Infections are an important worldwide cause of death, both in elderly and young children. Therefore, support of immunity could help to reduce the incidence of infections. To screen the potential of specific foods or food ingredients to support immunity, oral vaccination can serve as a model. In a previous study, this model was developed using oral cholera vaccination in human adult volunteers. In that study, raw milk was shown to support the immune response to vaccination. In this follow-up study, the effect of raw milk will be compared with pasteurized and ultra-heat treated (UHT) milk.