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Interpretive Summary: Concomitant versus separate vaccination against brucellosis and clostridia in dairy heifers

By: Anne Kamiya, MS

Brucellosis is a bacterial disease contracted from consuming raw or unpasteurized dairy products from infected animals. Cattle with brucellosis may have increased rates of infertility and in female cattle, increased perinatal mortality. Clostridiosis is another zoonotic bacterial infection that can infect both humans and cattle. Vaccination against these organisms is therefore necessary to prevent disease in livestock and for food safety reasons.  

Researchers studied how concomitant versus separate vaccination against brucellosis and clostridiosis affected the intake, performance, behavior and immune responses of dairy calves in this recent Journal of Animal Science study. Each vaccine stimulates different parts of the immune system. When given concomitantly the impacts and effectivity of multiple vaccinations on cattle is an area of study that has not yet been explored. It was hypothesized that intake, performance and feeding behavior of cattle would not be affected regardless of vaccination schedule, but that concomitant vaccination would hinder the immune response because the clostridia vaccine stimulates a T-helper 1 immune response whereas the brucellosis vaccine stimulates a T-helper 2 immune response.

A total of 50 dairy heifers were given vaccinations against brucellosis and clostridia concomitantly or vaccination against only brucellosis or only clostridia.  Feed intake, performance and feeding behavior were unaffected regardless of vaccine schedule. Lower antibody titers against clostridia were noted in animals given concomitant vaccination, indicating that effectivity of the vaccination against clostridial infections was negatively impacted.

The results of this study suggest that vaccinating dairy heifers concomitantly against clostridial infections and brucellosis may negatively impact the immune response to and effectivity of the clostridial vaccine. Based on the results of this study, administration of these vaccines at different time points may be ideal. More studies into how concomitant versus separate vaccinations impact the immune system and its ability to develop antibodies may be warranted.  

The full paper can be read on the Journal of Animal Science webpage.