Predictors of human norovirus infection and immunity (133.52)

Abstract Noroviruses (NoV) are the main cause of epidemic gastroenteritis worldwide. We have previously shown that both an individual's secretor status (genetic) and induction of Norwalk virus-specific salivary IgA (immune) are important predictors of infection with Norwalk virus (NV). We still do not understand the factors that mediate the immune response, and infection, to Norwalk virus. To address this need, we have extended our analysis of immunological, genetic, and demographic parameters of 109 volunteers challenged with various doses of Norwalk virus through univariate and multivariate regression analyses. We found that gender, ethnicity, levels of pre-challenge NV-specific serum IgG or levels of pre-challenge NV-specific salivary IgA were not significant predictors of infection or development of a NV-specific antibody response. The presence but not magnitude of pre-challenge serum NV-specific IgG and secretor positive status were significantly associated with infection. Dose of inoculum received and age of the individual may also be predictors of infection and development of an NV-specific antibody response. We observed significant collinearity between the age of the volunteer and the presence of pre-challenge serum NV-specific IgG. Lastly, we found a strong association between levels of salivary and serum NV-specific antibody levels, after adjusting for covariates. Taken together, these data will be used to better understand the immune response to NV infection and design effective NoV vaccines to protect at risk populations including children, food handlers, and the elderly.