"It Depends How One Understands It:" A Qualitative Study on Differential Uptake of Oral Cholera Vaccine in Three Compounds in Lusaka, Zambia

"2017 marked the 200th anniversary of the first pandemic wave of cholera....Much like the bacteria that has paradoxically thrived in modern times, vaccine hesitancy and skepticism of the science behind vaccines has risen in the age of information..."

Studies have shown that participation in oral cholera vaccine (OCV) campaigns can be impacted by perceptions of cholera, past experience with vaccinations, social disenfranchisement/marginalisation, fear of vaccine side effects, and opportunity costs. In the context of the cholera outbreak from February to May 2016 in Lusaka, Zambia, this study compares the perspectives of those who self-reported (i) not receiving the vaccine and (ii) receiving both OCV doses in Chawama, Kanyama, and Bauleni compounds (overcrowded informal settlements) to understand factors that could impact this population's participation in future campaigns in Zambia. The goal is to add to "the limited literature on contextualized assessments to anticipate and better understand vaccine uptake challenges undertaken in Africa for OCV and oral vaccines in general."

This analysis is nested in a larger rapid qualitative assessment conducted before, during, and after the second-dose OCV campaign carried out in December 2016 (see Related Summaries, below). In the current analysis, the researchers compare responses from 18 focus group discussions (FGDs) conducted in the 3 compounds, including 6 each with men and women who reported being unvaccinated at the first (April 2016) and second (December 2016) campaigns respectively and 6 with men and women who reported being fully vaccinated by the end of the second campaign. Each FGD had between 8 and 12 participants, for a total of 171 discussants, of whom 89 were female and 82 were male.

The presentation of results, which features illustrative quotes from FDG participants, follows the framework provided by the health belief model (HBM). The HBM holds that the adoption of prevention measures depends on whether people believe: that they are vulnerable to the disease (perceived susceptibility), that the disease comes with severe health or social consequences (perceived severity), and that the benefits of preventing the disease (perceived benefits) outweigh the barriers of adoption such as cost, time, pain, and side effects (perceived barriers). In addition, the researchers consider the influence of cultural beliefs regarding disease causation and social interactions on OCV uptake.

Most of those who were vaccinated heard about the campaign from community sources such as "people from health going around campaigning" and announcing it over a megaphone, community sensitisation in school and at church, home visits, and friends and family (including those working in health). Only one person mentioned radio and two cited television as sources of information. Most people opted for both OCV doses because they believed their sources when they said they should protect themselves, preserve their health, and preserve their lives through OCV.

All participants thought cholera to be severe and the reactive OCV campaign to be relevant if efficacious. Those who took both doses listed more risk factors (including "wind") and felt personally susceptible to cholera and protected by OCV. Participants from both the non-vaccinated and fully vaccinated groups declared that children and the economically poor were more vulnerable. In total, 60% of participants in each group had children, and 91% of those in the non-vaccinated group said they would not give their children OCV.

Cultural understanding of medicinal potency and perceived side effects adversely impacted OCV uptake. Those who did not take OCV felt protected by their good personal hygiene practices or thought of themselves and OCV as powerless against the multiple causes of cholera, including poor living conditions, water, wind, and curse. Most of those who did not take OCV feared side effects reported by others. Some interpreted side effects as "western" malevolence. ("A previous study suggests that distrust of health interventions in Zambia perhaps stems from a colonial history of usurpation expressed as concerns of exploitation and appropriation of bodies by people with power and/or knowledge..."). Although more than 80% of discussants reported not knowing duration of protection, some who did not vaccinate suggested that rather than rely on OCV, which could lose potency, collective action should be taken to change the physical and economic environment to prevent cholera.

Two unvaccinated participants reported that the volunteers at vaccination spots can be "harsh" and unwelcoming, and some indicated that more people would get vaccinated if OCV was part of routine care or available in their local clinic. Alternatively, OCV could be offered twice a month in the community, or campaign periods could be extended. In the community, door-to-door delivery was suggested to mitigate barriers posed by distance or being physically challenged. Participants thought sensitisation sessions should occur early in the morning before people leave for work.

Limited access to information during the campaign was another key factor. Most reported not receiving information on OCV side effects and duration of protection. This lack of information reportedly made the observed side effects all the more disturbing and granted credibility to those participants who warned about the vaccine's lack of safety, even if based on unfounded rumours. (Women in particular were identified as easily misdiagnosing side effects and of spreading rumours.) In fact, family and friends advising against OCV was reported by 63% of non-vaccinated and 26% of fully vaccinated participants as a reason why people may refuse OCV.

According to the researchers, the recommendation for clear, accurate, and targeted information given by some of the discussants appears sound. Discussants urged provision of information on who should be vaccinated, the period of protection, and side effects to counter the strong social influence on individual decision-making. "Hence, as suggested for other settings, transparency and clear information on vaccine safety and efficacy is needed to address vaccine hesitancy in Lusaka..." The presence of belief about wind-related causation of cholera also suggests the need for regular communication using consistent messaging on cholera sources, prevention, and treatment.

In conclusion: "In Lusaka compounds, vaccine hesitancy is a complex decision-making process rooted in circulating narratives, historical international interactions, and observable outcomes of vaccination....As the local explanatory model for both health and illness lies in the maintenance of social relationships, campaigns must emphasize collective uptake to achieve herd immunity as well as use social networks to provide accurate information on OCV."