Remarks on the possibility of introducing the fractionated dose of the inactivated poliomyelitis vaccine in the Latin American Child Immunization Schedule

Abstract Given that the last notified case of poliomyelitis due to wild poliovirus type 2 was in 1999, in 2012, the Strategic Advisory Group of Experts on Immunization (SAGE) of the World Health Organization (WHO) recommended the withdrawal of the type 2 component of oral polio vaccine (OPV) and the introduction of a bivalent OPV (bOPV) in all countries by 2016. WHO recommended also that the withdrawal should be preceded by the introduction of at least one dose of inactivated poliovirus vaccine (IPV) in routine immunization schedules. The introduction of IPV prior to the change of the bOPV in 2016 to trivalent OPV (tOPV) was based on the concept of ensuring that a substantial proportion of the population would be protected against type 2 polio after the removal of the type 2 OPV. However, the world's two producers of IPV (Bilthoven Biologicals and Sanofi) have faced problems in the production of this vaccine and therefore reported a reduction of the global supply of IPV. In response to the potential shortage of IPV, at a meeting held on March 10 2017, the SAGE and Technical Advisory Group (TAG) of the Pan American Health Organization (PAHO) urged the countries in the Latin American region to replace the routine administration of the full doses of inactivated polio vaccine (IPV-C) in the immunization schedule (administered by intramuscular route), administering a fraction of the full dose in two intradermal shots (IPV-f). The possibility of this strategy was analyzed by opinion leaders convened by the Paraguayan Society of Pediatrics with the support of the Latin American Society of Pediatric Infectious Diseases (SLIPE) and Latin American Association of Pediatrics (ALAPE). This document presents the results of the discussion.

Consideraciones referente a la posibilidad de introducir la dosis fraccionada de la vacuna antipoliomielitis inactivada en el calendario de Inmunizaciones del Niño Latinoamericano / Remarks on the possibility of the introduction of fractionated dose of the inactivated poliomyelitis vaccine in the Latin American Child Immunization Schedule

As last notified case of poliomyelitis due to wild poliovirus type 2 was 1999, in 2012, the Strategic Advisory Group of Experts on Immunization (SAGE) of the World Health Organization (WHO) recommended the withdrawal of the type 2 component of oral polio vaccine (OPV) and the introduction of bivalent OPV (bOPV) in all countries by 2016. WHO recommended also that the withdrawal should be preceded by the introduction of at least one dose of inactivated poliovirus vaccine (IPV) in routine immunization schedules. The introduction of IPV prior to the change of the bOPV in 2016 to trivalent OPV (tOPV) was based on the concept of ensuring that a substantial proportion of the population would be protected against type 2 polio after the removal of the type 2 OPV. However, the world's two producers of IPV (Bilthoven Biologicals and Sanofi) have faced problems in the production of this vaccine and therefore reported reduction in IPV global supply. In response to the possible shortage of IPV, the SAGE and Technical Adviser Group (TAG) of the Pan American Health Organization (PAHO), in the meeting of March 10, 2017, has urged that countries in the Latinamerican region should replace the routine administration of the full doses of polio inactivated vaccine (IPV-C) in the immunization schedule (administered by intramuscular route) by the administration of a fraction of the full dose in two shots by intradermal route (IPV-f). The possibility of this strategy was analyzed by leaders of opinions gathered by the call of the Paraguayan Pediatric Society with the support of the Latin American Society of Pediatric Infectious Diseases (SLIPE) and Latin American Association of Pediatrics (ALAPE). The results of the discussion are presented in this document.

Impacto económico de la introducción de la vacuna inactivada inyectable contra la poliomielitis en Colombia / Economic impact of introducing the injectable inactivated polio vaccine in Colombia

OBJETIVOS: Evaluar la relación costo-efectividad de la introducción de la vacuna inyectable contra la poliomielitis (VIP) en Colombia con respecto al sistema actual basado en el empleo de la vacuna oral (VOP). MÉTODOS: Se diseñó un modelo de Markov basado en una cohorte hipotética de recién nacidos que recibiría la VIP o la VOP con un seguimiento de dos años y estimaciones mensuales del número de casos de poliomielitis paralítica asociada con la vacuna (PPAV). El análisis del costo se realizó desde la perspectiva del asegurador (costos a lo largo de la vida) y la sociedad (casos de PPAV evitados y años de vida ajustados por discapacidad [AVAD] evitados). RESULTADOS: Entre 1988 y 1998 se aplicaron en Colombia 22,5 millones de dosis de la VOP y se detectaron nueve casos de PPAV, para una tasa de 4,0 ¥ 10-7 por dosis. Según el modelo, se podrían esperar entre 2 y 4 casos de PPAV en los dos años de seguimiento. El costo de tratar los casos de PPAV sería de US$ 302 008, con costos de vacunación con la VOP de US$ 737 037 y de US$ 5 527 777 con la VIP. La vacunación con la VIP permitiría evitar 64 AVAD con un costo de US$ 71 062 por AVAD evitado; evitar un caso de PPAV mediante la sustitución de la VOP por la VIP costaría entre US$ 1,8 millones y US$ 2,2 millones. CONCLUSIONES: La sustitución de la VOP por la VIP no es una medida efectiva en función del costo en Colombia, incluso si se sustituyera la vacuna celular contra la tos ferina, actualmente en uso, por una vacuna acelular combinada con una VIP.

OBJECTIVE: Evaluate the cost-effectiveness of introducing the injectable inactivated polio vaccine (IPV) in Colombia versus the current system based on the use of the oral vaccine (OPV). METHODS: A Markov model was designed, based on a hypothetical cohort of newborns that would receive the IPV or the OPV vaccine, with a two-year follow-up and monthly estimates of the number of cases of vaccine-associated paralytic poliomyelitis (VAPP) that would emerge. The cost was analyzed from the perspective of the insurer (costs throughout life) and society (cases of VAPP and disability-adjusted life years [DALYs] prevented). RESULTS: From 1988 to 1998, some 22.5 million doses of OVP were administered in Colombia and nine cases of VAPP were detected, for a rate of 4.0 ¥ 10-7 dose. According to the model, 2 to 4 cases of VAPP could be anticipated in the following two years. The cost of treating the VAPP cases would total US$302 008, with the cost of vaccination with OPV coming to US$737 037 and with IPV, US$5 527 777. Vaccination with IPV would prevent 64 DALYs, at a cost of US$71 062 per DALY prevented; preventing one case of VAPP by substituting OPV with IPV would cost between US$1.8 and US$2.2 million. CONCLUSIONS: Substituting OPV with IPV is not a cost-effective measure in Colombia, even if the cellular vaccine against whooping cough currently in use were replaced with an acellular vaccine combined with an IPV.

Vacunación antipoliomielítica en niños de la Ciudad de Buenos Aires / Antipoliomyelitic vaccination in children living in Buenos Aires City

A raíz de la presentación de un caso confirmado de poliomielitis paralítica por virus Sabin derivado (VSD) en niños de 15 meses se analizó la cobertura de vacunación antipoliomielítica en niños residentes en la Ciudad de Buenos Aires, durante el trienio 2006/2008. Se observó una mejora a lo largo del período analizado, pero sólo hubo valores superiores al 95 por ciento para la primera dosis. Aumentó la proporción de vacuna inactivada (IPV) en desmedro de la vacuna oral viva (OPV); en 2008, la cobertura con IPV primera dosis fue del 37,64 por ciento y del 19,48 por ciento para el ingreso escolar. La falta de inmunidad intestinal que se presenta en los niños vacunados con IPV, asociada a coberturas insatisfactorias condiciona un terreno propicio para la circulación de virus salvaje o VSD, lo cual favorece la aparición de casos de poliomielitis paralítica en niños no vacunados o inmunodeficientes.

Timing of Zero dose of OPV, first dose of hepatitis B and BCG vaccines.

The Indian Academy of Pediatrics has been recommending Hepatitis B vaccination for infants since 1992. This community based cross sectional study carried out in the rural and urban areas of Tamil Nadu found no significant rural urban difference in the proportions of children who had received BCG in 3 days/7 days and OPV-zero dose in 3 days/7 days after birth. The proportion of children who had received first dose of Hepatitis B in 3 days was significantly lower than those who had received BCG and OPV within 3 days after birth. The proportion of children who had received Hepatitis B on the day of birth was significantly lower in the rural area than in the urban area.

Deconstructing social resistance to pulse polio campaign in two north indian districts.

Objective: To gain an insight into the phenomenon of social resistance and rumors against pulse polio campaign. Design: Qualitative, community-based investigation, mapping perceptions of various stakeholders through in-depth interviews (IDIs), focus group discussions (FGDs), non-formal interactions and observations. Setting: Moradabad and JP Nagar districts of Uttar Pradesh. Subjects: IDIs (providers 33, mothers 33, community leaders 10); FGDs (providers 4, mothers 8) and non-formal interactions (156) with community leaders, parents, businessmen, journalists (Hindi and Urdu media), mobilizers, vaccinators and supervisors. Results: A distinct machination of social resistance and rumors against oral polio vaccine during supplementary immunization activities (SIA) was observed in some minority dominated areas. The pattern can be understood through a model that emerged through qualitative evidence. Inspite of all this, most parents in minority areas supported the SIAs. Only a few clusters from extremely marginalized sections continued to evade SIAs, with an endemic pattern. Through social osmosis, these rumors reached majority community as well and some parents were affected. However, in such cases, the resistance was sporadic and transient. Conclusion: While the program’s focus was on microbiological issues, the obstacles to polio eradication lie in the endemicity of social (and/or cultural) resistance in some pockets, leading to clustering of perpetually unimmunized children - inspite of good coverage of SIAs at macro level. This may sustain low levels of wild poliovirus transmission, and there can be exceptions to the robustness of the pulse approach. A micro level involvement of volunteers from marginalized pockets of minorities might be able to minimize or eliminate this resistance.

Pulse polio immunization in district Panipat: a process evaluation.

OBJECTIVE: To evaluate all steps of pulse polio immunization on special sub national immunization day. METHODS: On a sub-national immunization day (SNID), 120 booths were randomly selected from 662 booths by probability proportionate to size (PPS) sampling technique. RESULTS: It was observed that attendance in the district level meeting was thin (30%). 34% workers were doing this work for the first time without any training. 40% of the vaccinators were neither working according to micro plan nor were same as mentioned in the micro plan. Supervision too was found deficient. CONCLUSION: In a sustained and long drawn programme like IPPI, sustaining the interest and motivation of health personnel is paramount. This paper emphasises the importance of continued re-orientation training to keep them motivated and updated.

Molecular analysis and implications of neurovirulent circulating vaccine-derived poliovirus in Jamaica: a case report and review of literature / Análisis molecular e implicaciones del poliovirus derivado de las vacunas neurovirulentas circulantes (reporte de un caso y revisión de la literatura)

As the goal to eradicate wild polio virus (WPV) is approached, outbreaks associated with vaccine derived polioviruses (VDPV) with neurovirulent properties have emerged. The relevance for the spread of infection by nonparalytic cVDPV cases, with mutations associated with neurovirulence, is discussed with reference to the molecular analysis of a VDPV isolated from a Jamaican child who presented with aseptic meningitis. Potential risks to the Jamaican community resulting from circulation of cVDPV, and critical factors defined by the World Health Organization (WHO) in the global eradication of Polio are analyzed in the context of immunization coverage, and the need to stop all Oral Polio Vaccine (OPV) use once wild polioviruses (WPVs) have been eradicated.

A medida que nos hemos acercado a la meta de erradicar el virus de la polio salvaje (VPS), se han producido brotes asociados con los poliovirus derivados de la vacuna (VDPV) con propiedades neurovirulentas. El presente trabajo discute la importancia de estos en la diseminación de la infección por casos no paralíticos de cVDPV, en relación con el análisis molecular de un VDPV aislado a partir de un niño jamaicano que presentaba meningitis aséptica. Los riesgo potenciales para la comunidad jamaicana como resultado de la circulación de cVDPV, y los factores críticos definidos por la Organización de Mundial de la Salud (OMS) en la erradicación global de la polio, se analizan en el contexto de la cobertura de la inmunización, y la necesidad de detener todo uso de la Vacuna Oral de la Polio (VOP), una vez que los poliovirus salvajes (PVS) hayan sido erradicados.

Evaluation of intensive pulse polio immunization in District Valsad during 2007.

Three rounds of pulse polio immunization in January, February and March, 2007 were evaluated in Valsad and Vapi cities. Randomly selected team members of 50% booths and teams working during house to house activity were interviewed. Approximately 80% of eligible children were immunized on booths whereas remaining eligible were covered during house to house activity. In February, 2007 round, mOPV type 1 was first time introduced in Gujarat. Utilizers of booth services received information about these rounds mainly from television and miking. During house to house activity, few unimmunised children were found. Adequate manpower with proper training and community mobilization can improve the coverage.

Seroepidemiology of poliovirus antibody among the children in Eastern Turkey.

BACKGROUND & OBJECTIVE: Data on immunization are generally based on questionnaire methods or evaluation of health records in most of the developing countries like Turkey. Therefore, serological studies are useful to appraise the impact of vaccination programmes and to improve immunization policies. This serological study was undertaken to determine the immunity status of children to poliovirus in Eastern Turkey. METHODS: A cross-sectional and community-based field study was done with the sampling method of 30 clusters recommended for field studies. A total of 204 children aged 2-71 months were included. Complement fixation test was used to measure antibody titres to poliovirus serotypes. Subjects with serum antibody titres as 1:10 and lower were accepted as seronegative. A semi-structured questionnaire and official records of health care units were used to gather information about status of vaccination. RESULTS: Of the 204 children included, 54.4 per cent were boys and mean age was 31.5 +/- 19.8 months; 26.5 per cent of the children were seronegative. According to official records 64.7 per cent of subjects were full vaccinated. Sensitivity and specificity of official health records were 83.6 and 67.3 per cent in relation to immunity status of children, respectively. Regarding number of OPV doses given to children, the sensitivity and specificity of parents recall in relation to official records were 98.0 and 17.4 per cent, respectively. INTERPRETATION & CONCLUSION: Approximately, one of four children was determined to be seronegative. This high seronegativity brings risk to control of polio in Eastern Turkey which is at the post-elimination era since 1998. Additionally, parents recall did not provide reliable information to predict the immunity status and number of OPV doses given to children.