TbpBY167A-based vaccine is safe in pregnant sows and induces high titers of maternal derived antibodies that reduce Glaesserella parasuis colonization in piglets.

Glässer's disease is one of the main diseases affecting young piglets, particularly during the nursery phase, that can significantly impact pork production. Vaccination of sows has the potential to prevent Glaesserella parasuis infection during the first weeks of life that is to a substantial degree due to the transfer of maternal derived antibodies (MDA) in colostrum. In this study we compare the antibody response to two vaccines administered to pregnant sows. A subunit vaccine containing the mutant transferrin-binding protein, TbpBY167A, and an autogenous vaccine formulated with the LM96/20 strain of G. parasuis (SV4) administered on days 65 and 86 of the gestational period were safe and induced high titers of antibodies in sows. The IgG peak was reached on day 100 of gestation, and the translocation of IgG to the mammary gland was confirmed in colostrum at the time of delivery. Piglets born from vaccinated sows maintained positive IgG titers against TbpBY167A or G. parasuis SV4 for the duration of the experiment (35 days of life). Piglets born from sows vaccinated with the TbpBY167A-based vaccine had a significantly (p = 0.001) lower load of G. parasuis in the respiratory tract compared to those born from sows vaccinated with the autogenous vaccine. Finally, we demonstrate that the LM96/20 (SV4) strain is highly virulent and a primary agent of Glässer's disease.

Unusual high prevalence of antibodies to hepatitis E virus in South Brazil.

Hepatitis E virus (HEV) is worldwide distributed and might cause acute or chronic hepatitis mainly in immunocompromised individuals. In previous studies we found a high prevalence of antibodies to HEV within blood donors in south Brazil and also within backyard-raised pigs. Here, we aimed to investigate the prevalence of anti-HEV antibody and HEV RNA within the general population from three major municipalities (Caxias do Sul, Passo Fundo and Santa Maria) in south Brazil. A total of 3000 blood samples were randomly obtained from clinical laboratories at each of the three municipality (n = 1000 each) to determine the presence of anti-HEV antibodies and HEV RNA. Overall, anti-HEV antibodies were detected in 574/1000 (57,4%) samples in Caxias do Sul, 655/1000 (65.5%) samples in Passo Fundo and 554/1000 (55.4%) samples in Santa Maria. The prevalence of HEV-positive samples increased steadily and significantly (P < 0,001) with age and was unusually higher within individual over 40 years. Despite of this, none of the pooled serum samples had detectable levels of HEV RNA. The high anti-HEV antibody prevalence suggests that the virus might be present on the environment and/or foodstuff and poses a permanent threat to immune-compromised individuals.