system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 3 year old child is brought to the outpatient depament with upper respiratory tract infection. On asking about his previous immunization history, it is found that he has had no primary immunizations from bih. What is the most appropriate step in the management of this patient?
assistant
The correct answer is  If a child comes with no previous immunizations, then catch-up immunizations of BCG, OPV, DPT and measles vaccines along with vitamin A must be given at the time of visit to the clinic. Advise the parents to bring the child after 4 weeks for OPV-2 and DPT-2, and after a fuher 4 weeks for OPV-3 and DPT-3. Booster dose or fouh dose is given after a minimum interval of 6 months. The fifth dose is not needed if the fouh dose was given at 4 years or older. Ref: Ghai Essential Pediatrics, By O. P. Ghai, Piyush Gupta, V. K. Paul, 6th Edition, Page 121, 191, 200; Nelson Textbook of Pediatrics, By Kliegman, Stanton, St. Geme, Schor, Behrman, 19th Edition, Page 890.