71 events of severe rotavirus gastroenteritis were reported in 4752 person-years in infants in the vaccine group compared with 76 events in 2360 person-years in those in the placebo group ; vaccine efficacy against severe rotavirus gastroenteritis was 536 % ( 95 % CI 350-669 ; p = 00013 ) and 564 % ( 366-701 ; p < 00001 ) in the first year of life .