Passive immunity to fatal reovirus serotype 3-induced meningoencephalitis mediated by both secretory and transplacental factors in neonatal mice.

or virus dissemination, yetvirus wasrecovered fromneonatal intestines. Miceimmunized withheterotypic virus byeither thesubcutaneous ortheoralroutealsoconferred protection against disease; however, virus was recovered insmall intestines andlivers ofinfected neonates. Basedonresults fromfoster-nursing experiments, itappears thatfactors obtained bothduring suckling andbytransplacental transfer contribute toprotection. Passive transfer ofreovirus-immune mouseserumalsoprotected neonates fromdisease. Theseresults demonstrate that passive immunemechanisms canmediate theprotection ofneonates against reovirus infection andprovide further evidence oftheimportance ofthemucosal immuneresponse inprotection against pathogens thatinvade thehostviamucosal tissues.