Ebola Vaccine Uptake and Attitudes among Healthcare Workers in North Kivu, Democratic Republic of the Congo, 2021

"Interventions aimed at increasing trust in the vaccine by disseminating accurate vaccine information and addressing rumors may aid in increasing Ebola vaccine uptake during future outbreaks."

There is evidence that vaccination attitudes among healthcare workers (HCWs) predict their vaccine uptake and intention to recommend vaccine in both routine health care settings and during health emergencies. During the 10th outreak (2018-2020) of Ebola virus disease (EVD) in the eastern part of the Democratic Republic of the Congo (DRC), prevention and control measures such as Ebola vaccination were challenging by community mistrust. Understanding attitudes among HCWs is not only important because they are at high risk for EVD infection, but also because HCWs can play an important role in encouraging others in the community to be vaccinated. Thus, this study aimed to understand perceptions regarding Ebola vaccination and identify determinants of Ebola vaccine uptake among HCWs.

In March 2021, the researchers conducted a cross-sectional survey among 438 HCWs from 100 health facilities in 3 health zones (Butembo, Beni, Mabalako) that had high EVD case counts and reports of community resistance to response activities during the 10th outbreak in DRC. The researchers used survey logistic regression to assess correlates of first-offer uptake (i.e., having received the vaccine the first time it was offered vs. after subsequent offers). A structured questionnaire focused on 5 areas that were expected to influence vaccine uptake: perceived risk, communications (including rumors, misinformation, community engagement), societal factors (including religion, community leaders, government, security concerns), health systems (e.g., vaccination teams, geography, logistics), and vaccine-specific factors (e.g., safety and efficacy).

Of the 438 HCWs enrolled in the study, 420 (95.8%) reported they were eligible and offered an Ebola vaccine. Among those offered vaccination, self-reported uptake of the Ebola vaccine was 99.0% (95% confidence interval (CI) [98.5-99.4]), but first-offer uptake was 70.2% (95% CI [67.1, 73.5]). Thus, while the majority of HCWs considered EVD to be a serious disease that could kill them, almost a third of the eligible HCWs delayed vaccination. Nearly half (48.3%; [95% CI: 45.7-51]) of the vaccinated participants (n = 416) reported they had concerns about the vaccine when they received it. The most common concerns were that the vaccine would cause side effects (65.7%; [95% CI: 61.4-69.7]), death (48.5%; [95% CI:44.6-52]), EVD (29.4%; [95% CI: 26.4-32.5%]), or infertility (33.3%; [95% CI: 29.3-37.4]).

 

Futhermore, 5.7% (95% CI: [4.7-7.0]) of the overall sample of HCWs strongly agreed and 21.0% (95% CI: 18.9%-23.3%) agreeing they did not trust the Ebola vaccine source or how it was produced. In the multivariable analysis, participants who expressed mistrust of the vaccine source or how the vaccine was produced were found to have lower odds of first-offer vaccine uptake (adjusted odds ratio (aOR) 0.38 [95% CI: 0.30-0.47]). Being a response worker, the perception that Ebola could be prevented with a vaccine, and having higher general confidence in vaccines were also associated with higher odds of accepting the vaccine on first offer.

Among all respondents, 64.6% (95% CI: [61.4-67.7]) felt that the Ebola vaccine should be mandatory for HCWs.

Participants had overall positive attitudes toward vaccines in general, with 88.6% (95% CI: [86.8-90.2]) reporting they "very much" or "somewhat" agreed that vaccines are good, and 81.7% (95% CI: [79.5-83.8]) "very much" or "somewhat" agreed that vaccines are safe. However, only 10.3% (95% [CI: 8.5-12.3]) reported that the community spoke positively about vaccines in general, while 24.9% (95% [CI: 22.5-27.5]) reported the community spoke negatively.

Thus, despite a high level of vaccine acceptance in this HCW population, mixed perceptions regarding the vaccine were common, and about 10% only accepted after 4 or more offers. These findings underscore the importance of efforts to engage the "moveable middle" - i.e., the group who has vaccine concerns but who is open to changing vaccination intent with additional information. With any new vaccine introduction, clear communication on potential vaccine side effects and its safety and efficacy is crucial.

Circulating rumours and misinformation on social media and throughout the local community may have contributed to the concerns, including that the experimental drugs and vaccines were brought to exterminate the local population, that the vaccine might cause death or EVD, and/or that it could lead to infertility or sexual dysfunction. It is also important to note that this EVD outbreak occurred in an active conflict zone, where low institutional trust has been documented. In 2019, community resistance, including attacks on response teams, HCWs, and Ebola treatment centres, escalated as armed group activities also increased. The EVD response work was frequently undermined by misinformation from government authorities, and the rapid mobilisation of staff and resources for the EVD outbreak contradicted the government's failure to protect the community from continuous violence. Prior work from the region suggested that low levels of trust in government institutions and dissatisfaction with perceived inadequacies in the response effort, including violation of cultural burial practices, have been linked to reducing adherence to EVD preventive behaviours.

As the researchers note, HCWs are prioritised for the Ebola vaccination owing to their nature of work; therefore, addressing vaccine confidence issues in HCWs early on can also contribute to better peer-to-peer support for improving social norms around vaccination. HCWs also act as ambassadors for trusted health information and vaccine confidence in the local community. Thus, the development of targeted strategies that empower HCWs with knowledge and ways to combat misinformation may lead to improved community uptake of the vaccine.

Taken together, the findings highlight the need to address underlying trust in the vaccine and the fact that uptake is enhanced with multiple vaccination offers. Vaccine outreach activities with strong risk communication and community engagement efforts that improve the timeliness of EVD vaccination among HCWs may have the dual benefit of protecting the frontline workforce and increasing the likelihood that HCWs may encourage others to take the vaccine. Early efforts to target this group can build vaccine confidence, which is important in controlling outbreaks of vaccine preventable diseases. Regularly using social data from the Integrated Outbreak Analytics (IOA) approach and other behavioural surveys can provide actional evidence to improve response activities. "Future Ebola vaccination efforts should plan to make repeated vaccination offers to HCWs and address their underlying mistrust in the vaccines, which can, in turn, improve community uptake."

Full list of authors, with institutional affiliations: Reena H. Doshi, Centers for Disease Control and Prevention (CDC); Stephanie C. Garbern, Brown University; Shibani Kulkarni, CDC; Shiromi M. Perera, International Medical Corps; Monica K. Fleming, CDC; Rigobert Fraterne Muhayangabo, International Medical Corps; Arsene Balene Ombeni, International Medical Corps; Dieula Delissaint Tchoualeu, CDC; Ruth Kallay, CDC; Elizabeth Song, Brown University; Jasmine Powell, Brown University; Monique Gainey, Rhode Island Hospital; Bailey Glenn, James A. Ferguson Infectious Disease Program; Ruffin Mitume Mutumwa, International Medical Corps; Stephane Hans Bateyi Mustafa, Expanded Programme on Immunization, Goma, Democratic Republic of Congo; Giulia Earle-Richardson, CDC; Hongjiang Gao, CDC; Neetu Abad, CDC; Gnakub Norbert Soke, CDC; David L. Fitter, CDC; Terri B. Hyde, CDC; Dimitri Prybylski, CDC; Adam C. Levine, International Medical Corps; Mohamed F. Jalloh, CDC; and Eta Ngole Mbong, International Medical Corps