Humoral Immunity to Enteric Viruses among Infants and Mothers in Bangladesh Abstract Diarrhea is a leading cause of death among children under five years of age worldwide. This problem is particularly acute in low and middle income (LMIC) countries where access to clean water, vaccines and medical care may be limited. Enteric human viruses, including adenovirus, astrovirus, norovirus, rotavirus and sapovirus are major causes of diarrheal incidence, morbidity and mortality along with bacteria and protozoa. Effective vaccines are needed for all of these viruses since the current rotavirus vaccine is not highly effective in LMIC and there are no approved vaccines for other enteric human viruses. Our primary goal is to discover specific antibody correlates of protection from infant viral diarrhea caused by these five viruses. We hypothesize that the antigens we identify will be excellent vaccine candidates for maternal and pediatric immunization. We will analyze the correlates of protection from gastroenteritis among the enteric virus antibody specificities found in breast milk, maternal sera and 18 week and one year old infant serum using an enteric virus protein microarray that we will construct. The array will contain all proteins and protein fragments from the five most common viral causes of diarrhea. The results will guide the development of vaccines against these important human pathogens.