Comparative efficacy of two, three, or four doses of TY21a live oral typhoid vaccine in enteric-coated capsules: a field trial in an endemic area.

@article{Ferreccio1989ComparativeEO,
  title={Comparative efficacy of two, three, or four doses of TY21a live oral typhoid vaccine in enteric-coated capsules: a field trial in an endemic area.},
  author={Catterine Ferreccio and Myron M. Levine and Herminia Rodr{\'i}guez and Rafael A. Contreras},
  journal={The Journal of infectious diseases},
  year={1989},
  volume={159 4},
  pages={766-9}
}