Gilbert M. Schiff

A human volunteer challenge model using frozen bacteria of the new epidemic serotype, V. cholerae O139 in Thai volunteers.

A total of 35 volunteers were recruited for an IRB-approved inpatient dose-escalation challenge. The goal was to identify a dose that produced an observed cholera attack rate > or =80% and an illness of sufficient severity during the defined study period such that the model would be useful for determining vaccine protection. Volunteers were challenged in groups of 5 with V. cholerae O139 that had been reconstituted immediately before use. Only 2 out of 5 volunteers who received the lowest dose (4.3 x 10(4) cfu) had diarrhea. As the inoculum size increased, the attack rate of diarrhea increased to 3-4 of 5 volunteers. At the highest dose tested, approximately 5 x 10(7) cfu, the attack rate was 73%. We recommend the use of frozen V. Cholera O139 in a human experimental challenge model to assess cholera vaccine efficacy (VE) in a cholera endemic area but with 4 days observation period before initiation of tetracycline to allow assessment of severity.

Follow-up studies of rubella vaccinees at adolescence

This report provides the results of follow-up surveillance and postvaccination rubella HI antibody studies on adolescent girls in Cincinnati.

Evaluation of a trivalent measles, mumps, rubella vaccine in children

Vaccine. The vaccine was a combination of Schwarz strain live, attenuated measles virus, 2 Jeryl Lynn strain five, attenuated mumps virus? and Cendehill strain live, and attenuated rubella virus? Three different production lots were used in this study. All lots contained at least 1,000 50% tissue culture infective doses of measles and rubella viruses and 5,000 TCIDs0 of mumps virus. The trivalent vaccine was dispensed into single dose vials, lyophilized, and stored at 5~ until administered. Placebo. The placebo used in the study was identical to the vaccine in all respects except it did not contain virus. Serology. All serologic assays were performed in the Assay Laboratory of The Dow Chemical Company in Zionsville, Indiana. Antibodies to measles and rubella viruses were determined by the hemagglutination inhibition method in microtiter plates?, 6 Four units of hemagglutination antigen were used; the end point was taken as the highest serum dilution that completely inhibited

Evaluation of rubella vaccination in a large school system

An evaluation of rubella vaccine was conducted in a large school system to determine the antigenic effect, the presence of transmission of vaccine virus to susceptible contacts, the morbidity caused by the vaccine, and the acceptability by the community of vaccine evaluation. Cendehill strain live, attenuated rubella vaccine was used. The study was placebo controlled. A total of 7,238 children participated in the study. The vaccine was highly antigenic; 96.8 per cent of the susceptible vaccines developed a significant serum antibody titer. Nine per cent of the susceptible children receiving placebo also developed significant serum antibody titer. Spread of rubella virus from the vaccinees could not be ruled out. There was little morbidity associated with vaccination. Generalized urticaria occurred in 2 vaccinees several weeks after vaccination. The study was well received by the community.