Effect of Raw Milk on the Immune Response Upon Cholera Vaccination

Inclusion Criteria: * Age 18-50 yr * Signed informed consent * Availability of internet connection * Male or female * Willing to stop blood donation at the blood bank during the study period Exclusion Criteria: * Currently participating in another clinical trial * Previous Cholera, Salmonella, or E. coli vaccination * Tonsillectomy * Acute gastroenteritis in the past 2 months * Use of antibiotics in the past 2 months * Hypersensitivity to the vaccine, to formaldehyde or to any of the excipients (sodium salts) * Pregnancy or lactating (pregnancy test will be performed on the vaccination days) * Not willing to drink raw milk * Allergic to milk or lactose-intolerant * Disease of GI tract, liver, gall bladder, kidneys, thyroid gland * Immune-compromised * Use of immunosuppressive drugs * Drug abuse, and not willing/able to stop this during the study * Excessive alcohol usage (men: \>4 consumptions/day or \>20 consumptions/week; women: \>3 consumptions/day or \>15 consumptions/week)