Exploratory analysis of immunization records highlights decreased SARS-CoV-2 rates in individuals with recent non-COVID-19 vaccinations.

Clinical studies are ongoing to assess whether existing vaccines may afford protection against SARS-CoV-2 infection through trained immunity. In this exploratory study, we analyze immunization records from 137,037 individuals who received SARS-CoV-2 PCR tests. We find that polio, Haemophilus influenzae type-B (HIB), measles-mumps-rubella (MMR), Varicella, pneumococcal conjugate (PCV13), Geriatric Flu, and hepatitis A/hepatitis B (HepA-HepB) vaccines administered in the past 1, 2, and 5 years are associated with decreased SARS-CoV-2 infection rates, even after adjusting for geographic SARS-CoV-2 incidence and testing rates, demographics, comorbidities, and number of other vaccinations. Furthermore, age, race/ethnicity, and blood group stratified analyses reveal significantly lower SARS-CoV-2 rate among black individuals who have taken the PCV13 vaccine, with relative risk of 0.45 at the 5 year time horizon (n: 653, 95% CI (0.32, 0.64), p-value: 6.9e-05). Overall, this study identifies existing approved vaccines which can be promising candidates for pre-clinical research and Randomized Clinical Trials towards combating COVID-19.

[Discovery of Foci of Type-2 Poliovirus Derived from Oral Polio Vaccine in Central African Republic in 2019]. / Découverte de Foyers de Poliovirus de Type-2 Dérivé du Vaccin Antipoliomyélitique Oral en République Centrafricaine en 2019.

Objective: In 2019, the Central African Republic identified foci of circulating vaccine-derived poliovirus 2 (PVDV2c). The objective of this work is to describe the vaccination status of children paralyzed by PVDV2c and their contacts and to assess the circulation of this strain in these contacts. Patients and method: The study population of this retrospective survey consists of children with acute flaccid paralysis (AFP) and their contacts. We included paralyzed children whose sequencing results showed the presence of PVDV2c. Results: A total of 21 children paralyzed by PVDVc and 64 contacts were enrolled in the survey. Fourteen out of 21 children who are paralyzed (66%) received at least one dose of bivalent oral polio vaccine (OPV) compared to 36 out of 64 contacts (57%, non-significant difference). Of the vaccinated patients, 7 had received less than three doses. For the injectable polio vaccine (IPV), vaccination coverage for both patients and contacts was 33%.The proportion of children who received both doses of OPV and IPV was 33% among patients and 25% in contacts. Contacts with VDPV2 were vaccinated with OPV and IPV, respectively 55 and 27%. VDPV2 and Sabin 2 were also found in contact stools, 34% and 9% respectively. Conclusion: The absence or inadequacy of IPV vaccination has a serious impact on children by the occurrence of virus derived from the vaccine responsible for life-old paralysis. Protecting children from poliomyelitis requires a combination of a good cold chain, multiple doses and adherence to the vaccine schedule.

The experiences of using polio outbreak simulation exercises to strengthen national outbreaks preparedness and response plans in sub-Saharan Africa.

INTRODUCTION: globally, by 2020 the paralytic poliomyelitis disease burden decreased to over 99% of the reported cases in 1988 when resolution 41.8 was endorsed by the World Health Assembly (WHA) for global polio eradication. It is clearly understood that, if there is Wild Poliovirus (WPV) and circulating Vaccines Derived Poliovirus (cVDPV) in the world, no country is safe from polio outbreaks. All countries remain at high risk of re-importation depending on the level of the containment of the types vaccine withdrawn, the laboratory poliovirus isolates, and the population immunity induced by the vaccination program. In this regard, countries to have polio outbreak preparedness and response plans, and conducting the polio outbreak simulation exercises for these plans remain important. METHODS: we conducted a cross-section qualitative study to review to 8 countries conducted polio outbreak simulation exercises in the East and Southern Africa from 2016 to 2018. The findings were categorized into 5 outbreak response thematic areas analyzed qualitatively and summarized them on their strengths and weaknesses. RESULTS: we found out that, most countries have the overall technical capacities and expertise to deal with outbreaks to a certain extent. Nevertheless, we noted that the national polio outbreak preparedness and response plans were not comprehensive enough to provide proper guidance in responding to outbreaks. The guidelines were inadequately aligned with the WHO POSOPs, and IHR 2005. Additionally, most participants who participated in the simulation exercises were less familiar with their preparedness and response plans, the WHO POSOPs, and therefore reported to be sensitized. CONCLUSION: we also realized that, in all countries where the polio simulation exercise conducted, their national polio outbreak preparedness and response plan was revised to be improved in line with the WHO POSOPs and IHR 2005. we, therefore, recommend the polio outbreak simulation exercises to be done in every country with an interval of 3-5 years.

Final frontiers of the polio eradication endgame.

PURPOSE OF REVIEW: Focusing on the key developments since January 2019, this review aims to inform policymakers and clinical practitioners on the latest on evolving global polio epidemiology and scientific advancements to guide strategies for eradication. RECENT FINDINGS: An upsurge in wild poliovirus type 1 cases in Pakistan and Afghanistan and an expansion of type 2 circulating vaccine-derived poliovirus transmission in multiple countries threaten the remarkable progress made over past several decades by the global eradication program. These challenges have also spurred innovation on multiple fronts, including earlier detection, enhanced environmental surveillance and safer and more affordable vaccine options. SUMMARY: A concerted effort to adapt program strategies to address context-specific challenges and continued focus on innovations to enhance detection and response capabilities will be the key to achieve and sustain eradication of all types of polioviruses.

Narrativas vacunales y políticas de vacunación contra la poliomielitis en el contexto de la provincia de Alicante (1963-1978) / Vaccine narratives and polio vaccination policies in the context of the province of Alicante (1963-1978)

El análisis a pequeña escala es una vía de abordaje historiográfico que abrió, en su momento, nuevos caminos en la investigación. La proximidad del objeto de estudio, permite profundizar en los determinantes propios y específicos y en las realidades y prácticas, por ejemplo, de las campañas de inmunización masiva contra la poliomielitis diseñada a nivel nacional pero implementadas localmente, como en el estudio de caso que abordamos. Utilizando como modelo el ámbito sanitario provincial de Alicante, el trabajo añade datos para completar la información de proximidad sobre estas campañas y de ese modo, completar una visión de conjunto y un análisis comparado tanto en un ámbito externo como en un ámbito interno interterritorial, nacional y provincial, así como el seguimiento de las directrices dadas por los organismos nacionales e internacionales. En segundo término, dotar de significado al conjunto de actividades llevadas a cabo por diferentes actores, instituciones y medios de comunicación, implicados en el proceso de implantación, cobertura y seguimiento de las campañas de vacunación contra la polio en el ámbito provincial alicantino. El uso de narrativas de personas afectadas por la enfermedad permite añadir elementos relevantes sobre experiencias personales en el contexto de las campañas vacunales

Small-scale analysis is a path of historiographical approach that opened, at the time, new paths in research. The proximity of the study object allows us to delve into our own and specific determinants and the realities and practices of, for example, mass immunization campaigns against polio, designed at the national level but implemented locally, as in the case study that we discuss. Using as a model the provincial sanitary area of Alicante, the work adds data to complete the proximity information on these campaigns and thus, complete an overview and a comparative analysis both in an external and in an internal interterritorial, national scope and provincial level as well as the follow-up of the guidelines given by the national and international organisms. Secondly, to give meaning to the set of activities carried out by different actors, institutions and media, involved in the process of implementation, coverage and follow-up of polio vaccination campaigns in the province of Alicante. The use of narratives of people affected by the disease allows to add relevant elements about personal experiences in the context of the vaccine campaigns

Vaccine hesitancy and (fake) news: Quasi-experimental evidence from Italy.

The spread of fake news and misinformation on social media is blamed as a primary cause of vaccine hesitancy, which is one of the major threats to global health, according to the World Health Organization. This paper studies the effect of the diffusion of misinformation on immunization rates in Italy by exploiting a quasi-experiment that occurred in 2012, when the Court of Rimini officially recognized a causal link between the measles-mumps-rubella vaccine and autism and awarded injury compensation. To this end, we exploit the virality of misinformation following the 2012 Italian court's ruling, along with the intensity of exposure to nontraditional media driven by regional infrastructural differences in Internet broadband coverage. Using a Difference-in-Differences regression on regional panel data, we show that the spread of this news resulted in a decrease in child immunization rates for all types of vaccines.

Finding inhabited settlements and tracking vaccination progress: the application of satellite imagery analysis to guide the immunization response to confirmation of previously-undetected, ongoing endemic wild poliovirus transmission in Borno State, Nigeria.

BACKGROUND: Four wild polio-virus cases were reported in Borno State, Nigeria 2016, 1 year after Nigeria had been removed from the list of polio endemic countries by the World Health Organization. Resulting from Nigeria's decade long conflict with Boko Haram, health officials had been unable to access as much as 60% of the settlements in Borno, hindering vaccination and surveillance efforts. This lack of accessibility made it difficult for the government to assess the current population distribution within Borno. This study aimed to use high resolution, visible band satellite imagery to assess the habitation of inaccessible villages in Borno State. METHODS: Using high resolution (31-50 cm) imagery from DigitalGlobe, analysts evaluated the habitation status of settlements in Borno State identified by Nigeria's Vaccination Tracking System. The analysts looked at imagery of each settlement and, using vegetation (overgrowth vs. cleared) as a proxy for human habitation, classified settlements into three categories: inhabited, partially abandoned, and abandoned. Analysts also classified the intact percentage of each settlement starting at 0% (totally destroyed since last assessment) and increasing in 25% intervals through 100% (completely intact but not expanded) up to 200+% (more than doubled in size) by looking for destroyed buildings. These assessments were then used to adjust previously established population estimates for each settlement. These new population distributions were compared to vaccination efforts to determine the number of children under 5 unreached by vaccination teams. RESULTS: Of the 11,927 settlements assessed 3203 were assessed as abandoned (1892 of those completely destroyed), 662 as partially abandoned, and 8062 as fully inhabited as of December of 2017. Comparing the derived population estimates from the new assessments to previous assessment and the activities of vaccination teams shows that an estimated 180,155 of the 337,411 under five children who were unreached in 2016 were reached in 2017 (70.5% through vaccination efforts in previously inaccessible areas, 29.5% through displacement to accessible areas). CONCLUSIONS: This study's methodology provides important planning and situation awareness information to health workers in Borno, Nigeria, and may serve as a model for future data gathering efforts in inaccessible regions.

Progress of polio eradication and containment requirements after eradication.

Wild poliovirus (WPV) is nearing eradication, and only three countries have never interrupted WPV transmission (Pakistan, Afghanistan, and Nigeria). WPV2 was last detected in 1999, and it was declared eradicated in 2015. WPV3 has not been detected since 2012. Since 2016, WPV1 has been detected in only two countries (Afghanistan and Pakistan), with only 22 cases reported in 2017 and 12 cases reported in 2018 (as of July 10). Because of WPV2 eradication and the risk of emergence of type 2 vaccine-derived polioviruses from continued use of trivalent oral polio vaccine (OPV), trivalent OPV was replaced by bivalent OPV (types 1 and 3) in a globally coordinated effort in 2016. WPV2 eradication and trivalent OPV cessation also mean that breach of containment in a facility working with type 2 poliovirus is now a major risk to reseed type 2 circulation in the community. As a result, the World Health Organization has developed a "Global Action Plan to minimize poliovirus facility-associated risk after type-specific eradication of wild polioviruses and sequential cessation of oral polio vaccine use." Because poliovirus has long been used as a standard for qualification of intravenous immunoglobulin, disinfectant products, and sanitation methods, poliovirus containment has implications far beyond poliovirus laboratories.

The effect of maternal decisional authority on children's vaccination in East Asia.

Even though they are important determinants for increasing vaccination rates in advanced and developing nations alike, maternal capacity and decisional authority have not been fully elucidated in diverse countries and cultural spheres. This study examined the effects of South Korean, Chinese, and Japanese mothers' health literacy, self-efficacy, mass media use, and decisional authority on their children's vaccination after adjustment for their socioeconomic statuses. Computer-assisted web interviews were conducted with married women in their 20s-40s of South Korean, Chinese, or Japanese nationality (n = 1,571). Dependent variables were generated for the following four vaccinations: BCG, diphtheria+pertussis+tetanus (DPT), poliomyelitis (polio), and measles. For statistical processing, cases where all four types of vaccines had been recorded were scored as 1 and other cases were processed as 0. According to the results of the pooled model, we found that for East Asian mothers, decisional authority, self-efficacy, and health literacy all increased the likelihood that they would vaccinate their children. Furthermore, women who searched for health information through media such as the radio were more likely to vaccinate their children. However, when elaborate analyses were conducted by country, there were considerable differences in those characteristics by country. Therefore, this study showed that it is necessary to establish locally tailored strategies in order to raise vaccination rates in the Global Vaccine Action Plan. This study also showed that social contexts must be taken into consideration in order to raise vaccination rates.

Factors associated with routine immunization coverage of children under one year old in Lao People's Democratic Republic.

BACKGROUND: Routine vaccination is administered free of charge to all children under one year old in Lao People's Democratic Republic (Lao PDR) and the national goal is to achieve at least 95% coverage with all vaccines included in the national immunization program by 2025. In this study, factors related to the immunization system and characteristics of provinces and districts in Lao PDR were examined to evaluate the association with routine immunization coverage. METHODS: Coverage rates for Bacillus Calmette-Guerin (BCG), Diphtheria-Tetanus-Pertussis-Hepatitis B (DTP-HepB), DTP-HepB-Hib (Haemophilus influenzae type B), polio (OPV), and measles (MCV1) vaccines from 2002 to 2014 collected through regular reporting system, were used to identify the immunization coverage trends in Lao PDR. Correlation analysis was performed using immunization coverage, characteristics of provinces or districts (population, population density, and proportion of poor villages and high-risk villages), and factors related to immunization service (including the proportions of the following: villages served by health facility levels, vaccine session types, and presence of well-functioning cold chain equipment). To determine factors associated with low coverage, provinces were categorized based on 80% of DTP-HepB-Hib3 coverage (<80% = low group; ≥80% = high group). RESULTS: Coverages of BCG, DTP-HepB3, OPV3 and MCV1 increased gradually from 2007 to 2014 (82.2-88.3% in 2014). However, BCG coverage showed the least improvement from 2002 to 2014. The coverage of each vaccine correlated with the coverage of the other vaccines and DTP-HepB-Hib dropout rate in provinces as well as districts. The provinces with low immunization coverage were correlated with higher proportions of poor villages. CONCLUSIONS: Routine immunization coverage has been improving in the last 13 years, but the national goal is not yet reached in Lao PDR. The results of this study suggest that BCG coverage and poor villages should be targeted to improve nationwide coverage.

Seronegativity to polio viruses among previously immunized adult candidates to solid organ transplantation.

In the current effort to eliminate polio from the world, it is important to recognize and vaccinate susceptible groups, especially immunocompromised patients living in countries where attenuated polio vaccine is still used. In this report, we describe the frequency of protective antibodies in a small sample of adult SOT candidates in whom previous vaccination could be ascertained. Patients included in this report were selected among the participants of an ongoing prospective study carried out at the Reference Center for Special Immunobiologicals of the Evandro Chagas National Institute of Infectious Diseases in Rio de Janeiro, Brazil. Among the first 100 patients enrolled in this study, only seven adult SOT candidates had proven polio vaccination at childhood. Three of these seven patients (43%) had no protective antibody titers to one or more poliovirus subtype before solid organ transplant. Proven childhood vaccination against polio does not reliably provide lifelong protective antibody titers for adult SOT candidates and should not be used as a criterion to analyze the need for vaccination in this population.

Seronegativity to polio viruses among previously immunized adult candidates to solid organ transplantation

ABSTRACT In the current effort to eliminate polio from the world, it is important to recognize and vaccinate susceptible groups, especially immunocompromised patients living in countries where attenuated polio vaccine is still used. In this report, we describe the frequency of protective antibodies in a small sample of adult SOT candidates in whom previous vaccination could be ascertained. Patients included in this report were selected among the participants of an ongoing prospective study carried out at the Reference Center for Special Immunobiologicals of the Evandro Chagas National Institute of Infectious Diseases in Rio de Janeiro, Brazil. Among the first 100 patients enrolled in this study, only seven adult SOT candidates had proven polio vaccination at childhood. Three of these seven patients (43%) had no protective antibody titers to one or more poliovirus subtype before solid organ transplant. Proven childhood vaccination against polio does not reliably provide lifelong protective antibody titers for adult SOT candidates and should not be used as a criterion to analyze the need for vaccination in this population.

Vaccine-derived poliovirus surveillance in China during 2001-2013: the potential challenge for maintaining polio free status.

BACKGROUND: The goal of polio eradication is to complete elimination and containment of all wild, vaccine-related and Sabin polioviruses. Vaccine-derived poliovirus (VDPV) surveillance in China from 2001-2013 is summarized in this report, which has important implications for the global polio eradication initiative. METHODS: Acute flaccid paralysis (AFP) cases and their contacts with VDPVs isolated from fecal specimens were identified in our AFP surveillance system or by field investigation. Epidemiological and laboratory information for these children were analyzed and the reasons for the VDPV outbreak was explored. RESULTS: VDPVs were isolated from a total of 49 children in more than two-thirds of Chinese provinces from 2001-2013, including 15 VDPV cases, 15 non-polio AFP cases and 19 contacts of AFP cases or healthy subjects. A total of 3 circulating VDPVs (cVDPVs) outbreaks were reported in China, resulting in 6 cVDPVs cases who had not been vaccinated with oral attenuated poliomyelitis vaccine. Among the 4 immunodeficiency-associated VDPVs (iVDPVs) cases, the longest duration of virus excretion was about 20 months. In addition, one imported VDPV case from Myanmar was detected in Yunnan Province. CONCLUSIONS: Until all wild, vaccine-related and Sabin polioviruses are eradicated in the world, high quality routine immunization and sensitive AFP surveillance should be maintained, focusing efforts on underserved populations in high risk areas.

Expansion of Vaccination Services and Strengthening Vaccine-Preventable Diseases Surveillance in Haiti, 2010-2016.

Following the 2010 earthquake, Haiti was at heightened risk for vaccine-preventable diseases (VPDs) outbreaks due to the exacerbation of long-standing gaps in the vaccination program and subsequent risk of VPD importation from other countries. Therefore, partners supported the Haitian Ministry of Health and Population to improve vaccination services and VPD surveillance. During 2010-2016, three polio, measles, and rubella vaccination campaigns were implemented, achieving a coverage > 90% among children and maintaining Haiti free of those VPDs. Furthermore, Haiti is on course to eliminate maternal and neonatal tetanus, with 70% of communes achieving tetanus vaccine two-dose coverage > 80% among women of childbearing age. In addition, the vaccine cold chain storage capacity increased by 91% at the central level and 285% at the department level, enabling the introduction of three new vaccines (pentavalent, rotavirus, and pneumococcal conjugate vaccines) that could prevent an estimated 5,227 deaths annually. Haiti moved from the fourth worst performing country in the Americas in 2012 to the sixth best performing country in 2015 for adequate investigation of suspected measles/rubella cases. Sentinel surveillance sites for rotavirus diarrhea and meningococcal meningitis were established to estimate baseline rates of those diseases prior to vaccine introduction and to evaluate the impact of vaccination in the future. In conclusion, Haiti significantly improved vaccination services and VPD surveillance. However, high dependence on external funding and competing vaccination program priorities are potential threats to sustaining the improvements achieved thus far. Political commitment and favorable economic and legal environments are needed to maintain these gains.

Understanding 'perceptions' is critical for all vaccination efforts, not only polio eradication.

Because Pakistan is the country with the most daunting challenges for ending transmission of endemic poliovirus, the work of Habib et al in this issue is critical for achieving polio eradication globally. Understanding why immunization programs are not reaching all children is important for success in reducing spread of all vaccine preventable diseases. The methods and insights are important for public health generalists, not only those employed in the pursuit of polio eradication.