High morbidity and mortality among pregnant women are characteristic identifiers of
waterborne epidemic outbreaks of hepatitis E. 1, 2 In the absence of effective treatment,
vaccination offers a potential means to reduce the morbidity and mortality associated with
pregnancy. 3 However, clinical studies are hampered by safety concerns, because
vaccination during pregnancy is generally contraindicated. A review of the records of a
recent phase 3 clinical trial of the recombinant hepatitis E vaccine3 identified 37 of 31,791 …