Poliovirus Outbreak in New York State, August 2022: Qualitative Assessment of Immediate Public Health Responses and Priorities for Improving Vaccine Coverage

"The very first thing to do is address and block the misinformation […] then it's about building good information and having trusted community partners that can spread that through word of mouth and through public meetings and sharing stories of survivors making these diseases real." - public health professional participating in the research



In July 2022, a confirmed case of paralytic polio in an unvaccinated young adult without a relevant travel history for poliovirus exposure was reported in New York State (NYS), United States (US). A public health emergency was declared in NY state on September 9 2022, and the US clinical and environmental poliovirus detections met the World Health Organization (WHO) definition of circulating vaccine-derived poliovirus type 2 (cVDPV2).  The aims of this qualitative study were to: (i) review immediate public health responses in NYS to assess the challenges in addressing gaps in vaccination coverage; (ii) inform a longer-term strategy to improving vaccination coverage in under-vaccinated communities, and (iii) collect data to support comparative evaluations of transnational poliovirus outbreaks.



The outbreak constitutes only the second identification of community transmission of poliovirus in the US since 1979, when the country was declared polio free. Routine use of oral polio vaccine (OPV) was replaced with an all-inactivated polio vaccine (IPV) immunisation schedule in 2000 to remove all risks of vaccine-associated paralytic polio. In this outbreak, it is likely that cVDPV2 emerged in NYS following viral shedding in proximity to unvaccinated or under-vaccinated close contacts, who in turn extended transmission of VDPV2 within a large collective of people who were unvaccinated and in an area where IPV vaccination coverage is lower than the required 80-85% threshold to protect population health.



At the time VDPV2 was isolated, coverage for 3 doses of IPV at 24 months of age in Rockland County was 60.3% compared with the 79% state average. Rockland County has the largest Jewish population per capita of any county in the US, and a number of neighbourhoods are exclusively Haredi Jewish (often termed "ultra-Orthodox"). Studies report that vaccine uptake among Haredi populations is influenced by a range of issues, including access and convenience challenges due to larger families, a preference for delayed acceptance (vs. broadscale refusal), and targeted activism and misinformation campaigns that intensified questions/doubts, especially in the context of COVID-19 vaccination. Following an unrelated vaccine derived poliovirus type 3 (VDPV3) incident in Israel in March 2022 (prior to the subsequent VDPV2 incident in Israel in April), public health (PH) officials sought to highlight the risk of spread from Israel to NYS due to lower-level vaccination coverage in New York's Haredi population.



For the study, 23 semi-structured interviews were conducted with PH professionals, healthcare professionals (HCPs), and community organisation (CO) partners. Results illustrate that a succession of PH challenges, locally and globally, combined with deficits in resources, meant that the county and federal PH officials involved in the polio outbreak response felt inadequately prepared to address low vaccination coverage in the affected areas. Diverse vaccine engagement and implementation activities were mobilised, but participants reported limitations in health systems.



Specific to communications and engagement, the cautious use of the internet among Haredi populations meant that print materials were considered crucial. Efforts to increase vaccination uptake and sanitation behaviour involved: an infographic in English, Yiddish, Spanish, and Creole; handwashing posters for children and adults; public letters in English and Yiddish addressed to residents; and a public letter signed by rabbinic authorities (in English and Hebrew). A key message of the infographic was the historical impact of immunisation in poliovirus prevention efforts. The infographic was endorsed by select healthcare providers and the local Hatzolah division (an Orthodox Jewish emergency medical technician [EMT] service), but one HCP viewed it as being information dense and unsuitable for quick synthesis of key messages in clinic waiting rooms.



Participants reported a need for investment in targeted vaccine engagement and suggested improvements in programme delivery and health systems strengthening to achieve sustainable gains in vaccination coverage. Their responses offer 3 priorities for strengthening vaccine programme activities:

• Maternal engagement - COs viewed women in Haredi communities as influential on decisions around paediatric vaccination, and hence important for vaccine engagement strategies. Women in Haredi communities may hold influential roles such as doulas, teachers, preschool leads, and wives of rabbinic authorities. Haredi women tend to consult rabbinic authorities on a range of health-related issues and interventions. Engaging rabbis in vaccine delivery strategies was not considered to be detrimental, and a public letter signed by approximately 2 dozen rabbinic authorities in Rockland County was circulated to encourage parental engagement with the poliovirus response. HCPs suggested that rabbinic announcements may help to encourage parents who delay vaccines to come forward, but would have little influence over Haredi parents who refused vaccines.
• Communication to counter misinformation - Establishing strong information pathways into the Haredi community was considered crucial to counter misinformation that has actively targeted Haredi neighbourhoods. HCPs requested guidance on how to communicate poliovirus transmission risk to parents and agreed this information should be presented as coming from providers rather than PH agencies. "A vaccine engagement strategy produced by a collaboration between public health staff, healthcare professionals, and community partners is required to counter non-vaccination advocacy and address concerns with credible information. The input of community organisations and partners, which includes mothers and parents, is crucial to ensure the content and delivery channels are acceptable to Haredi families....Yet, vaccine engagement requires a commitment to consistently channel information about childhood vaccinations as part of a broader approach to family health messaging, not just in an outbreak."
• Vaccine policy and data management - Issues of delay, which affect the Haredi population, require different solutions and communications compared to vaccine refusal. Tailored vaccine engagement strategies may help to convey the role that the childhood vaccination schedule plays in preventing vaccine-preventable diseases (VPDs) and illness, not just as a requirement for school entry. Moreover, the idea that vaccines are solely required for school entry leaves an entire population of children less than 24 months vulnerable to infection. Assessing vulnerable children who remained unvaccinated or under-vaccinated may have been complicated by imperfections in health information systems. Enhancing the ability to track gaps and changes in coverage will support accurate evaluations of outbreak responses and vaccine engagement strategies.

Among the specific suggestions for vaccine engagement going forward: Collaboratively produced health updates can be directly and regularly channelled to Haredi mothers (the principal decision-makers on child health) in print or through short, recorded phone messages. Such updates can be disseminated via primary care providers because healthcare providers are regarded as trusted sources of information, possibly more so than PH agencies (see figure above). Appropriate community branding may help to make the health updates appear relevant to local context. Collaboration with community agencies on communication (or vaccine delivery) may be fruitful. In ensuring smooth functioning and sustainability of PH relationships with COs and partners as part of vaccination engagement programmes, the division of responsibilities should be explicit, and pursuit of goals should be shared.



Future research could explore the entire timeline of the response to better understand household expectations of vaccine communication strategies and their perceptions of accessible services how effective longer-term vaccine engagement strategies might be. Lessons learned from countries who have responded to polio outbreaks in networked communities might help develop transnational solutions to shared challenges.



Thus, this polio outbreak in the US underscores the importance of community-specific, regional, as well as country-wide responsive vaccination programmes that depend on a significant mobilisation of PH resources. Priorities for improving and maintaining higher coverage levels include developing vaccine engagement strategies with populations that remain vulnerable to illness from VPDs and enabling efficient data management and sharing for learning at regional and international levels.