Susceptibility of Human Volunteers With Different Histo-Blood With Different Histo-Blood Group Antigens to Norovirus

Study Summary

Objectives: To evaluate the role of human histo-blood group antigens in susceptibility to Norovirus infections. Description of Study Design: Healthy volunteers with different blood types and low antibody titers to the challenge strain will be challenged orally with a Norovirus in the CCCR inpatient facility. Subjects with resistant (non-secretors) or susceptible (secretors (of either A, B or O blood group)) to the challenge strain will be recruited. The challenge study will be conducted in two groups of twenty, each with approximately ten secretors and ten non-secretors. Three additional subjects per group will serve as alternates in the event that any of the study subjects are unavailable or become ineligible at the time of the inpatient study. Subjects will be monitored daily in the isolation facility for at least five days following this challenge for daily clinical and virological evaluations. Subjects will return to the investigational site for evaluation the day after discharge from the inpatient unit and about 30 days (28-35 days) post challenge. Study Endpoints: Norovirus infection as assessed by viral shedding, seroconversion and clinical illness assessed by the duration and severity of symptoms

Primary Outcome

The number of subjects that become infected, as measured by the number of subjects found to be shedding norovirus in their stool, as well as the number of symptomatic infections (viral shedding in addition to other symptoms such as vomiting, diarrhea, abdominal cramps) will be the primary outcome measure. We will also assess the number of subjects who show at least a 4-fold rise in antibodies against Norovirus (comparing pre-challenge and post-challenge antibody levels).

Interventions

• BIOLOGICAL Norovirus