30 ( 3.7 % , 95 % CI 2.5-5 .2 ) participants in the LT-patch group and 46 ( 5.6 % , 4.1-7 .4 ) in the placebo group had moderate or severe ETEC diarrhoea ( vaccine efficacy 34.6 % , -2.2 to 58.9 ; p = 0.0621 ) .