Response to Vaccine-Derived Polioviruses Detected through Environmental Surveillance, Guatemala, 2019.

Guatemala implemented wastewater-based poliovirus surveillance in 2018, and three genetically unrelated vaccine-derived polioviruses (VDPVs) were detected in 2019. The Ministry of Health (MoH) response included event investigation through institutional and community retrospective case searches for acute flaccid paralysis (AFP) during 2018-2020 and a bivalent oral polio/measles, mumps, and rubella vaccination campaign in September 2019. This response was reviewed by an international expert team in July 2021. During the campaign, 93% of children 6 months <7 years of age received a polio-containing vaccine dose. No AFP cases were detected in the community search; institutional retrospective searches found 37% of unreported AFP cases in 2018‒2020. No additional VDPV was isolated from wastewater. No evidence of circulating VDPV was found; the 3 isolated VDPVs were classified as ambiguous VDPVs by the international team of experts. These detections highlight risk for poliomyelitis reemergence in countries with low polio vaccine coverage.

Achieving high immunogenicity against poliovirus with fractional doses of inactivated poliovirus vaccine in Ecuador-results from a cross-sectional serological survey.

Background: In January 2018, Ecuador changed its routine immunization schedule by replacing one full dose of inactivated poliovirus vaccine (IPV) administered intramuscularly at 2 months of age with two doses of fractional IPV (1/5th of full dose, fIPV) administered intradermally at 2 and 4 months of age; and bivalent oral poliovirus vaccine (serotypes 1 and 3, bOPV) continues to be used. We compared seroprevalence and titres of polio antibodies achieved by the past and the current immunization schedules. Methods: This was a cross-sectional serological survey in children in Ecuador who received bOPV and either one IPV dose in 2017 or two fIPV doses in 2018. One blood sample was collected between October 2020 and March 2021 and analysed for presence of poliovirus neutralizing antibodies at CDC, Atlanta by microneutralization assay. Findings: We obtained 321 analysable samples from 329 (97·6%) enrolled children (160 received IPV and 161 fIPV). For serotype 2, seroprevalence was 50·0% (CI95%= 44·2-55·8%) for IPV and 83·2% (CI95%=78·5-87·1%) for fIPV recipients (p<0·001). Median antibody titers for serotype 2 were significantly lower for IPV than for fIPV recipients (3·0, CI95%= 3 - 3·5 vs. 4·8, CI95%= 4·5 - 5·2, p<0·001). Seroprevalence for serotypes 1 and 3 was above 90% and was not significantly different between IPV and fIPV recipients. Interpretation: Ecuador achieved significantly better poliovirus serotype 2 immunogenicity with two fIPV doses than with one IPV dose, while preserving vaccine supply and reducing costs. Our data provide further evidence that fIPV is a beneficial and potentially a cost-effective option in polio immunization. Funding: WHO obtained funds for the study from Rotary International.

The path towards polio eradication over 40 years of the Expanded Program on Immunization in the Americas

[ABSTRACT]. This article synthesizes the important lessons learned from polio eradication in the Region of the Americas, including initial and more recent challenges and best practices, as well as particular factors surrounding attainment of this ambitious goal. Using documents, interviews, and country surveys, the authors describe and analyze the strategies and lessons learned during the 40 years of the Expanded Program on Immunization (1977 – 2017). Some major milestones and challenges specifically covered are: the Vaccine-derived Poliovirus (VDPV) outbreak in the Dominican Republic; the regional “mop-up operation;” poliovirus containment in essential facilities; the unprecedented introduction of inactivated polio vaccine (IPV); the synchronized switch from trivalent to bivalent OPV; and the countries’ unfailing commitment to the cause.

[RESUMEN]. En este artículo se sintetizan las importantes enseñanzas extraídas de la erradicación de la poliomielitis en la Región de las Américas. Se presta especial atención a los retos y las mejores prácticas que se abordaron en un principio y a los más recientes, así como a los factores particulares que han girado en torno al logro de esta meta de gran alcance. Por medio de documentos, entrevistas y encuestas nacionales, las autoras describen y analizan las estrategias y enseñanzas extraídas a lo largo de los 40 años del Programa Ampliado de Inmunización (1977–2017). Entre los hitos y retos más importantes que se abordan en el artículo se encuentran los siguientes: el brote del poliovirus derivado de la vacuna en la República Dominicana; la campaña de vacunación “de seguimiento” a nivel regional; la contención del poliovirus en las instalaciones esenciales; la introducción sin precedentes de la vacuna antipoliomielítica con virus inactivados (VPI); el cambio sincronizado de la vacuna antipoliomielítica oral trivalente por la vacuna antipoliomielítica oral bivalente (conocido como “el switch”); y el compromiso inquebrantable de los países con esta causa.

[RESUMO]. Este artigo sintetiza os principais ensinamentos da erradicação da poliomielite na Região das Américas, expondo as dificuldades enfrentadas ao início e em um período mais recente, as boas práticas e os fatores inerentes relacionados ao alcance desta meta ambiciosa. A partir de documentos, entrevistas e levantamentos nos países, os autores descrevem e analisam as estratégias empregadas e a experiência obtida ao longo dos 40 anos do Programa Ampliado de Imunização (1977–2017). Entre os marcos e os desafios importantes abordados estão: o surto por vírus da poliomielite derivado da vacina (VDPV) na República Dominicana, a operação regional de “acabamento’’, a contenção do poliovírus em laboratório, a introdução inédita da vacina contra poliomielite com vírus inativado (VPI), a transição sincronizada da vacina oral contra poliomielite trivalente à bivalente e o firme compromisso dos países com a causa.

The path towards polio eradication over 40 years of the Expanded Program on Immunization in the Americas.

This article synthesizes the important lessons learned from polio eradication in the Region of the Americas, including initial and more recent challenges and best practices, as well as particular factors surrounding attainment of this ambitious goal. Using documents, interviews, and country surveys, the authors describe and analyze the strategies and lessons learned during the 40 years of the Expanded Program on Immunization (1977 - 2017). Some major milestones and chxallenges specifically covered are: the Vaccine-derived Poliovirus (VDPV) outbreak in the Dominican Republic; the regional "mop-up operation;" poliovirus containment in essential facilities; the unprecedented introduction of inactivated polio vaccine (IPV); the synchronized switch from trivalent to bivalent OPV; and the countries' unfailing commitment to the cause.

En este artículo se sintetizan las importantes enseñanzas extraídas de la erradicación de la poliomielitis en la Región de las Américas. Se presta especial atención a los retos y las mejores prácticas que se abordaron en un principioy a los más recientes, así como a los factores particulares que han girado en torno al logro de esta meta de gran alcance. Por medio de documentos, entrevistas y encuestas nacionales, las autoras describen y analizan las estrategias y enseñanzas extraídas a lo largo de los 40 años del Programa Ampliado de Inmunización (1977­2017). Entre los hitos y retos más importantes que se abordan en el artículo se encuentran los siguientes: el brote del poliovirus derivado de la vacuna en la República Dominicana; la campaña de vacunación "de seguimiento" a nivel regional; la contención del poliovirus en las instalaciones esenciales; la introducción sin precedentes de la vacuna antipoliomielítica con virus inactivados (VPI); el cambio sincronizado de la vacuna antipoliomielítica oral trivalente por la vacuna antipoliomielítica oral bivalente (conocido como "el switch"); y el compromiso inquebrantable de los países con esta causa.

Este artigo sintetiza os principais ensinamentos da erradicação da poliomielite na Região das Américas, expondo as dificuldades enfrentadas ao início e em um período mais recente, as boas práticas e os fatores inerentes relacionados ao alcance desta meta ambiciosa. A partir de documentos, entrevistas e levantamentos nos países, os autores descrevem e analisam as estratégias empregadas e a experiência obtida ao longo dos 40 anos do Programa Ampliado de Imunização (1977­2017). Entre os marcos e os desafios importantes abordados estão: o surto por vírus da poliomielite derivado da vacina (VDPV) na República Dominicana, a operação regional de "acabamento", a contenção do poliovírus em laboratório, a introdução inédita da vacina contra poliomielite com vírus inativado (VPI), a transição sincronizada da vacina oral contra poliomielite trivalente à bivalente e o firme compromisso dos países com a causa.

The path towards polio eradication over 40 years of the Expanded Program on Immunization in the Americas / El camino hacia la erradicación de la poliomielitis en los 40 años del Programa Ampliado de Inmunización en la Región de las Américas / Trajetória da erradicação da poliomielite ao longo dos 40 anos do Programa Ampliado de Imunização nas Américas

SUMMARY This article synthesizes the important lessons learned from polio eradication in the Region of the Americas, including initial and more recent challenges and best practices, as well as particular factors surrounding attainment of this ambitious goal. Using documents, interviews, and country surveys, the authors describe and analyze the strategies and lessons learned during the 40 years of the Expanded Program on Immunization (1977 - 2017). Some major milestones and challenges specifically covered are: the Vaccine-derived Poliovirus (VDPV) outbreak in the Dominican Republic; the regional "mop-up operation;" poliovirus containment in essential facilities; the unprecedented introduction of inactivated polio vaccine (IPV); the synchronized switch from trivalent to bivalent OPV; and the countries' unfailing commitment to the cause.

RESUMEN En este artículo se sintetizan las importantes enseñanzas extraídas de la erradicación de la poliomielitis en la Región de las Américas. Se presta especial atención a los retos y las mejores prácticas que se abordaron en un principio y a los más recientes, así como a los factores particulares que han girado en torno al logro de esta meta de gran alcance. Por medio de documentos, entrevistas y encuestas nacionales, las autoras describen y analizan las estrategias y enseñanzas extraídas a lo largo de los 40 años del Programa Ampliado de Inmunización (1977-2017). Entre los hitos y retos más importantes que se abordan en el artículo se encuentran los siguientes: el brote del poliovirus derivado de la vacuna en la República Dominicana; la campaña de vacunación "de seguimiento" a nivel regional; la contención del poliovirus en las instalaciones esenciales; la introducción sin precedentes de la vacuna antipoliomielítica con virus inactivados (VPI); el cambio sincronizado de la vacuna antipoliomielítica oral trivalente por la vacuna antipoliomielítica oral bivalente (conocido como "el switch"); y el compromiso inquebrantable de los países con esta causa.

RESUMO Este artigo sintetiza os principais ensinamentos da erradicação da poliomielite na Região das Américas, expondo as dificuldades enfrentadas ao início e em um período mais recente, as boas práticas e os fatores inerentes relacionados ao alcance desta meta ambiciosa. A partir de documentos, entrevistas e levantamentos nos países, os autores descrevem e analisam as estratégias empregadas e a experiência obtida ao longo dos 40 anos do Programa Ampliado de Imunização (1977-2017). Entre os marcos e os desafios importantes abordados estão: o surto por vírus da poliomielite derivado da vacina (VDPV) na República Dominicana, a operação regional de "acabamento", a contenção do poliovírus em laboratório, a introdução inédita da vacina contra poliomielite com vírus inativado (VPI), a transição sincronizada da vacina oral contra poliomielite trivalente à bivalente e o firme compromisso dos países com a causa.

Progress Toward Poliomyelitis Eradication--Nigeria, January 2014-July 2015.

Since the 1988 launch of global poliomyelitis eradication efforts, four of the six World Health Organization (WHO) regions have been certified polio-free. Nigeria is one of only three countries, along with Afghanistan and Pakistan, where transmission of wild poliovirus (WPV) has never been interrupted. During 2003-2013, northern Nigeria served as a reservoir for WPV reintroduction into 26 previously polio-free countries. In 2012, the Nigerian government launched a national polio eradication emergency plan to intensify efforts to interrupt WPV transmission. This report describes polio eradication activities and progress in Nigeria during January 2014-July 2015 and updates previous reports. No WPV cases have been reported to date in 2015, compared with a total of six cases reported during 2014. Onset of paralysis in the latest reported WPV type 1 (WPV1) case was July 24, 2014. Only one case of circulating vaccine-derived poliovirus type 2 (cVDPV2) has been reported to date in 2015, compared with 20 cVDPV2 cases during the same period in 2014. Pending final laboratory testing of 218 remaining specimens of 16,617 specimens collected since January 2015, Nigeria could be removed from the WHO list of polio-endemic countries in September 2015. Major remaining challenges to the national polio eradication program include sustaining political support and program funding in the absence of active WPV transmission, maintaining high levels of population immunity in hard-to-reach areas, and accessing children in security-compromised areas of the northeastern states.

Advocacy and resource mobilization for rubella elimination in Guatemala.

This review describes the advocacy efforts to mobilize resources for the campaign to vaccinate men and women aged 9-39 years, with a goal of eliminating rubella and congenital rubella syndrome in Guatemala. The country's investment in health has been historically low (0.9% of gross domestic product), and there has been a wide gap between the availability of economic resources and the need for economic resources for the immunization campaign. The review contains a summary of the investment made, the results of advocacy and resource mobilization, the vaccination coverage attained, and the campaign's impact on the disease.

Rubella vaccination of unknowingly pregnant women during mass campaigns for rubella and congenital rubella syndrome elimination, the Americas 2001-2008.

BACKGROUND: Due to the significant teratogenicity of rubella virus and the use of a live-attentuated vaccine, pregnancy is a contraindication of receipt of rubella vaccine (RCV). Data collected from several countries that have observed susceptible women who had received RCV during pregnancy documented that no infant with congenital rubella syndrome (CRS) has been born, so the risk is theoretical. As part of the regional initiative to eliminate rubella and CRS in the Americas, one of the key strategies was the vaccination of women of childbearing age. The implementation of mass vaccination campaigns targeting women of childbearing age in Argentina, Brazil, Costa Rica, Ecuador, El Salvador, and Paraguay provided an opportunity to further increase the body of knowledge on the safety of rubella vaccine if an unknowingly pregnant woman is vaccinated in early pregnancy. METHODS: Using a standard protocol, women who were unknowingly pregnant or become pregnant ≤ 30 days after receiving RCV were evaluated to determine immunity status (eg, susceptible, immune, and unknown) at the time of vaccination. Susceptible pregnant women were observed to determine the outcome of the pregnancy. For pregnancies that resulted in live births, serum samples were obtained from the newborn for rubella immunoglobulin (Ig) M antibody testing. If the newborn's serum sample was IgM positive, the infant was evaluated for manifestations of CRS. RESULTS: During the period 2001-2008, 48748253 women of childbearing age were vaccinated in the region of the Americas, 39542253 (81%) of whom were vaccinated in the 6 selected countries. Of these women, 30139 (0.07%) were pregnant or became pregnant ≤1 month after receiving vaccine and were followed up. On the basis of serological evaluation, 2894 (10%) women were classified as susceptible at the time of vaccination; of their pregnancies, 1980 (90%) resulted in a live birth. Sera from 70 (3.5%) of these infants were rubella IgM antibody positive, but none of the infants had features of CRS as a result of rubella vaccination. The maximum theoretical risk for CRS following rubella vaccination of susceptible pregnant women was 0.2%. Conclusions. The results of these studies from 6 select countries provides additional evidence showing an absence of risk of CRS associated with administering rubella vaccine shortly before or during pregnancy.