Recommendations for modernizing infant vaccination schedules with combination vaccines in Colombia and Peru.

The objective of this article was to consider the vaccination challenges in Colombia and Peru and the role of pediatric combination vaccines in overcoming these challenges. Barriers to including new vaccines with more antigens remain apparent in parts of these countries, where vaccine-preventable diseases in infants continue to be a major problem. The challenges include the heterogeneity of vaccine coverage within each country and in neighboring countries, which can contribute to poor rates of vaccination coverage; the adverse impact of the inward migration of unvaccinated individuals, which has favored the re-emergence of vaccine-preventable diseases; vaccine shortages; and the impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and the associated shifts in health care resources. To improve the coverage of pediatric vaccines in Colombia and Peru, it will be necessary to ensure the widespread integration into vaccine schedules of combination vaccines containing diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b and hepatitis B antigens with a three-dose primary series delivered at 2, 4 and 6 months of age followed by a booster at 18 months of age. Such vaccines play important roles in preventing diphtheria, tetanus and pertussis; eradicating polio; and providing boosting against H. influenzae type b.

El objetivo de este artículo es considerar los desafíos que se enfrentan en Colombia y Perú con respecto a la vacunación y el papel de las vacunas combinadas pediátricas para superar estos desafíos. Los obstáculos para incluir vacunas nuevas con más antígenos siguen siendo evidentes en algunos lugares de estos países, donde las enfermedades prevenibles por vacunación en menores de 1 año continúan siendo un grave problema. Entre los desafíos se incluye la heterogeneidad de la cobertura de vacunación en cada país y en los países vecinos, lo que puede contribuir con que se registren tasas bajas de cobertura de vacunación; el impacto adverso de la migración interna de personas no vacunadas, lo que ha favorecido la reaparición de enfermedades prevenibles por vacunación; la escasez de vacunas, y el impacto de la pandemia del coronavirus de tipo 2 causante del síndrome respiratorio agudo grave (SARS-CoV-2) y los consiguientes cambios en los recursos de atención médica. Para mejorar la cobertura de las vacunas pediátricas en Colombia y Perú será necesario integrar de manera generalizada en los calendarios de vacunación vacunas combinadas con antígenos de difteria, tétanos, tos ferina acelular, poliovirus inactivados, Haemophilus influenzae tipo b y hepatitis B con una serie primaria de tres dosis administradas a los 2, 4 y 6 meses de edad, seguida de un refuerzo a los 18 meses de edad. Esas vacunas desempeñan un papel esencial en la prevención de la difteria, el tétanos y la tos ferina; la erradicación de la polio; y el refuerzo contra H. influenzae tipo b.

O objetivo deste artigo foi avaliar os desafios da vacinação na Colômbia e no Peru e o papel das vacinas pediátricas combinadas na superação de tais desafios. Os obstáculos para incluir novas vacinas com mais antígenos permanecem visíveis em partes desses países, onde doenças imunopreveníveis em lactentes continuam a ser um grande problema. Os desafios incluem a heterogeneidade da cobertura vacinal dentro de cada país e nos países vizinhos, o que pode contribuir para baixas taxas de cobertura vacinal; o impacto adverso da migração interna de pessoas não vacinadas, o que favoreceu o ressurgimento de doenças imunopreveníveis; a escassez de vacinas; e o impacto da pandemia de síndrome respiratória aguda grave do coronavírus 2 (SARS-CoV-2) e mudanças relacionadas nos recursos de atenção à saúde. Para melhorar a cobertura das vacinas pediátricas na Colômbia e no Peru, será necessário assegurar sua integração generalizada em esquemas de vacinas combinadas contendo antígenos de difteria, tétano, pertussis acelular, poliovírus inativado, Haemophilus influenzae tipo B e hepatite B, com uma série primária de três doses aplicadas aos 2, 4 e 6 meses de idade seguidas de um reforço aos 18 meses de idade. Tais vacinas desempenham papéis importantes na prevenção da difteria, tétano e coqueluche; na erradicação da poliomielite; e no reforço contra H. influenzae tipo b.

Preparation and evaluation of formalized bivalent Newcastle and Salmonella poultry vaccine

This study was conducted to prepare and evaluate the potency of different inactivated vaccine formulations that protect chickens against Salmonella Enteritidis and Newcastle disease virus using Montanide as adjuvant. Protection and the humoral immune response of prepared vaccines against Salmonella Enteritidis and Newcastle disease virus was evaluated and compared to imported vaccine. In this study, different formulae of Salmonella Enteritidis and Newcastle disease vaccines were prepared and compared with the imported one by measuring the antibody titer against Newcastle disease virus by hemagglutination inhibition test and the antibody titer against Salmonella Enteritidis using Enzyme Linked Immunosorbent Assay. On the other hand, the protection percentages against Newcastle disease and Salmonella Enteritidis were recorded to determine the best effective formula. The highest hemagglutination inhibition antibody level against NDV at first week was recorded for the prepared combined Newcastle disease and Salmonella Enteritidis vaccine (4.2 log2) followed by the prepared monovalent Newcastle disease (3.4 log2); the lowest antibody level (3.1 log2) was obtained with the imported vaccine. A gradual increase was observed in all groups to 7.1 log2, 6.8 log2 and 6.4 log2 at fourth week post vaccination, respectively. The antibody titer against Salmonella Enteritidis was 552 for the prepared combined Salmonella Enteritidis and Newcastle disease, followed by the prepared monovalent Salmonella Enteritidis (477) at first week post vaccination; the antibody titer obtained for the imported vaccine was 477. There was a gradual increase to 1456, 1406 and 1130 at fourth week post vaccination, respectively. Prepared combined vaccines gave the highest protection percentage, followed by prepared monovalent types and finally imported vaccines. Vaccination by the prepared combined Salmonella Enteritidis and Newcastle disease vaccine may be a way to increase the resistance of birds to Salmonella and Newcastle and to decrease the shedding rate(AU)

Este estudio se llevó a cabo para preparar y evaluar la potencia de diferentes formulaciones de vacunas inactivadas que protegen a los pollos contra Salmonella Enteritidis y el virus de la enfermedad de Newcastle utilizando Montanide como adyuvante. Se evaluó la protección y la respuesta inmune humoral de las vacunas preparadas contra Salmonella Enteritidis y el virus de la enfermedad de Newcastle y se comparó con la vacuna importada. En este estudio se prepararon diferentes fórmulas de vacunas contra Salmonella Enteritidis y la enfermedad de Newcastle y se compararon con la importada midiendo el título de anticuerpos contra el virus de la enfermedad de Newcastle mediante la prueba de inhibición de la hemaglutinación y el título de anticuerpos contra Salmonella Enteritidis mediante ELISA. Por otra parte, se registraron los porcentajes de protección contra la enfermedad de Newcastle y Salmonella Enteritidis para determinar la fórmula más eficaz. El mayor nivel de anticuerpos inhibidores de la hemaglutinación contra el virus de la enfermedad de Newcastle, en la primera semana, se registró con la vacuna combinada preparada contra la enfermedad de Newcastle y Salmonella Enteritidis (4,2 log2), seguida de la vacuna monovalente preparada contra la enfermedad de Newcastle (3,4 log2); el menor nivel de anticuerpos (3,1 log2) se obtuvo con la vacuna importada. Se observó un aumento gradual en todos los grupos hasta alcanzar 7,1 log2, 6,8 log2 y 6,4 log2 en la cuarta semana tras la vacunación, respectivamente. El título de anticuerpos contra Salmonella Enteritidis fue de 552 para la vacuna combinada preparada contra la Salmonella Enteritidis y enfermedad de Newcastle, seguida por la vacuna monovalente preparada contra Salmonella Enteritidis (477) en la primera semana después de la vacunación; el título de anticuerpos obtenido con la vacuna importada fue de 477. Hubo un aumento gradual hasta 1456, 1406 y 1130 en la cuarta semana después de la vacunación, respectivamente. Las vacunas combinadas preparadas dieron el mayor porcentaje de protección, seguidas por los tipos monovalentes preparados y, por último, por las vacunas importadas. La vacunación con la vacuna combinada preparada contra la Salmonella Enteritidis y la enfermedad de Newcastle puede ser una forma de aumentar la resistencia de las aves a la Salmonella y Newcastle y de disminuir la tasa de excreción(AU)

Recommendations for modernizing infant vaccination schedules with combination vaccines in Colombia and Peru / Recomendaciones para modernizar los calendarios de vacunación infantil con vacunas combinadas en Colombia y Perú / Recomendações para modernizar os esquemas de vacinação infantil com vacinas combinadas na Colômbia e no Peru

ABSTRACT The objective of this article was to consider the vaccination challenges in Colombia and Peru and the role of pediatric combination vaccines in overcoming these challenges. Barriers to including new vaccines with more antigens remain apparent in parts of these countries, where vaccine-preventable diseases in infants continue to be a major problem. The challenges include the heterogeneity of vaccine coverage within each country and in neighboring countries, which can contribute to poor rates of vaccination coverage; the adverse impact of the inward migration of unvaccinated individuals, which has favored the re-emergence of vaccine-preventable diseases; vaccine shortages; and the impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and the associated shifts in health care resources. To improve the coverage of pediatric vaccines in Colombia and Peru, it will be necessary to ensure the widespread integration into vaccine schedules of combination vaccines containing diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b and hepatitis B antigens with a three-dose primary series delivered at 2, 4 and 6 months of age followed by a booster at 18 months of age. Such vaccines play important roles in preventing diphtheria, tetanus and pertussis; eradicating polio; and providing boosting against H. influenzae type b.

RESUMEN El objetivo de este artículo es considerar los desafíos que se enfrentan en Colombia y Perú con respecto a la vacunación y el papel de las vacunas combinadas pediátricas para superar estos desafíos. Los obstáculos para incluir vacunas nuevas con más antígenos siguen siendo evidentes en algunos lugares de estos países, donde las enfermedades prevenibles por vacunación en menores de 1 año continúan siendo un grave problema. Entre los desafíos se incluye la heterogeneidad de la cobertura de vacunación en cada país y en los países vecinos, lo que puede contribuir con que se registren tasas bajas de cobertura de vacunación; el impacto adverso de la migración interna de personas no vacunadas, lo que ha favorecido la reaparición de enfermedades prevenibles por vacunación; la escasez de vacunas, y el impacto de la pandemia del coronavirus de tipo 2 causante del síndrome respiratorio agudo grave (SARS-CoV-2) y los consiguientes cambios en los recursos de atención médica. Para mejorar la cobertura de las vacunas pediátricas en Colombia y Perú será necesario integrar de manera generalizada en los calendarios de vacunación vacunas combinadas con antígenos de difteria, tétanos, tos ferina acelular, poliovirus inactivados, Haemophilus influenzae tipo b y hepatitis B con una serie primaria de tres dosis administradas a los 2, 4 y 6 meses de edad, seguida de un refuerzo a los 18 meses de edad. Esas vacunas desempeñan un papel esencial en la prevención de la difteria, el tétanos y la tos ferina; la erradicación de la polio; y el refuerzo contra H. influenzae tipo b.

RESUMO O objetivo deste artigo foi avaliar os desafios da vacinação na Colômbia e no Peru e o papel das vacinas pediátricas combinadas na superação de tais desafios. Os obstáculos para incluir novas vacinas com mais antígenos permanecem visíveis em partes desses países, onde doenças imunopreveníveis em lactentes continuam a ser um grande problema. Os desafios incluem a heterogeneidade da cobertura vacinal dentro de cada país e nos países vizinhos, o que pode contribuir para baixas taxas de cobertura vacinal; o impacto adverso da migração interna de pessoas não vacinadas, o que favoreceu o ressurgimento de doenças imunopreveníveis; a escassez de vacinas; e o impacto da pandemia de síndrome respiratória aguda grave do coronavírus 2 (SARS-CoV-2) e mudanças relacionadas nos recursos de atenção à saúde. Para melhorar a cobertura das vacinas pediátricas na Colômbia e no Peru, será necessário assegurar sua integração generalizada em esquemas de vacinas combinadas contendo antígenos de difteria, tétano, pertussis acelular, poliovírus inativado, Haemophilus influenzae tipo B e hepatite B, com uma série primária de três doses aplicadas aos 2, 4 e 6 meses de idade seguidas de um reforço aos 18 meses de idade. Tais vacinas desempenham papéis importantes na prevenção da difteria, tétano e coqueluche; na erradicação da poliomielite; e no reforço contra H. influenzae tipo b.

Dual-Use Vaccine for Diarrhoeal Diseases: Cross-Protective Immunogenicity of a Cold-Chain-Free, Live-Attenuated, Oral Cholera Vaccine against Enterotoxigenic Escherichia coli (ETEC) Challenge in BALB/c Mice.

In low- and middle-income countries, diarrhoeal diseases are the second most common cause of mortality in children, mainly caused by enterotoxin-producing bacteria, such as Shigella, Vibrio, Salmonella, and Escherichia coli. Cholera and traveller's diarrhoea are caused by Vibrio cholerae (O1 and O139 serogroups) and enterotoxigenic Escherichia coli (ETEC), respectively. The cholera toxin (CT) produced by V. cholerae and the heat-labile enterotoxin (LT) of ETEC are closely related by structure, function, and the immunological response to them. There is no exclusive vaccine for ETEC; however, cholera vaccines based on the CT-B component elicit a short-term cross-protection against ETEC infection. In this context, the cross-protective efficacy of MyCholTM, a prototype cold-chain-free, live-attenuated, oral cholera vaccine against V. cholerae O139 was evaluated in BALB/c mice. The 100% lethal dose (LD100) of 109 CFU/mL of the ETEC H10407 strain was used for the challenge studies. The mice immunised with MyChol™ survived the challenge by producing anti-CT antibodies, which cross-neutralised the LT toxin with no body weight loss and no sign of diarrhoea. Compared to unimmunised mice, the immunised mice elicited the neutralising antitoxin that markedly decreased ETEC colonisation and fluid accumulation caused by ETEC H10407 in the intestines. The immunised mice recorded higher antibody titres, including anti-CT IgG, anti-LT IgG, anti-CT-B IgG, and anti-LTB IgG. Only a two-fold rise in anti-CT/CT-B/LT/LT-B IgA was recorded in serum samples from immunised mice. No bactericidal antibodies against ETEC H10407 were detected. This investigation demonstrates the safety, immunogenicity, and cross-protective efficacy of MyCholTM against the ETEC H10407 challenge in BALB/c mice.

Adjuvant effect of mesoporous silica SBA-15 on anti-diphtheria and anti-tetanus humoral immune response.

Routine immunization against diphtheria and tetanus has drastically reduced the incidence of these diseases worldwide. Anti-diphtheria/tetanus vaccine has in general aluminum salt as adjuvant in its formulation that can produce several adverse effects. There is a growing interest in developing new adjuvants. In this study, we evaluated the efficiency of SBA-15 as an adjuvant in subcutaneous immunization in mice with diphtheria (dANA) and tetanus (tANA) anatoxins as well as with the mixture of them (dtANA). The tANA molecules and their encapsulation in SBA-15 were characterized using Small-Angle X-ray Scattering (SAXS), Dynamical Light Scattering (DLS), Nitrogen Adsorption Isotherm (NAI), Conventional Circular Dichroism (CD)/Synchrotron Radiation Circular Dichroism (SRCD) Spectroscopy, and Tryptophan Fluorescence Spectroscopy (FS). The primary and secondary antibody response elicited by subcutaneous immunization of High (HIII) and Low (LIII) antibody responder mice with dANA, tANA, or dtANA encapsulated in the SBA-15 were determined. We demonstrated that SBA-15 increases the immunogenicity of dANA and tANA antigens, especially when administered in combination. We also verified that SBA-15 modulates the antibody response of LIII mice, turning them into high antibody responder. Thus, these results suggest that SBA-15 may be an effective adjuvant for different vaccine formulations.

Atraso na vacina tetravalente (DTP+Hib) em crianças de 12 a 23 meses de idade: Pesquisa Nacional de Saúde, 2013 / Delay in quadrivalent vaccine (DTP+Hib) in children 12 to 23 months of age: Brazilian National Health Survey, 2013 / Retraso en la vacuna tetravalente (DTP+Hib) en niños de 12 a 23 meses de edad: Encuesta Nacional de Salud, 2013

Resumo: O objetivo foi estimar a prevalência do atraso nas três doses da vacina tetravalente (DTP+Hib) em crianças de 12 a 23 meses de idade, no Brasil, por meio dos dados da Pesquisa Nacional de Saúde (PNS) de 2013 e descrever o atraso em cada uma das doses segundo variáveis sociodemográficas, utilização de serviços e intervenções públicas de saúde. Foram utilizados dados da PNS, estudo transversal realizado em 2013. O desfecho foi o atraso pelo menos em uma das três doses da vacina tetravalente. Considerou-se como atraso a dose recebida pelo menos 30 dias após a data preconizada, segundo informação da caderneta de vacinação. A prevalência do atraso foi descrita segundo variáveis sociodemográficas e utilização de serviços de saúde. Realizou-se análise descritiva obtendo-se frequências absolutas e relativas e seus respectivos intervalos de 95% de confiança. Das 2.016 crianças com informações coletadas, 1.843 foram analisadas. A prevalência de atraso de pelo menos uma dose da vacina foi de 44%. Observou-se atraso de 14,8% na primeira, 28,8% na segunda e 45,4% na terceira dose, sendo que 10% das crianças tiveram atraso nas três doses. Maiores prevalências de atraso foram encontradas em crianças do sexo masculino, de cor da pele parda, pertencentes ao quintil mais pobre de riqueza, moradores da zona rural e da Região Norte do Brasil. Evidenciou-se alta prevalência de atraso na vacina tetravalente (DTP+Hib) em crianças de 12 a 23 meses do Brasil, sendo maior na terceira dose.

Abstract: The study aimed to estimate the prevalence of delay in the three doses of quadrivalent vaccine (DTP+Hib) in children 12 to 23 months of age in Brazil, based on data from the Brazilian National Health Survey (PNS) of 2013 and to analyze the delay in each of the doses according to sociodemographic variables and use of health services and public health interventions. The data are from the PNS a cross-sectional study performed in 2013. The outcome was delay in at least one of the three doses of the quadrivalent vaccine. Delay was defined as a dose received at least 30 days after the recommended date according to information on the child's vaccination card. Prevalence of delay was analyzed according to sociodemographic variables and use of health services. A descriptive analysis was performed to obtain absolute and relative frequencies and their respective 95% confidence intervals. Of the 2,016 children with information collected, 1,843 were analyzed. The prevalence of delay in at least one dose of the vaccine was 44%. There was a delay of 14.8% in the first dose, 28.8% in the second, and 45.4% in the third, and 10% of the children had delays in all three doses. Higher prevalence of delay was associated with male gender, brown skin color, the poorest income quintile, and residence in rural areas and the North of Brazil. The study revealed high prevalence of delay with the quadrivalent vaccine (DTP+Hib) in children 12 to 23 months of age in Brazil, with the highest delay in the third dose.

Resumen: El objetivo fue estimar la prevalencia del atraso en las tres dosis de la vacuna tetravalente (DTP+Hib) en niños de 12 a 23 meses de edad, en Brasil, mediante los datos de la Encuesta Nacional de Salud (PNS) de 2013 y describir el retraso en cada una de las dosis, según variables sociodemográficas, utilización de servicios e intervenciones públicas de salud. Se trata de un estudio transversal, realizado en 2013, con datos de la PNS. El resultado fue el retraso por lo menos en una de las tres dosis de la vacuna tetravalente. Se consideró como un atraso la dosis recibida por lo menos 30 días tras la fecha prefijada, según la información de la cartilla de vacunación. La prevalencia del atraso fue descrita según variables sociodemográficas y utilización de servicios de salud. Se realizó un análisis descriptivo, obteniéndose frecuencias absolutas y relativas, así como sus respectivos intervalos de 95% de confianza. De los 2016 niños con información recogida, se analizaron 1843. La prevalencia de atraso de por lo menos una dosis de la vacuna fue de un 44%. Se observó un retraso de 14,8% en la primera, un 28,8% en la segunda y un 45,4% en la tercera dosis, siendo que un 10% de los niños sufrieron atraso en las tres dosis. Las mayores prevalencias de atraso se encontraron en niños de sexo masculino, mestizos, pertenecientes al quintil más pobre de riqueza, habitantes de la zona rural y de la Región Norte de Brasil. Se evidenció una alta prevalencia de atraso en la vacuna tetravalente (DTP+Hib) en niños de 12 a 23 meses de Brasil, siendo mayor en la tercera dosis.

Adjuvant effect of mesoporous silica SBA-15 on anti-diphtheria and anti-tetanus humoral immune response

Routine immunization against diphtheria and tetanus has drastically reduced the incidence of these diseases worldwide. Anti-diphtheria/tetanus vaccine has in general aluminum salt as adjuvant in its formulation that can produce several adverse effects. There is a growing interest in developing new adjuvants. In this study, we evaluated the efficiency of SBA-15 as an adjuvant in subcutaneous immunization in mice with diphtheria (dANA) and tetanus (tANA) anatoxins as well as with the mixture of them (dtANA). The tANA molecules and their encapsulation in SBA-15 were characterized using Small-Angle X-ray Scattering (SAXS), Dynamical Light Scattering (DLS), Nitrogen Adsorption Isotherm (NAI), Conventional Circular Dichroism (CD)/Synchrotron Radiation Circular Dichroism (SRCD) Spectroscopy, and Tryptophan Fluorescence Spectroscopy (FS). The primary and secondary antibody response elicited by subcutaneous immunization of High (HIII) and Low (LIII) antibody responder mice with dANA, tANA, or dtANA encapsulated in the SBA-15 were determined. We demonstrated that SBA-15 increases the immunogenicity of dANA and tANA antigens, especially when administered in combination. We also verified that SBA-15 modulates the antibody response of LIII mice, turning them into high antibody responder. Thus, these results suggest that SBA-15 may be an effective adjuvant for different vaccine formulations.

Enhancement of the HIV-1-Specific Immune Response Induced by an mRNA Vaccine through Boosting with a Poxvirus MVA Vector Expressing the Same Antigen.

Development of a vaccine against HIV remains a major target goal in the field. The recent success of mRNA vaccines against the coronavirus SARS-CoV-2 is pointing out a new era of vaccine designs against pathogens. Here, we have generated two types of mRNA vaccine candidates against HIV-1; one based on unmodified vectors and the other on 1-methyl-3'-pseudouridylyl modified vectors expressing a T cell multiepitopic construct including protective conserved epitopes from HIV-1 Gag, Pol and Nef proteins (referred to as RNA-TMEP and RNA-TMEPmod, respectively) and defined their biological and immunological properties in cultured cells and in mice. In cultured cells, both mRNA vectors expressed the corresponding protein, with higher levels observed in the unmodified mRNA, leading to activated macrophages with differential induction of innate immune molecules. In mice, intranodal administration of the mRNAs induced the activation of specific T cell (CD4 and CD8) responses, and the levels were markedly enhanced after a booster immunization with the poxvirus vector MVA-TMEP expressing the same antigen. This immune activation was maintained even three months later. These findings revealed a potent combined immunization regimen able to enhance the HIV-1-specific immune responses induced by an mRNA vaccine that might be applicable to human vaccination programs with mRNA and MVA vectors.

Production and characterisation of a candidate hyper-immune serum for the replacement of the Bordetella pertussis mouse antiserum Biological Reference Preparation.

For acellular pertussis (aP) vaccines, the current European Pharmacopoeia (Ph. Eur.) monograph Pertussis vaccine (acellular, component, adsorbed) (1356) requires an immunogenicity assay in mice or guinea pigs to assess the potency of each lot of vaccine (Ph. Eur. general method 2.7.16. Assay of pertussis vaccine (acellular)). This biological assay, carried out on the final bulk of the vaccine lot, is based on the measurement of the specific antibody response to the 5 antigenic components (pertussis toxin (PT), Fimbrial haemagglutinin (FHA), pertactin (PRN) and Fimbriae 2 and 3 (FIM2/3)) that are present in the combined aP vaccines. In the mouse assay, serum antibody levels are measured by ELISA. The immunogenicity of a vaccine under test is estimated versus a homologous reference vaccine and a reference antiserum e.g. the first Ph. Eur. Biological Reference Preparation for Bordetella (B.) pertussis mouse anti-serum (BRP1), established in 1998, is used to normalise the titre of antibodies (expressed in ELISA Units (ELU)/mL). In anticipation of the depletion of BRP1 stocks, a project was launched in 2013 by the Biological Standardisation Programme (BSP) of the European Directorate for the Quality of Medicines & HealthCare (EDQM) in order to establish a new standardised reference serum. The project, referred to herein as BSP129, was conducted in 2 phases: 1) the production and characterisation of a mouse serum pool (using a multicomponent aP vaccine marketed in Canada similar to the vaccine used in the BRP1 production as immunogen) and of candidate BRP batches (cBRPs) and 2) an international collaborative study aimed at calibrating the cBRPs in terms of antibody levels against PT, FHA, PRN and FIM2/3. This article presents the design and results of the first phase of the collaborative study to establish the optimal conditions for immunisation and bleeding of mice in order to produce a large pool of hyper-immune serum against the 5 antigens. After the characterisation of this pool, cBRP pilot lots were manufactured by freeze-drying diluted solutions of the hyper-immune serum pool. The pilot lots were then characterised in two Official Medicines Control Laboratories (OMCLs) for their antibody contents against aP vaccine antigens using in-house ELISA (based on methods developed by 2 European vaccine manufacturers) and Multiplex Immunoassay (MIA) methods. The antibody titres recovered demonstrated that a dilution factor of 1/40 could be considered for the scaled-up manufacture of candidate reference preparations (cBRPs). Three batches (15 000 vials) of cBRP were manufactured and fully characterised. In light of the data obtained, and although titration results between the ELISA methods were sometimes discrepant, it was agreed that the establishment study (phase 2) could be launched. Real-time and accelerated stability studies were also included in the first study phase to document the stability of the cBRPs in freeze-dried form and after reconstitution and storage at -20°C±5°C. The results showed that the stability of the freeze-dried cBRPs at usual storage and shipment temperatures is acceptable and that reconstituted cBRP solutions are stable for 12 months at -20°C±5°C. It could therefore be recommended to freeze small aliquots of the 1 mL solution obtained by the reconstitution of one BRP vial in order to store them for use in separate assays. With the application of this strategy, the stocks of the BRP1 replacement batches should cover the needs of OMCLs and manufacturers for at least the next decade.

Establishment of Ph. Eur. Bordetella pertussis mouse antiserum Biological Reference Preparation batches 2, 3 and 4.

A project aimed at establishing replacement batches for the European Pharmacopoeia (Ph. Eur.) Biological Reference Preparation (BRP) Bordetella (B.) pertussis mouse antiserum was started in 2013 under the aegis of the Biological Standardisation Programme (BSP) of the European Directorate for the Quality of Medicines & HealthCare (EDQM). This BRP is used for the immunogenicity assay in mice to assess the potency of acellular pertussis (aP) vaccines as described in Ph. Eur. general method 2.7.16. Assay of pertussis vaccine (acellular). In a preliminary phase of the project (referred to herein as BSP129 phase 1) a hyper-immune serum pool was produced in mice using a combined aP vaccine as immunogen. This pool was used to generate 3 freeze-dried candidate (c) B. pertussis anti-mouse serum BRP batches (cBRP2, cBRP3 and cBRP4). After the pre-qualification that showed their suitability as candidate batches, an international collaborative study (BSP129 phase 2) was carried out in order to standardise these 3 batches against the current BRP1 in terms of anti-PT, -FHA, -PRN and -FIM2/3 antibody contents. For the sake of continuity with the standardisation of BRP1, the corresponding WHO standard (1RR 97/642) was introduced as a second reference for the calibration of the 3 candidate BRPs. Eleven laboratories took part in phase 2. Ten of them performed the ELISA method they use routinely for aP vaccine batch release and one laboratory performed the Multiplex Immunoassay (MIA) as an alternative test. Four participants titrated the antibodies against all 5 pertussis antigens, 5 participants determined the antibody content against 3 antigens (PT, FHA, PRN), one participant titrated the antibodies against PT and FHA antigens and one laboratory determined the antibody content for the PT antigen only. Details of all ELISA methods used were analysed to evaluate their impact on the calibration of the cBRPs. The variability of the results in relation to the nature and methodology of the tests appeared rather limited. Discrepant titres of cBRPs were measured depending on the reference used: the use of the 1RR induced an overestimation (in 8 out of 11 laboratories) and a large inter-laboratory variation in the calculated titres. Regardless of the reference used, equivalency between the calculated titres of cBRP2 and cBRP3 was observed, whilst cBRP4 had systematically lower titres for all antibodies against the 5 acellular pertussis vaccine components. Based on these observations, it was decided to establish the candidate BRP batches against BRP1 and to assign the following potencies based on the mean values determined through centrally calculated results of the calibration assays performed by ELISA in BSP129 phase 2: For cBRP2 and cBRP3 Anti-pertussis toxin: 37 ELISA Units (ELU) per vial Anti-filamentous haemagglutinin: 114 ELU per vial Anti-pertactin: 44 ELU per vial Anti-fimbrial agglutinogens (FIM2/3): 25 ELU per vial For cBRP4 Anti-pertussis toxin: 32 ELU per vial Anti-filamentous haemagglutinin: 98 ELU per vial Anti-pertactin 38 ELU per vial Anti-fimbrial agglutinogens (FIM2/3):23 ELU per vial In February 2018, BRP2, BRP3 and BRP4 were adopted by correspondence by the Ph. Eur. Commission.

Combined vaccines for prophylaxis of infectious conditions.

In recent years, the application of vaccines shows limitations, including the high number of vaccine administrations and the fear of safety and effectiveness. In this regard, advanced vaccine products have been developed, like the combined vaccines, or are under development, such as nucleic acid vaccines (DNA and RNA), polymer-based vaccines, etc. Moreover, the possible use of traditional, like aluminium hydroxide and aluminium phosphate, or innovative adjuvants, like monophosphoryl lipid A, polysaccharides and nanoparticulate system, may further increase vaccine effectiveness. This review article focuses on the combined vaccines, which, especially when they are associated with adjuvants, reduce the dosing frequency, and prolong the duration of action, thus providing better vaccine coverage. Marketed preparations, like Typhim Vi, Peda typh and Boostrix showed better vaccine coverage for diseases like typhoid, tetanus, diphtheria and acellular pertussis. The future aspect for the development of combined vaccines will protect not only against infectious diseases but likely even against various infectious conditions, like pneumonia, meningococcal infection and respiratory syncytial virus infection.

A concise review of vaccines against Mycoplasma hyopneumoniae.

Mycoplasma hyopneumoniae (Mhp) is the pathogen of Mycoplasmal pneumonia of swine (MPS), a chronic respiratory infectious discease which causes enormous losses to the swine industry worldwide. At present, vaccination is the most effective mean to prevent and reduce economic losses caused by this pathogen. Currently, MPS vaccines mainly include inactivated vaccines and attenuated live vaccines. However, these approved vaccines still have many drawbacks, and the infection of Mhp has not yet been fully elucidated. Adhesion factors of Mhp have been shown to play a direct role in the pathogen's adherence, and thus were given consideration to be included in the composition of the vaccine. This shows a good prospect due to the advantages and feasibility of genetically engineering a vaccine. In this review, we summarize the work of researchers in recent years about the development of vaccines against Mhp, and we focus on the development of genetically engineering vaccines and some novel combined vaccines.

Combination vaccine strategies to prevent enteric infections.

New vaccine candidates entering the current routine immunization schedule can best be accommodated as combination vaccines. A combined Shigella and enterotoxigenic E. coli (ETEC) vaccine could greatly benefit children in disease-endemic areas. New candidates are getting closer to being able to meet these needs, but they raise numerous strategic questions related to presentation, formulation, and regulatory approach. The "Combination Vaccine Strategies to Prevent Enteric Infections" workshop at the 2016 Vaccines Against Shigella and ETEC (VASE) Conference examined some of the considerations for developing such vaccines against enteric pathogens.

Display of ISKNV orf086 protein on the surface of Aeromonas hydrophila and its immunogenicity in Chinese perch (Siniperca chuatsi).

Co-infection with infectious spleen and kidney necrosis virus (ISKNV) and Aeromonas hydrophila is becoming ever more widespread in Chinese perch (Siniperca chuatsi) aquaculture industry, so that it's necessary to develop the combined vaccine against ISKNV and A. hydrophila disease. The surface display of heterologous on bacteria using anchoring motifs from outer membranes proteins has already been explored as an effective delivery system of viral antigens. In present study, the ISKNV orf086 gene, which is verified as a protective antigen, was inserted into ompA gene cassette of A. hydrophila GYK1 strain by homologous recombination. And an ompA-orf086 fusion A. hydrophila mutant strain K28 was constructed. Then the ISKNV orf086 was verified to express on the surface of A. hydrophila K28 by RT-PCR, western blot and indirect immunofluorescence assay. Next, Chinese perch were intraperitoneally inoculated with formalin inactivated A. hydrophila k28 emulsified with ISA763 adjuvant with a dose of 9 × 10(8) CFU per fish. Transcriptional analysis of non-specific and specific immune related genes revealed that the expression levels of IRF-7, IRAK1, Mx, Viperin, Lysozyme and IgM were strongly up-regulated in Chinese perch post-inoculation. In addition, specific antibodies were detected by ELISA, and the results showed that antibody titer against ISKNV or A. hydrophila reached the highest with 1:800 or 1:1200 on 14dpv, respectively. Lymphocyte proliferation were detected by MTT methods, and the results showed that the SI values of AH-K28 vaccinated group to three different stimulators were significantly higher than those of control group. At last, protective efficacy were determined by challenge trials. The cumulative mortality rates of vaccinated groups were significantly lower than the control one (P < 0.05) after ISKNV or A. hydrophila challenge, and the relative percentage survival (RPS) value was 73.3% and 60%, respectively. This system provides a novel approach to the surface display of heterologous antigenic proteins on A. hydrophila and suggests the possibility to use the recombinant K28 strain as a combined vaccine against ISKNV and A. hydrophila infection.

Status of vaccine research and development for Shigella.

Shigella are gram-negative bacteria that cause severe diarrhea and dysentery. In 2013, Shigella infections caused an estimated 34,400 deaths in children less than five years old and, in 2010, an estimated 40,000 deaths in persons older than five years globally. New disease burden estimates from newly deployed molecular diagnostic assays with increased sensitivity suggest that Shigella-associated morbidity may be much greater than previous disease estimates from culture-based methods. Primary prevention of this disease should be based on universal provision of potable water and sanitation methods and improved personal and food hygiene. However, an efficacious and low-cost vaccine would complement and accelerate disease reduction while waiting for universal access to water, sanitation, and hygiene improvements. This review article provides a landscape of Shigella vaccine development efforts. No vaccine is yet available, but human and animal challenge-rechallenge trials with virulent Shigella as well as observational studies in Shigella-endemic areas have shown that the incidence of disease decreases following Shigella infection, pointing to biological feasibility of a vaccine. Immunity to Shigella appears to be strain-specific, so a vaccine that covers the most commonly detected strains (i.e., S. flexneri 2a, 3a, 6, and S. sonnei) or a vaccine using cross-species conserved antigens would likely be most effective. Vaccine development and testing may be accelerated by use of animal models, such as the guinea pig keratoconjunctivitis or murine pneumonia models. Because there is no correlate of protection, however, human studies will be necessary to evaluate vaccine efficacy prior to deployment. A diversity of Shigella vaccine constructs are under development, including live attenuated, formalin-killed whole-cell, glycoconjugate, subunit, and novel antigen vaccines (e.g., Type III secretion system and outer membrane proteins).

Status of vaccine research and development for enterotoxigenic Escherichia coli.

Enterotoxigenic Escherichia coli (ETEC) is one of the most common bacterial causes of diarrhea-associated morbidity and mortality, particularly among infants and young children in developing countries. Still, the true impact on child and traveler health is likely underestimated. There are currently no licensed vaccines for ETEC, but studies indicate high public health impact, cost-effectiveness, and feasibility of immune protection through vaccination. ETEC vaccine development remains a World Health Organization priority. Traditionally, ETEC vaccine development efforts have focused on inducing antitoxin and anticolonization antigen immunity, as studies indicate that antibodies against both antigen types can contribute to protection and thus have potential for vaccines. Leading cellular vaccine candidates are ETVAX (a mixture of four inactivated strains) and ACE527 (a mixture of three live attenuated strains), both of which have been found to be safe and immunogenic in Phase 1/2 trials. ETVAX is the furthest along in development with descending-age studies already underway in Bangladesh. Other ETEC vaccine candidates based on protein subunits, toxoids (both LT and ST), or novel, more broadly conserved ETEC antigens are also under development. Of these, a protein adhesin-based subunit approach is the most advanced. Impact and economic models suggest favorable vaccine cost-effectiveness, which may help expand market interest in ETEC vaccines. Combination vaccine formulations may help improve the economic case for development and use, and better point-of-care diagnostics will help to raise awareness of the true health burden of ETEC and highlight the potential public health benefit of ETEC vaccine introduction. Better diagnostics and vaccine demand forecasting will also improve vaccine development financing and support accelerated uptake once a licensed vaccine becomes available.

Hexavalent vaccines for immunization in paediatric age.

Despite the potential for protection against a broad spectrum of pathogens, the availability of an increased number of effective vaccines could lead to a significant reduction in vaccination coverage as the result of issues with implementation of new vaccines within existing protocols. To overcome these problems, the development of combined vaccines has been promoted. The use of combined vaccines offers a number of potential benefits, including a reduction in the number of patient visits, reduced complications associated with multiple intramuscular injections, decreased costs of stocking and administering separate vaccines, and a lowering of the risk of delayed or missed vaccinations. The hexavalent vaccine includes antigens against diphtheria, tetanus, acellular pertussis (DTaP), hepatitis B (HBsAg), poliomyelitis (P1, P2, P3) and Haemophilus influenzae type B (Hib) infections. The primary goal of this review is to discuss the immunogenicity, efficacy, safety and tolerability of several hexavalent preparations that are either commercially available or still under development.