ABSTRACT
The heat-killed, phenolized parenteral typhoid vaccine was tested in informed volunteers. Assessment for its immunogenicity was performed using Widal test and enzyme-linked immunosorbent assay (ELISA). The anti-H antibody, which is a marker of the vaccine antigenicity peaked at one month after the vaccination and appeared throughout the one year course of the study. The anti-O antibody peaked at 7th day after vaccination and lasted only for 6 months. Classes of specific antibodies were determined by ELISA using single extracted lipopolysaccharide from Salmonella typhi 0901 as antigen. The possible protective role of serum derived intestinal IgG and IgA were discussed. Based on the agglutinating antibodies, the results indicate that the heat-killed, phenolized typhoid vaccine conferred at least 6 months protective period.
Subject(s)
Antibodies, Bacterial/analysis , Antibody Formation , Bacterial Vaccines/immunology , Enzyme-Linked Immunosorbent Assay , Hot Temperature , Humans , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Lipopolysaccharides/immunology , Phenol , Phenols/pharmacology , Salmonella typhi/immunologyABSTRACT
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.
Subject(s)
Animals , Antibodies, Bacterial/analysis , Cholera/immunology , Hemagglutination Tests , Humans , Immunoglobulins/analysis , Time FactorsABSTRACT
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.