccine began in March 2015. As part of a sub-study of the 'Ebola ça suffit' trial, a qualitative study was conducted to explore motivations behind individuals' decisions to participate - or not to participate - in the trial, with the associated goals of improving engagement as the trial progressed and informing future trials or use of the vaccine. This paper presents the results of the qualitative study and discusses the social, political, and ethological factors highlighted by participants and lessons learned for future trials.

In Conakry, Guinea, interviews and focus groups were carried out in July and August 2015 among 110 persons, of whom 67% participated in the vaccine trial. They included front-line workers (FLWs) and members of the vaccine trial team, such as health promoters, referring doctors, and investigators. Themes of participation and non-participation included:

1. Protection in a high-risk setting: Protecting oneself and one's family was the most commonly provided argument in favor of participating, particularly among young women with children and older women. FLWs explained that protecting themselves would allow them to continue providing urgently needed medical care.
2. Costs and benefits of participation: Most non-participants referenced the experimental nature and perceived "risk" of the vaccine when explaining their refusal to participate. Other "costs" were cited, with some simply saying, "time is money", while others questioning why they weren't given a cash payment, "the way they do for whites in the west". By far the greatest perceived benefit to participation, as discussed above, was the opportunity for participants to protect themselves from Ebola virus disease (EVD).
3. Desire to set an example: Several healthcare workers indicated that their participation was driven by a desire to be consistent with their own advice to patients and to lead by example. Individuals in supervisory roles also expressed the idea that their participation in the trial might influence their employees to participate.
4. Distrust and contempt towards international organisations: The nature of the epidemic gave rise to many conspiracy theories, including that Ebola had been introduced by whites in order to eradicate the population, or that the epidemic was a ploy by the pharmaceutical companies with profit motives. Some were even suspicious that blood was being collected for reasons other than determining vaccine performance, such as screening Ebola patients for quarantine. Suspicion of the vaccine trial organisers was heightened by the fact that staff members did not participate in the trial.
5. Stigmatisation of trial participants: Interviewees expressed fear of being exiled should there be undesirable effects of vaccination, especially if the side effects resemble EVD symptoms. Participants worried they would chastised for colluding with foreigners and other suspicious entities, for endangering their colleagues and family if they are forced to stop working, and for selling or degrading their body by accepting compensation to be vaccinated and have blood drawn.
6. Motivation to aid in development of a vaccine: Nurses, doctors, and department heads were mostly likely to frame their choice to participate as a matter of scientific progress.

In light of these findings, the researchers stress that special consideration should be given to addressing perceived inequity, misunderstanding, and mistrust among the intended populations in future trials. Distrust or skepticism of the medical community and Western organisations is amplified in countries like Guinea with a history of conflict, racism, oppression, and colonial research. For example, fears of blood theft, misuse of blood, or over-collection are widespread in sub-Saharan Africa and need to be considered during trial planning and implementation, the researchers stress. They recommend that efforts be made to identify and understand the provenance of any misunderstandings, including historical and social factors, and to address these in a transparent and directed fashion. Providing consistent and clear information throughout recruitment and the entire process, they stress, is critical to improving participation and community engagement as well as ensuring consent is fully informed.

Furthermore: "The spread of misinformation and hysteria, driven largely by sensationalist and inaccurate media reports and hearsay, may have negatively influenced people's understanding and opinion of the outbreak and vaccine trials, and are an important factor to consider in future outbreaks of this scope."

In conclusion: "The staff of this study found that collaborative meetings, in which there was equitable discussion among and between potential participants, were more effective in recruiting subjects in healthcare settings than meetings structured as a classroom presentation, without discussion between FLWs. If instituted in the community as well, these roundtable discussions may help establish a sense of communitarianism and general goodwill towards the trial and in turn eliminate the spread of misinformation and risk of stigmatization."