Recombinant vaccine against hepatitis E: duration of protective immunity in rhesus macaques.
Zhang M, Emerson SU, Nguyen H, Engle R, Govindarajan S, Blackwelder WC, Gerin J, Purcell RH. Recombinant vaccine against hepatitis E: duration of protective immunity in rhesus macaques. Vaccine. 2002 Sep 10; 20(27-28):3285-91.