Enhancement of Vaccine-Induced T-Cell Responses by Probiotics in Calves.

Calves have immature immune systems, hence immunization with vaccines is essential to protect them from infectious diseases. However, immune responses to vaccines vary widely among individuals. Therefore, strategies for enhancing vaccine efficacy are needed, particularly those targeting low responders to vaccines. Probiotics have attracted attention because of their beneficial immunomodulatory effects on the host. Although probiotics may improve calf immunity, their potential to enhance immune responses to vaccines in calves remains unclear. Thus, we investigated whether immune responses to vaccines, especially T-cell responses, are enhanced when calves receive a combination of probiotic supplementation and vaccination.