<prompt> If a 11 month old child has received two doses of DPT and polio, comes for fuher immunization after 5 months of the last dose, what should be done?Repeat the whole courseRepeat the 2nd dose and continue rest of the courseGive 3rd dose and continue the courseGive only booster dose  <response>: Interruption of the schedule with a delay between doses does not interfere with the final immunity achieved. Booster dose is sufficient. Ref: 25th edition, Parks Textbook of Preventive and Social Medicine, Page no. 134 