PREVALENCE OF NEUTRALIZING ANTIBODIES AGAINST POLIOVIRUS 1, 2, AND 3 IN HEALTHCARE PROFESSIONALS AGED 20-50 YEARS.

OBJECTIVE: To describe the prevalence of neutralizing antibodies against poliovirus (PV1, PV2, and PV3) in blood samples of healthcare professionals aged 20 to 50 years. METHODS: Health professionals who serve children at Darcy Vargas Children's Hospital and the Department of Pediatrics of Irmandade da Santa Casa de São Paulo. The sample size was calculated at 323 participants. The Mantel-Haenszel chi-square was used to verify differences between groups. The neutralization reaction detected human poliovirus antibodies. For susceptible individuals, vaccination with the inactivated+triple acellular polio vaccine was performed, and neutralizing antibodies were re-dosed after one week. RESULTS: 333 professionals were studied - 92.8% were immune to poliovirus 1, 86.5% to poliovirus 2, and 63.3% to poliovirus 3; 37% had titers less than 1:8 for any serotype, 5;1% had titers below 1:8 for all three. Vaccination with inactivated polio vaccine was performed for susceptible participants, and neutralizing antibodies were dosed after one week, showing increased titers for all polioviruses. CONCLUSIONS: Despite the detection of a significant percentage of individuals with low poliovirus antibody titer, the challenge with vaccination demonstrated immune response compatible with poliovirus immunity.

Prevalence of neutralizing antibodies against poliovirus 1, 2, and 3 in healthcare professionals aged 20-50 years / Prevalência de anticorpos neutralizantes contra poliovírus 1, 2 e 3 em profissionais de saúde de 20 a 50 anos de idade

ABSTRACT Objective: To describe the prevalence of neutralizing antibodies against poliovirus (PV1, PV2, and PV3) in blood samples of healthcare professionals aged 20 to 50 years. Methods: Health professionals who serve children at Darcy Vargas Children's Hospital and the Department of Pediatrics of Irmandade da Santa Casa de São Paulo. The sample size was calculated at 323 participants. The Mantel-Haenszel chi-square was used to verify differences between groups. The neutralization reaction detected human poliovirus antibodies. For susceptible individuals, vaccination with the inactivated+triple acellular polio vaccine was performed, and neutralizing antibodies were re-dosed after one week. Results: 333 professionals were studied - 92.8% were immune to poliovirus 1, 86.5% to poliovirus 2, and 63.3% to poliovirus 3; 37% had titers less than 1:8 for any serotype, 5;1% had titers below 1:8 for all three. Vaccination with inactivated polio vaccine was performed for susceptible participants, and neutralizing antibodies were dosed after one week, showing increased titers for all polioviruses. Conclusions: Despite the detection of a significant percentage of individuals with low poliovirus antibody titer, the challenge with vaccination demonstrated immune response compatible with poliovirus immunity.

RESUMO Objetivo: Descrever a prevalência de anticorpos neutralizantes contra poliovírus (tipos 1, 2 e 3) em amostra de sangue de profissionais de saúde com idade de 20 a 50 anos. Métodos: Profissionais de saúde que atendem crianças do Hospital Infantil Darcy Vargas e do Departamento de Pediatria da Irmandade da Santa Casa de São Paulo. O tamanho da amostra foi de 323 participantes. Os anticorpos contra poliovírus humanos foram detectados pela reação de neutralização. Para os indivíduos suscetíveis, foram administradas vacina para poliomielite inativada+tríplice e nova dosagem de anticorpos neutralizantes após uma semana. Utilizou-se o teste do qui-quadrado de Mantel-Haenszel para verificar as diferenças entre os grupos. Resultados: Foram estudados 333 profissionais - 92,8% eram imunes ao poliovírus 1; 86,5%, ao poliovírus 2; 63,57%, ao poliovírus 3; 37% apresentaram títulos inferiores a 1:8 para qualquer sorotipo; 5,1% tinham títulos abaixo de 1:8 para os três. Após a vacinação dos suscetíveis, houve elevação dos títulos para todos os poliovírus. Conclusões: Apesar da detecção de percentual significativo de indivíduos com baixo título de anticorpos para poliovírus, o desafio da vacinação demonstrou resposta imune robusta compatível.

Humoral and intestinal immunity induced by new schedules of bivalent oral poliovirus vaccine and one or two doses of inactivated poliovirus vaccine in Latin American infants: an open-label randomised controlled trial.

BACKGROUND: Replacement of the trivalent oral poliovirus vaccine (tOPV) with bivalent types 1 and 3 oral poliovirus vaccine (bOPV) and global introduction of inactivated poliovirus vaccine (IPV) are major steps in the polio endgame strategy. In this study, we assessed humoral and intestinal immunity in Latin American infants after three doses of bOPV combined with zero, one, or two doses of IPV. METHODS: This open-label randomised controlled multicentre trial was part of a larger study. 6-week-old full-term infants due for their first polio vaccinations, who were healthy on physical examination, with no obvious medical conditions and no known chronic medical disorders, were enrolled from four investigational sites in Colombia, Dominican Republic, Guatemala, and Panama. The infants were randomly assigned by permuted block randomisation (through the use of a computer-generated list, block size 36) to nine groups, of which five will be discussed in this report. These five groups were randomly assigned 1:1:1:1 to four permutations of schedule: groups 1 and 2 (control groups) received bOPV at 6, 10, and 14 weeks; group 3 (also a control group, which did not count as a permutation) received tOPV at 6, 10, and 14 weeks; group 4 received bOPV plus one dose of IPV at 14 weeks; and group 5 received bOPV plus two doses of IPV at 14 and 36 weeks. Infants in all groups were challenged with monovalent type 2 vaccine (mOPV2) at 18 weeks (groups 1, 3, and 4) or 40 weeks (groups 2 and 5). The primary objective was to assess the superiority of bOPV-IPV schedules over bOPV alone, as assessed by the primary endpoints of humoral immunity (neutralising antibodies-ie, seroconversion) to all three serotypes and intestinal immunity (faecal viral shedding post-challenge) to serotype 2, analysed in the per-protocol population. Serious and medically important adverse events were monitored for up to 6 months after the study vaccination. This study is registered with ClinicalTrials.gov, number NCT01831050, and has been completed. FINDINGS: Between May 20, 2013, and Aug 15, 2013, 940 eligible infants were enrolled and randomly assigned to the five treatment groups (210 to group 1, 210 to group 2, 100 to group 3, 210 to group 4, and 210 to group 5). One infant in group 1 was not vaccinated because their parents withdrew consent after enrolment and randomisation, so 939 infants actually received the vaccinations. Three doses of bOPV or tOPV elicited type 1 and 3 seroconversion rates of at least 97·7%. Type 2 seroconversion occurred in 19 of 198 infants (9·6%, 95% CI 6·2-14·5) in the bOPV-only groups, 86 of 88 (97·7%, 92·1-99·4) in the tOPV-only group (p<0·0001 vs bOPV-only), and 156 of 194 (80·4%, 74·3-85·4) infants in the bOPV-one dose of IPV group (p<0·0001 vs bOPV-only). A further 20 of 193 (10%) infants in the latter group seroconverted 1 week after mOPV2 challenge, resulting in around 98% of infants being seropositive against type 2. After a bOPV-two IPV schedule, all 193 infants (100%, 98·0-100; p<0·0001 vs bOPV-only) seroconverted to type 2. IPV induced small but significant decreases in a composite serotype 2 viral shedding index after mOPV2 challenge. 21 serious adverse events were reported in 20 patients during the study, including two that were judged to be possibly related to the vaccines. Most of the serious adverse events (18 [86%] of 21) and 24 (80%) of the 30 important medical events reported were infections and infestations. No deaths occurred during the study. INTERPRETATION: bOPV provided humoral protection similar to tOPV against polio serotypes 1 and 3. After one or two IPV doses in addition to bOPV, 80% and 100% of infants seroconverted, respectively, and the vaccination induced a degree of intestinal immunity against type 2 poliovirus. FUNDING: Bill & Melinda Gates Foundation.

Reactogenicity and immunogenicity of inactivated poliovirus vaccine produced from Sabin strains: a phase I Trial in healthy adults in Cuba.

BACKGROUND: To ensure that developing countries have the option to produce inactivated poliovirus vaccine (IPV), the Global Polio Eradication Initiative has promoted the development of an IPV using Sabin poliovirus strains (Sabin IPV). This trial assessed the reactogenicity and immunogenicity of Sabin IPV and adjuvanted Sabin IPV in healthy adults in Cuba. METHODS: This is a randomized, controlled phase I trial, enrolling 60 healthy (previously vaccinated) male human volunteers, aged 19-23 years to receive one dose of either Sabin IPV (20:32:64 DU/dose), adjuvanted Sabin IPV (10:16:32 DU/dose), or conventional Salk IPV (40:8:32 DU/dose). The primary endpoint for reactogenicity relied on monitoring of adverse events. The secondary endpoint measured boosting immune responses (i.e. seroconversion or 4-fold rise) of poliovirus antibody, assessed by neutralization assays. RESULTS: Sixty subjects fulfilled the study requirements. No serious adverse events reported were attributed to trial interventions during the 6-month follow-up period. Twenty-eight days after vaccination, boosting immune responses against poliovirus types 1-3 were between 90% and 100% in all vaccination groups. There was a more than 6-fold increase in median antibody titers between pre- and post-vaccination titers in all vaccination groups. DISCUSSION: Both Sabin IPV and adjuvanted Sabin IPV were well tolerated and immunogenic against all poliovirus serotypes. This result suggests that the aluminum adjuvant may allow a 50% (or higher) dose reduction.

Reactogenicidad asociada a la administración intradérmica de la vacuna de polio inactivada con un inyector sin aguja / Reactogenicity associated to the intradermally administered inactivated poliovirus vaccine with a needle-free injector

INTRODUCCIÓN: en la medida en que la meta de la erradicación de la poliomielitis llega a su concreción, la necesidad de contar con una vacuna de polio inactivada asequible y apropiada para el uso en países en vías de desarrollo se ha convertido en una meta para la Organización Mundial de la Salud. OBJETIVO: la evaluación de la reactogenicidad de la vacuna de polio inactivada. MÉTODOS: se realizó un estudio multicéntrico con diseño experimental, correspondiente a Fase I-II de un ensayo clínico controlado, aleatorio y a simple ciegas, en 471 lactantes sanos de ambos sexos nacidos entre los meses de julio y agosto de 2006 en Camagüey, cuyos padres brindaron su consentimiento por escrito y que cumplieron con los criterios de inclusión establecidos. Los niños recibieron a las 6, 10 y 14 semanas del nacimiento, tres dosis de vacuna de polio inactivada del Instituto de Sueros de Dinamarca, autorizada para su uso en esta investigación por las autoridades regulatorias nacionales. Al grupo de estudio A, se le administró por la vía intradérmica la dosis reducida de 0,1 mL de vacuna de polio inactivada en la cara anterolateral del muslo izquierdo utilizando el inyector sin aguja Biojector® 2000. El grupo control B recibió la dosis usual de 0,5 mL por la vía intramuscular profunda, administrada en el mismo sitio descrito antes con una jeringuilla prellenada. Se observaron los eventos adversos durante la primera hora, 24, 48, y 72 h subsiguientes, así como a los 7 y 30 d de administrada la vacuna. La reactogenicidad se evaluó inicialmente por el pediatra del área y luego por el médico de familia mediante la observación de los eventos adversos. RESULTADOS: 79,6 por ciento del total de niños asignados al grupo A y 75 por ciento del grupo B finalizaron el protocolo de investigación. No se detectaron eventos adversos moderados o serios. Predominaron las reacciones adversas locales menores, sobre todo induración, dolor y enrojecimiento en el sitio de la inyección. CONCLUSIÓN:...(AU)

INTRODUCTION: as the goal of poliomyelitis eradication is about to be accomplished, the need for an affordable and appropriate inactivated poliovirus vaccine (IPV) for use in developing countries has become a target for WHO. OBJECTIVE: to evaluate the reactogenicity of the inactivated poliovirus vaccine. METHOD: an experimental-type multicenter study was conducted, as part of a Phase I-II controlled clinical randomized and blinded assay, in 471 healthy infants of both sexes born in July and August 2006 in Camag³ey province. The parents of the children who met the inclusion criteria gave their consent in writing. The children received three doses of the inactivated poliovirus vaccine at 6, 10 and 14 weeks after birth. This vaccine came form the Institute of Sera in Denmark and had been approved for use in this assay by the Cuban regularoty authorities, Low 0.1 ml inactivated poliovirus vaccine dose was intradermally administered to the study group A in the anterolateral side of the left thigh using the needle-free injector called Biojector ® 2000. The usual 0.5 mL dose was intramuscularly administered on the same site using a pre-filled syringe. The adverse events were observed during the first hour, 24, 48, and 72 hours after the immunization, as well as 7 and 30 days afterwards. The pediatrician in charge of the health area evaluated the reactogenicity at first and then the family physician was in charge of observing the adverse events in the remaining period. RESULTS: the 79.6 percent of children in group A and 75 percent in group B completed the research protocol. Mild local adverse reactions prevailed, mainly induration, pain and redness at the injection site. CONCLUSION: the clinical trial proved the safety of the inactivated poliovirus vaccine for intramuscular administration, and also showed the safety of the intradermal route of administration and of the needle-free injector(AU)

Effect on seroprevalence of anti-poliovirus antibodies and on vaccination coverage of the implementation of a DTwP-IPV-Hib vaccination programme in a South American city.

Vaccination coverage and seroprevalence of poliovirus antibodies were assessed in Argentinean children (aged 8-12 and 19-21 months) living in Cordoba City pre-/post-implementation of a DTwP-IPV-Hib vaccination programme, and compared to those of controls from neighbouring populations receiving a full oral poliovirus vaccine schedule. Vaccination coverage was higher in control areas pre-intervention; this increased post-intervention in Cordoba (>90%) but not in control areas. Poliovirus types 1 and 2 seroprotection rates were >97% in all groups pre-/post-intervention. Type 3 seroprotection rates were generally lower, but increased post-intervention in Cordoba becoming significantly higher than control rates. Anti-type 1 and 3 antibody titres increased twofold and sevenfold, respectively, post-intervention, whereas anti-type 2 antibody titres decreased ~40% in the 8-12 months group. All titres increased in the 19-21 months post-intervention group. The introduction of a three-dose primary DTwP-IPV-Hib schedule maintained protection against poliovirus types 1 and 2, and increased protection against type 3, while vaccine coverage in the study area increased.

Universal use of inactivated polio vaccine.

OBJECTIVES: To present an update on the status of poliomyelitis worldwide, number of cases per year, regions most affected by the disease, vaccines currently available, their risks and benefits, monovalent vaccine use, risks of disseminating a mutant virus in the community, progress that has been made in terms of worldwide eradication and the World Health Organization's (WHO) proposals in this transition period between global eradication and the post-eradication period. SOURCES OF DATA: Data for the period from 1955 to 2005 were searched in MEDLINE, LILACS, The Web, Doctor's Guide, WHO website and the Pan American Health Organization (PAHO) website and text book. SUMMARY OF THE FINDINGS: In 1988, the WHO established the goal of eradicating the disease and interrupting transmission of the wild virus globally. Since then, there has been a dramatic decline of the disease, although in 2005 there were still some countries considered endemic and others where polio returned on account of imported viruses. The vaccines used worldwide are the classical tOPV and IPV, and in this eradication process, the use of mOPV vaccines has been encouraged in places where only one type of poliovirus circulates. In addition to spreading the virus in the community, the OPV vaccines may, however, cause paralyses by reversal of the neurovirulence process. CONCLUSIONS: For a world free of poliomyelitis disease, it would be necessary to interrupt circulation of the virus, which will only be possible if the OPV virus were to be discontinued, in accordance with the WHO proposals for this transition period and the post-eradication period.

Early immunization with inactivated poliovirus vaccine in premature infants.

The antibody titers of 41 premature infants receiving inactivated poliovirus vaccine at 2 months of age (control group) were compared with titers of 39 infants receiving an additional dose at 5 to 10 days of age (study group). At 1 month of age 97.4% of the study group but only 70.8% of the control group had protective antibodies against poliovirus 3 (p < 0.001).

Epidemiological surveillance and control of poliomyelitis in the Republic of Cuba.

Organization and performance of Poliomyelitis Epidemiological Surveillance and control in Cuba are described. Since the first vaccination campaign the average of vaccinated population is of 90% and over. Annual and cyclic epidemic peaks disappeared after oral polio vaccination. During 20 years only 7 sporadic cases were diagnosed; the last one in 1979. Surveillance of disease and immunity of infant population was carried out by clinical examination, isolation techniques for Polio and other enteroviruses and by testing neutralizing antibodies in 0-4 years of age population samples from 1963 to 1979. Satisfactory high antibody levels have been maintained up to date after using different combinations of Polio viruses in vaccines and by having regulated the dose intervals. Subsequent virologic investigation in children under age 3, from nurseries of several provincial capitals, leads us to think that there is no Poliovirus circulation in the country. Behavior of the disease and the laboratory finding indicators reveal very successful results in Poliomyelitis elimination programmes.