Rapid test to detect cytotoxic activity in vaccines against foot-and-mouth disease / Prova rápida para detectar atividade citotóxica em vacinas para febre aftosa

Substances with cytotoxic activity present in vaccines against the foot-and-mouth disease may interfere with methods used to detect residual live virus in the product or cause undesirable postvaccination reactions. This study describes a rapid in vitro test to detect cytotoxic activity in water-in-oil vaccines against foot-and-mouth disease using a commercial saponin as a cytotoxic agent and a solution of sheep's red blood cells as substrate. Hemolytic and cytotoxic activity was analyzed using experimental and commercial vaccines prepared with and without saponin. The hemolytic and cytotoxic potential of preparations containing saponin was evident. In contrast, hemolytic and cytotoxic activities were not observed in vaccines without saponin in their composition. The method described here allows to easily detect if the vaccine under study has cytotoxic activity, making it possible to select the most appropriate method to process the sample to be used for the innocuity test. Additionally, due to undesirable effects that may be observed in animals receiving vaccines containing saponin in their formulation, the use of the rapid test described here allows to identify those vaccines with cytotoxic activity and to verify the presence of saponin on them, through the mass spectrometry method.(AU)

Substâncias com atividade citotóxica presentes em vacinas contra febre aftosa podem interferir com o método utilizado para a detecção de vírus ativo residual no produto ou causar reações pós-vacinais indesejáveis. O presente trabalho descreve uma prova rápida in vitro para detectar atividade citotóxica em vacinas oleosas contra febre aftosa utilizando uma saponina comercial como agente citotóxico e uma solução de hemácias de carneiro como substrato. Analisaram-se as atividades hemolítica e citotóxica utilizando-se vacinas experimentais e comerciais preparadas com e sem saponina. O potencial hemolítico e citotóxico dos preparados que continham saponina na sua formulação foi evidente. Em contraste, não se observou atividade hemolítica e citotóxica nas vacinas sem saponina. O método descrito permite conhecer rapidamente se a vacina em estudo apresenta atividade citotóxica e, dessa maneira, selecionar o método mais adequado para processar a amostra que será utilizada para investigar a presença de vírus ativo residual. Adicionalmente, devido aos efeitos indesejáveis que podem ser observados em animais que recebem vacinas que contêm saponina na sua formulação, o uso da prova rápida descrita permite selecionar aquelas vacinas com atividade citotóxica para posteriormente verificar a presença de saponina através de técnicas analíticas como a espectrometria de massas.(AU)

Rapid test to detect cytotoxic activity in vaccines against foot-and-mouth disease / Prova rápida para detectar atividade citotóxica em vacinas para febre aftosa

Substances with cytotoxic activity present in vaccines against the foot-and-mouth disease may interfere with methods used to detect residual live virus in the product or cause undesirable postvaccination reactions. This study describes a rapid in vitro test to detect cytotoxic activity in water-in-oil vaccines against foot-and-mouth disease using a commercial saponin as a cytotoxic agent and a solution of sheep's red blood cells as substrate. Hemolytic and cytotoxic activity was analyzed using experimental and commercial vaccines prepared with and without saponin. The hemolytic and cytotoxic potential of preparations containing saponin was evident. In contrast, hemolytic and cytotoxic activities were not observed in vaccines without saponin in their composition. The method described here allows to easily detect if the vaccine under study has cytotoxic activity, making it possible to select the most appropriate method to process the sample to be used for the innocuity test. Additionally, due to undesirable effects that may be observed in animals receiving vaccines containing saponin in their formulation, the use of the rapid test described here allows to identify those vaccines with cytotoxic activity and to verify the presence of saponin on them, through the mass spectrometry method.(AU)

Substâncias com atividade citotóxica presentes em vacinas contra febre aftosa podem interferir com o método utilizado para a detecção de vírus ativo residual no produto ou causar reações pós-vacinais indesejáveis. O presente trabalho descreve uma prova rápida in vitro para detectar atividade citotóxica em vacinas oleosas contra febre aftosa utilizando uma saponina comercial como agente citotóxico e uma solução de hemácias de carneiro como substrato. Analisaram-se as atividades hemolítica e citotóxica utilizando-se vacinas experimentais e comerciais preparadas com e sem saponina. O potencial hemolítico e citotóxico dos preparados que continham saponina na sua formulação foi evidente. Em contraste, não se observou atividade hemolítica e citotóxica nas vacinas sem saponina. O método descrito permite conhecer rapidamente se a vacina em estudo apresenta atividade citotóxica e, dessa maneira, selecionar o método mais adequado para processar a amostra que será utilizada para investigar a presença de vírus ativo residual. Adicionalmente, devido aos efeitos indesejáveis que podem ser observados em animais que recebem vacinas que contêm saponina na sua formulação, o uso da prova rápida descrita permite selecionar aquelas vacinas com atividade citotóxica para posteriormente verificar a presença de saponina através de técnicas analíticas como a espectrometria de massas.(AU)

Investigating the temporal and spatial distribution of foot-and-mouth disease virus serotype C in the Region of South America, 1968-2016.

This study investigates the historical temporal trend and geographical distribution of the foot-and-mouth disease virus (FMDv) serotype C in South America; discussing the findings within the context of the actions and strategies carried out for the elimination of foot-and-mouth disease (FMD). This is the first time that such a comprehensive historical compilation has been carried out in the Region; hence, the study is intended as a reference and source of evidence about the presence/absence of FMDv serotype C in South America. Data on the occurrence of FMD were sourced from the Weekly Epidemiological Reports submitted by the countries to Pan American Foot-and-Mouth Disease Center (PANAFTOSA-PAHO/WHO) since 1972, and complemented with other sources of information from the 1968-1971 period. The temporal distribution was examined with local weighted regression (LOESS) to identify two temporal trends, that is, "smoothed" and "over-adjusted", utilising the time-series with the total number of cases per year, at Regional level. Thereafter the outbreaks were aggregated by decades and mapped by the first subnational administrative level. As a result, two major peaks of occurrence were identified, one in the 70s, with up to 1,193 outbreaks, and another in the 80s, with 380. Overall, the investigations show a clear regressive trend in the occurrence of serotype C, with a reduction in the number of outbreaks over-time, and with the subsequent reduction of affected locations. This study illustrates the contrast between the very limited presence over the last 20 years - with only one event in 2004 - and the epidemic situation in the 1970s and 1980s, and suggests that serotype C of FMDv is no longer present in the Region.

Protection induced by a commercial bivalent vaccine against Foot-and-Mouth Disease 2010 field virus from Ecuador.

Foot-and-Mouth Disease serotype O circulated endemically in Ecuador for many years, with an upsurge occurring in 2009. This manuscript describes retrospectively in vitro and in vivo laboratory studies to predict the field effectiveness of a commercial FMD vaccine to protect against the field strain, and explains the key actions and epidemiological strategies followed by the country to control the disease. The results established that the use of a good quality oil vaccine, manufactured with strains that were isolated long ago: O1 Campos Br/58 and A24 Cruzeiro Br/55; combined with the correct epidemiological strategies, are useful to control field strains when used in periodic biannual vaccination campaigns.

Genetic and antigenic relationships of vesicular stomatitis viruses from South America.

Vesicular stomatitis (VS) viruses have been classified into two serotypes: New Jersey (VSNJV) and Indiana (VSIV). Here, we have characterized field isolates causing vesicular stomatitis in Brazil and Argentina over a 35-year span. Cluster analysis based on either serological relatedness, as inferred from virus neutralization and complement fixation assays, or nucleotide sequences of two separate genes (phosphoprotein or glycoprotein) grouped the field isolates into two distinct monophyletic groups within the Indiana serogroup. One group included seven viruses from Brazil and Argentina that were serologically classified as Indiana-2 and Cocal virus (COCV). The other group contained three viruses from Brazil that were serologically classified as Indiana-3 and the prototype of this group, Alagoas virus (VSAV). Interestingly, two vesiculoviruses that were isolated from insects but do not cause disease in animals, one from Brazil (Maraba virus; MARAV) and the other from Colombia (CoAr 171638), grouped into two separate genetic lineages within the Indiana serotype. Our data provide support for the classification of viruses causing clinical VS in livestock in Brazil and Argentina into two distinct groups: Indiana-2 (VSIV-2) and Indiana-3 (VSIV-3). We suggest using nomenclature for these viruses that includes the serotype, year and place of occurrence, and affected host. This nomenclature is consistent with that currently utilized to describe field isolates of VSNJV or VSIV in scientific literature.

Characterization of the full-length genomic sequences of vesicular stomatitis Cocal and Alagoas viruses.

In Brazil and Argentina, vesicular stomatitis (VS) is caused by distinct viral strains serologically related to the classical vesicular stomatitis virus Indiana (VSIV), namely VS Indiana-2 (VSIV-2) and VS Indiana-3 (VSIV-3). Here we describe the full-length genomic sequences and organization of the prototype strains of VSIV-2 Cocal virus (COCV) and VSIV-3 Alagoas virus (VSAV). These viruses showed similar genomic organizations to VSIV field isolates except that the non-structural C'/C proteins, markedly conserved throughout the vesiculoviruses, were absent in VSAV. Phylogenetic analyses consistently grouped COCV, VSAV and VSIV in a monophyletic group distinct from VSNJV, supporting the classification of these viruses within the Indiana serogroup.

ELISA: Competición fase liquida (ELISA-CFL) y su uso en control de potencia de vacunas antiaftosa

Los progresos realizados en tecnología de productos biológicos y la demanda por parte del consumidor de aumentar la relación calidad/ precio, han impulsado no solamente un perfeccionamiento en las técnicas de control de calidad del producto final sino la implementación de sistemas de control de calidad del proceso de producción de los biológicos. En consecuencia el producto es totalmente monitoreado desde la materia prima utilizada en su producción hasta el producto final para consumo. Al ser empleado sistema de garantía de calidad durante el proceso de manufactura, el riesgo de obtener resultados negativos en el control del producto final se ha visto reducido o prácticamente eliminado para varios productos. Esta realidad permite que la calidad de los productos biológicos sea evaluada através del control de puntos críticos del proceso de producción de los mismos, eliminándose la necesidad de una rutina de control de calidad sobre el producto final.