Epidemiology of rotavirus in infants and protection against symptomatic illness afforded by primary infection and vaccination

This study assessed the frequency of symptomatic and asymptomatic primary a nd secondary infections with rotavirus in children under 24 months and dete rmined protection against symptomatic illness afforded by rhesus and human- rhesus rotavirus reassortant vaccines. Successive cohorts of children (n = 236) were followed through five winter rotavirus seasons with cultures of e ach reported episode of diarrheal disease and serologic determination of ro tavirus exposure on paired sera bracketing the winter. An average of 46% of children experienced rotavirus infection in each season with almost all in fected by two years of age. The relative risk of rotavirus associated gastr oenteritis in naive children versus naturally immune children was 2.4 (1.1, 5.3). The relative risk of rotavirus associated gastroenteritis in naive c hildren versus vaccinees was 4.1 (1.6, 10.7). In a community with predomina ntly serotype G1 rotavirus rhesus rotavirus-based vaccines are as protectiv e against rotavirus gastroenteritis as prior natural infection. (C) 1999 El sevier Science Ltd. All rights reserved.