Observations on Serological Responses to Cholera Immunization

Abstract

Summary A comparison of the serological responses to several cholera vaccines and vaccine regimens has been conducted in groups of people in the Philippines. Responses to the vaccines and vaccine regimens, as determined by agglutination and vibriocidal antibody titrations, were observed to differ depending on the vaccine and dosage employed. Those vaccines which were most potent in active mouse protection assays elicited the best responses in the human subjects. Single doses of suitable vaccines were found to give nearly 100% serological response in small groups of individuals. Tests on a vaccine composed of El Tor vibrios showed it to be a safe and potent antigen in humans. It is recommended that consideration be given to the inclusion of El Tor vibrios in cholera vaccines for general use, although locally, in outbreaks of El Tor cholera, exclusive use of an El Tor vaccine would seem justified by the results of this investigation.