Assessment of vaccine efficacy by challenge studies in man.
D002986:Clinical Trials as Topic; D005069:Evaluation Studies as Topic; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage; D007251:Influenza, Human / Q000517:prevention & control*; D014611:Vaccination; D014613:Vaccines, Attenuated / Q000008:administration & dosage
D007252:Influenza Vaccines; D014613:Vaccines, Attenuated