Antibody responses in cholera patients.

Haemagglutinating, vibriocidal and mouse protective antibody responses in cholera patients were found to be maximum on the 7th day of admission. The mouse protective antibody on the first day at the hospital was lower than those of human volunteers. The circulating antibodies in the patients declined to normal levels or lower than normal before 3 months after the acute onset.

Assessment of antibody responses and protective immunity in cholera vaccinated subjects.

Cross-reactive antibody responses were assessed in volunteers vaccinated with classical Inaba and Ogawa cholera vaccines. The El Tor, Ogawa vibrios, the most often biotype, and serotype found to be the causative agent of cholera in Thailand, or their product were used throughout the in vitro and in vivo tests. The test involved were the passive hemagglutination test, vibriocidal tests and the mouse protection test. Classes of specific immunoglobulins produced in the volunteers were determined using anti-immunoglobulin enhancement of hemagglutination. It was found that the levels of hemagglutinating and vibriocidal antibodies reached their peaks on day 7 after the vaccination and were statistically constant for 3 months. Significant decrease was observed thereafter. The mouse protective antibody titer was highest at 1 month after the vaccination then declined significantly at the 6th month. Classes of specific immunoglobulins were found to be either IgM or IgG alone or mixture of both.