2022 Polio outbreak, Rockland County, NY: Cost evaluation of strategies to prevent future outbreaks of vaccine-preventable diseases.

In 1994, the World Health Organization Region of the Americas was declared polio-free. In July 2022, a confirmed case of paralytic polio in an unvaccinated adult resident of Rockland County, New York was reported by the New York State Department of Health (NYSDOH) and Rockland County Department of Health (RCDOH). While only one case was identified, a single case of paralytic polio represents a public health emergency in the United States. The patient's county of residence was identified to have low vaccination coverage indicating that the community was at risk for additional cases. Disease outbreaks are resource-intensive and incur high costs to the patient, local health departments, and to society. These costs are potentially avoidable for vaccine-preventable diseases and thus, highlight the urgency to not only interrupt transmission but to prevent future vaccine-preventable disease outbreaks by improving vaccination coverage. Following case confirmation, an investigation and response was initiated by NYSDOH, along with local health departments and the Centers for Disease Control and Prevention (CDC). After the initial investigation and response, collaborative efforts to mitigate risk and strengthen routine immunization continued, which included provider outreach and immunization record assessments of Head Start and licensed childcare facilities (primarily those with missing or incomplete required vaccination coverage reports from the previous year) in Rockland County. We estimated the costs of (1) provider outreach and (2) childcare and pre-kindergarten immunization record assessments of select licensed childcare and Head Start facilities in Rockland County. The total labor cost incurred for these activities was $138,514 with a total of 2,555 h incurred. Often there are unique opportunities in the midst of an outbreak for public health to implement activities to proactively address low vaccination and strengthen vaccination coverage and possibly prevent future outbreaks. Understanding the cost of these activities might help inform future outbreak planning.

Health Economic Analysis of Antiviral Drugs in the Global Polio Eradication Endgame.

BACKGROUND: Polio antiviral drugs (PAVDs) may provide a critical tool in the eradication endgame by stopping poliovirus infections in immunodeficient individuals who may not clear the virus without therapeutic intervention. Although prolonged/chronic poliovirus excreters are rare, they represent a source of poliovirus reintroduction into the general population. Prior studies that assumed the successful cessation of all oral poliovirus vaccine (OPV) use estimated the potential upper bound of the incremental net benefits (INBs) of resource investments in research and development of PAVDs. However, delays in polio eradication, OPV cessation, and the development of PAVDs necessitate an updated economic analysis to reevaluate the costs and benefits of further investments in PAVDs. METHODS: Using a global integrated model of polio transmission, immunity, vaccine dynamics, risks, and economics, we explore the risks of reintroduction of polio transmission due to immunodeficiency-related vaccine-derived poliovirus (iVDPV) excreters and reevaluate the upper bound of the INBs of PAVDs. RESULTS: Under the current conditions, for which the use of OPV will likely continue for the foreseeable future, even with successful eradication of type 1 wild poliovirus by the end of 2023 and continued use of Sabin OPV for outbreak response, we estimate an upper bound INB of 60 million US$2019. With >100 million US$2019 already invested in PAVD development and with the introduction of novel OPVs that are less likely to revert to neurovirulence, our analysis suggests the expected INBs of PAVDs would not offset their costs. CONCLUSIONS: While PAVDs could play an important role in the polio endgame, their expected economic benefits drop with ongoing OPV use and poliovirus transmissions. However, stakeholders may pursue the development of PAVDs as a desired product regardless of their economic benefits.HighlightsWhile polio antiviral drugs could play an important role in the polio endgame, their expected economic benefits continue to drop with delays in polio eradication and the continued use of oral poliovirus vaccines.The incremental net benefits of investments in polio antiviral drug development and screening for immunodeficiency-related circulating polioviruses are small.Limited global resources are better spent on increasing global population immunity to polioviruses to stop and prevent poliovirus transmission.

Poliovirus outbreak in New York State, August 2022: qualitative assessment of immediate public health responses and priorities for improving vaccine coverage.

In 2022, a case of paralysis was reported in an unvaccinated adult in Rockland County (RC), New York. Genetically linked detections of vaccine-derived poliovirus type 2 (VDPV2) were reported in multiple New York counties, England, Israel, and Canada. The aims of this qualitative study were to: i) review immediate public health responses in New York 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. Twenty-three semi-structured interviews were conducted with public health professionals, healthcare professionals, and community partners. Results indicate that i) addressing suboptimal vaccination coverage in RC remains a significant challenge after recent disease outbreaks; ii) the poliovirus outbreak was not unexpected and effort should be invested to engage mothers, the key decision-makers on childhood vaccination; iii) healthcare providers (especially paediatricians) received technical support during the outbreak, and may require resources and guidance to effectively contribute to longer-term vaccine engagement strategies; vi) data systems strengthening is required to help track under-vaccinated children. Public health departments should prioritize long-term investments in appropriate communication strategies, countering misinformation, and promoting the importance of the routine immunization schedule.

Responding to Africa's burden of disease: accelerating progress.

Although Africa is home to about 14% of the global population (1.14 billion people), it is growing three times faster than the global average [1]. The continent carries a high burden of disease, but there has been real progress in eradication, elimination, and control since 2015. Examples are the eradication of wild polio in 2020 [2] and the eradication or elimination of neglected tropical diseases, such as dracunculiasis in Kenya in 2018; Human African trypanosomiasis in Togo in 2022; and trachoma in Togo, Gambia, Ghana, and Malawi in 2022 [3]. New HIV infections reduced by 44% in 2021 compared to 2010 [4], and in 2021 the African region passed the 2020 milestone of the End TB Strategy, with a 22% reduction in new infections compared with 2015 [5].

Immunity to poliovirus in Afghanistan: A household sampling method for serological assessment based on geographical information systems.

Afghanistan continues to experience challenges affecting polio eradication. Mass polio vaccination campaigns, which aim to protect children under the age of 5, are a key eradication strategy. To date, the polio program in Afghanistan has only employed facility-based seroprevalence surveys, which can be subject to sampling bias. We describe the feasibility in implementing a cross-sectional household poliovirus seroprevalence survey based on geographical information systems (GIS) in three districts. Digital maps with randomly selected predetermined starting points were provided to teams, with a total target of 1,632 households. Teams were instructed to navigate to predetermined starting points and enrol the closest household within 60 m. To assess effectiveness of these methods, we calculated percentages for total households enrolled with valid geocoordinates collected within the designated boundary, and whether the Euclidean distance of households were within 60 m of a predetermined starting point. A normalized difference vegetation index (NDVI) image ratio was conducted to further investigate variability in team performances. The study enrolled a total of 78% of the target sample with 52% of all households within 60 m of a pre-selected point and 79% within the designated cluster boundary. Success varied considerably between the four target areas ranging from 42% enrolment of the target sample in one place to 90% enrolment of the target sample in another. Interviews with the field teams revealed that differences in security status and amount of non-residential land cover were key barriers to higher enrolment rates. Our findings indicate household poliovirus seroprevalence surveys using GIS-based sampling can be effectively implemented in polio endemic countries to capture representative samples. We also proposed ways to achieve higher success rates if these methods are to be used in the future, particularly in areas with concerns of insecurity or spatially dispersed residential units.

Assessment of serological responses following vaccination campaigns with type 2 novel oral polio vaccine: a population-based study in Tajikistan in 2021.

BACKGROUND: Novel oral poliovirus vaccine type 2 (nOPV2) was used to control an outbreak of type 2 circulating vaccine derived poliovirus (cVDPV2) in Tajikistan, in 2021. We measured seroconversion and seroprevalence of type 2 polio antibodies in children who were reported to have received two doses of nOPV2 in outbreak response campaigns. METHODS: In this community serosurvey, children born after Jan 1, 2016 were enrolled from seven districts in Tajikistan. Dried blood spot cards were collected before nOPV2 campaigns and after the first and second rounds of the campaigns and were sent to the Centers for Disease Control and Prevention (Atlanta, GA, USA) for microneutralisation assay to determine presence of polio antibodies. The primary endpoint was to assess change in seroprevalence and seroconversion against poliovirus serotype 2 after one and two doses of nOPV2. FINDINGS: 228 (97%) of 236 enrolled children were included in the analysis. The type 2 antibody seroprevalence was 26% (53/204; 95% CI 20 to 33) before nOPV2, 77% (161/210; 70 to 82) after one dose of nOPV2, and 83% (174/209; 77 to 88) after two doses of nOPV2. The increase in seroprevalence was statistically significant between baseline and after one nOPV2 dose (51 percentage points [42 to 59], p<0·0001), but not between the first and second doses (6 percentage points [-2 to 15], p=0·12). Seroconversion from the first nOPV2 dose, 67% (89/132; 59 to 75), was significantly greater than that from the second nOPV2 dose, 44% (20/45; 30 to 60; χ2 p=0·010). Total seroconversion after two nOPV2 doses was 77% (101/132; 68 to 83). INTERPRETATION: Our study demonstrated strong immune responses following nOPV2 outbreak response campaigns in Tajikistan. Our results support previous clinical trial data on the generation of poliovirus type 2 immunity by nOPV2 and provide evidence that nOPV2 can be appropriate for the cVDPV2 outbreak response. The licensure and WHO prequalification of nOPV2 should be accelerated to facilitate wider use of the vaccine. FUNDING: World Health Organization, Centers for Disease Control and Prevention, and Rotary International.

Health economic analysis of vaccine options for the polio eradication endgame: 2022-2036.

BACKGROUND: Multiple vaccine options are available for polio prevention and risk management. Integrated global risk, economic, and poliovirus transmission modeling provides a tool to explore the dynamics of ending all use of one or more poliovirus vaccines to simplify the polio eradication endgame. RESEARCH DESIGN AND METHODS: With global reported cases of poliomyelitis trending higher since 2016, we apply an integrated global model to simulate prospective vaccine policies and strategies for OPV-using countries starting with initial conditions that correspond to the epidemiological poliovirus transmission situation at the beginning of 2022. RESULTS: Abruptly ending all OPV use in 2023 and relying only on IPV to prevent paralysis with current routine immunization coverage would lead to expected reestablished endemic transmission of poliovirus types 1 and 2, and approximately 150,000 expected cases of poliomyelitis per year. Alternatively, if OPV-using countries restart trivalent OPV (tOPV) use for all immunization activities and end IPV use, the model shows the lowest anticipated annual polio cases and lowest costs. CONCLUSIONS: Poor global risk management and coordination of OPV cessation remain a critical failure mode for the polio endgame, and national and global decision makers face difficult choices due to multiple available polio vaccine options and immunization strategies.

A novel semi-quantitative methodology for national poliovirus reintroduction and outbreak risk assessment.

BACKGROUND: Under the International Health Regulations (2005), World Health Organization Member States need to verify certification of polio-free status annually. In 2018, Australia sought to reassess and comprehensively characterise the risk posed by wild-type and vaccine-derived poliovirus introductions to national health security. However formal guidelines for national polio risk assessment were not publicly available. METHODS: Four risk elements were identified and weighted using an expert-informed modified Delphi method: reintroduction hazard; population susceptibility; detection capability; and response capability. Australian data and qualitative evidence were analysed, documented and scored against risk element indicators to characterise polio risk as a semi-quantitative estimate and qualitative risk category statement. RESULTS: The semi-quantitative risk characterisation calculated likelihood and impact scores of 0.43 and 0.13, respectively (possible range: 0.02-4.5). The assessment concluded that the risk of poliovirus reintroduction, resultant outbreaks of poliovirus infection, and sustained transmission occurring in Australia is very low. CONCLUSIONS: Until poliovirus is eradicated, it remains in countries' strategic health security interest to maintain optimal investment in polio prevention, preparedness, surveillance and response capability to manage their level of risk. We present a structured, transparent and reproducible methodology for national or sub-national polio risk characterisation that generates evidence for targeted investment to maintain polio-free status.

Assessing community engagement in Nigeria polio eradication initiative: application of the Consolidated Framework for Implementation Research.

OBJECTIVE: This study employed the Consolidated Framework for Implementation Research (CFIR) to assess factors that enhanced or impeded the implementation of community engagement strategies using the Nigerian polio programme as a point of reference. DESIGN: This study was a part of a larger descriptive cross-sectional survey. The CFIR was used to design the instrument which was administered through face-to-face and phone interviews as well as a web-based data collection platform, Qualtrics. SETTING: The study took place in at least one State from each of the six geopolitical zones in Nigeria (Nasarawa, Borno, Kano, Sokoto, Anambra, Bayelsa, Lagos, Ondo and Oyo States as well as the Federal Capital Territory). PARTICIPANTS: The respondents included programme managers, policy-makers, researchers and frontline field implementers affiliated with the Global Polio Eradication Initiative (PEI) core partner organisations, the three tiers of the government health parastatals (local, state and federal levels) and academic/research institutions. RESULTS: Data for this study were obtained from 364 respondents who reported participation in community engagement activities in Nigeria's PEI. Majority (68.4%) had less than 10 years' experience in PEI, 57.4% were involved at the local government level and 46.9% were team supervisors. Almost half (45.0%) of the participants identified the process of conducting the PEI program and social environment (56.0%) as the most important internal and external contributor to implementing community engagement activities in the community, respectively. The economic environment (35.7%) was the most frequently reported challenge among the external challenges to implementing community engagement activities. CONCLUSION: Community engagement strategies were largely affected by the factors relating to the process of conducting the polio programme, the economic environment and the social context. Therefore, community engagement implementers should focus on these key areas and channel resources to reduce obstacles to achieve community engagement goals.

Vaccine preventable diseases surveillance in Nepal: How much does it cost?

Assessing the cost of vaccine preventable diseases (VPD) surveillance is becoming more important in the context of the Global Polio Eradication Initiative (GPEI) funding transition, since GPEI support to polio surveillance helped the incremental building of VPD surveillance systems in many countries, including low income countries such as Nepal. However, there is limited knowledge on the cost of conducting VPD surveillance, especially the national cost for surveillance of multiple vaccine-preventable diseases. The current study sought to calculate the economic and financial costs of Nepal's comprehensive VPD surveillance systems from July 2016 to July 2017. At thecentral level, all surveillance units were included in the sample. At sub-national level, a purposive sampling strategy was used to select a representative sample from locations involved in conducting surveillance. The sub-national sample costs were extrapolated to the nationwide VPD surveillance system. Nepal's total annual economic cost of VPD surveillance was USD 4.81 million or USD 0.18 per capita, while the total financial cost was USD 4.38 million or USD 0.16 per capita. Government expenditures accounted for 56% of the total economic cost, and World Health Organization accounting for 44%. The biggest cost driver was personnel accounting for 51% of the total economic cost. WHO supported trained surveillance personnel through donor funding, mainly from Global Polio Eradication Initiative. As a polio transition priority country, Nepal will need to make strategic choices to fully self-finance or seek full donor support or a mixed-financing model as polio program funding diminishes.

Demographic and health surveys showed widening trends in polio immunisation inequalities in Guinea.

AIM: This study examined trends in absolute and relative socio-economic, gender and geographical inequalities in the coverage of polio immunisation in Guinea, West Africa, from 1999 to 2016. METHODS: Data from the 1999, 2005 and 2012 Guinea Demographic and Health Survey and the 2016 Guinea Multiple Indicator Cluster Survey were analysed using the World Health Organization's health equity assessment toolkit. We disaggregated polio immunisation coverage using five equity stratifiers: household economic status, maternal educational level, place of residence, child's gender and region. The four summary measures used were the difference, ratio, population attributable risk and population attributable fraction. A 95% confidence interval (CI) was constructed around point estimates to measure statistical significance. RESULTS: A total of 4778 1-year-old children were included. Polio immunisation coverage in 1999, 2005, 2012 and 2016 were 43.4%, 50.7%, 51.2% and 38.6%, respectively. Socio-economic and geographical inequalities in polio immunisation favoured children with educated mothers who came from richer families living in urban areas. There were also differences in the eight regions over the 1999-2016 study period. CONCLUSION: Targeting children from disadvantaged subgroups must be prioritised to ensure equitable immunisation services that help to eradicate polio in Guinea.

An Updated Economic Analysis of the Global Polio Eradication Initiative.

Despite a strong global commitment, polio eradication efforts continue now more than 30 years after the 1988 World Health Assembly resolution that established the Global Polio Eradication Initiative (GPEI), and 20 years after the original target of the year 2000. Prior health economic analyses estimated incremental net benefits of the GPEI of 40-50 billion in 2008 U.S. dollars (US$2008, equivalent to 48-59 billion US$2019), assuming the achievement of polio eradication by 2012. Given the delays in achieving polio eradication and increased costs, we performed an updated economic analysis of the GPEI using an updated integrated global model, and considering the GPEI trajectory as of the beginning of 2020. Applying similar methods and assuming eradication achievement in 2023, we estimate incremental net benefits of the GPEI of 28 billion US$2019, which falls below the prior estimate. Delays in achieving polio eradication combined with the widescale introduction of relatively expensive inactivated poliovirus vaccine significantly increased the costs of the GPEI and make it less cost-effective, although the GPEI continues to yield expected incremental net benefits at the global level when considered over the time horizon of 1988-2029. The overall health and financial benefits of the GPEI will depend on whether and when the GPEI can achieve its goals, when eradication occurs, the valuation method applied, and the path dependence of the actions taken. Reduced expected incremental net benefits of the GPEI and the substantial economic impacts of the COVID-19 pandemic pose large financial risks for the GPEI.

Disease Surveillance Investments and Administration: Limits to Information Value in Pakistan Polio Eradication.

In Pakistan, annual poliovirus investment decisions drive quantities of supplemental immunization campaigns districts receive. In this article, we assess whether increased spending on poliovirus surveillance is associated with greater likelihood of correctly identifying districts at high risk of polio with assignment of an elevated "risk ranking." We reviewed programmatic documents from Pakistan for the period from 2012-2017, recording whether districts had been classified as "high risk" or "low risk" in each year. Through document review, we developed a decision tree to describe the ranking decisions. Then, integrating data from the World Health Organization and Global Polio Eradication Initiative, we constructed a Bayesian decision network reflecting investments in polio surveillance and immunization campaigns, surveillance metrics, disease incidence, immunization rates, and occurrence of polio cases. We test these factors for statistical association with the outcome of interest-a change in risk rank between the beginning and the end of the one-year time period. We simulate different spending scenarios and predict their impact on district risk ranking in future time periods. We find that per district spending increases are associated with increased identification of cases of acute flaccid paralysis (AFP). However, the low specificity of AFP investment and the largely invariant ranking of district risk means that even large increases in surveillance spending are unlikely to promote major changes in risk rankings at the current stage of the Pakistan polio eradication campaign.

Updated Characterization of Outbreak Response Strategies for 2019-2029: Impacts of Using a Novel Type 2 Oral Poliovirus Vaccine Strain.

Delays in achieving the global eradication of wild poliovirus transmission continue to postpone subsequent cessation of all oral poliovirus vaccine (OPV) use. Countries must stop OPV use to end all cases of poliomyelitis, including vaccine-associated paralytic polio (VAPP) and cases caused by vaccine-derived polioviruses (VDPVs). The Global Polio Eradication Initiative (GPEI) coordinated global cessation of all type 2 OPV (OPV2) use in routine immunization in 2016 but did not successfully end the transmission of type 2 VDPVs (VDPV2s), and consequently continues to use type 2 OPV (OPV2) for outbreak response activities. Using an updated global poliovirus transmission and OPV evolution model, we characterize outbreak response options for 2019-2029 related to responding to VDPV2 outbreaks with a genetically stabilized novel OPV (nOPV2) strain or with the currently licensed monovalent OPV2 (mOPV2). Given uncertainties about the properties of nOPV2, we model different assumptions that appear consistent with the evidence on nOPV2 to date. Using nOPV2 to respond to detected cases may reduce the expected VDPV and VAPP cases and the risk of needing to restart OPV2 use in routine immunization compared to mOPV2 use for outbreak response. The actual properties, availability, and use of nOPV2 will determine its effects on type 2 poliovirus transmission in populations. Even with optimal nOPV2 performance, countries and the GPEI would still likely need to restart OPV2 use in routine immunization in OPV-using countries if operational improvements in outbreak response to stop the transmission of cVDPV2s are not implemented effectively.

[COVID-19 and vaccination: a global disruption]. / COVID-19 et vaccination : une dérégulation globale.

Coronavirus disease (COVID)-19 is an emerging pandemic infection whose significant ability to spread in a naïve population is well established. The first response of states to the COVID-19 outbreak was to impose lock-down and social barrier measures, such as wearing a surgical mask or social distancing. One of the consequences of this pandemic in terms of public health was the suspension or slowdown of infant vaccination campaigns, in almost all countries. The indirect effects of COVID-19 may therefore weigh on mortality from measles and polio in developing countries. In this pandemic chaos, the only hope lies in the rapid development of an effective vaccine against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). However, acceptance of this vaccine has not yet been won, as beyond the many unknowns that will inevitably weigh around such rapid development, skepticism among vaccine hesitants is growing.

TITLE: COVID-19 et vaccination : une dérégulation globale. ABSTRACT: La COVID-19 est une infection pandémique émergente dont l'importante capacité à se propager dans une population dénuée d'immunité n'est plus à prouver. La première réponse des États à la flambée de COVID-19 fut d'imposer un confinement et des mesures barrières, telles que le port du masque et la distanciation sociale. Une des répercussions de cette pandémie, en matière de santé publique, fut la suspension ou le ralentissement brusque des campagnes de vaccination des nourrissons, un peu partout dans le monde. Un des effets indirects de la COVID-19 est donc le risque de peser sur la mortalité mondiale, principalement via une recrudescence de la rougeole et de la poliomyélite, principalement dans les pays en voie de développement. Dans ce chaos potentiel, le seul espoir réside dans le développement rapide d'un vaccin efficace contre le SARS-CoV-2 (severe acute respiratory syndrome-coronavirus-2). Cependant, l'acceptation de ce vaccin par la population n'est pas évidente, car outre les nombreuses inconnues qui vont peser inévitablement dans le cas d'un développement très rapide du vaccin, le scepticisme des hésitants vaccinaux va à nouveau se développer.

Polio in Afghanistan: The Current Situation amid COVID-19.

Polio is a deadly viral disease that has been paralyzing many children in Afghanistan. Despite fundamental efforts, primarily vaccination, to reduce the number of cases in Afghanistan, there are still many children who are deprived of the vaccine every year. Afghanistan is one of the two remaining countries endemic for polio, and the country has undergone various challenges that have hampered the eradication of this disease. The underlying challenges include inaccessibility of unsecured areas, illiteracy, refusal, and, most recently, COVID-19. The country is in the midst of a battle against COVID-19, and polio has almost entirely been neglected. Sadly, polio cases are increasing in the country, particularly in polio-free provinces. After an initial lockdown, many businesses have been allowed to resume, but the mass polio vaccination campaign has not restarted. New cases of polio will surge if endemic regions remain unvaccinated or inaccessible. To curb the further spread of polio, Afghanistan needs to resume nationwide house-to-house vaccination as restrictions due to COVID-19 are loosened.