<prompt> Peusis affects which age -3-Feb57-May10 years  <response>: Ans. is b i.e., 5 o In prevaccine era, and in countries where immunization is limited the peak incidence of peussis is in children 1-5 years of age, infant accounts for 15 of cases. o In recent years, where vaccination is employed, approximately one half of cases have occuured in infants younger than 1 year of age and one fouh in adolescent and adults. 