Q: Our paediatrician says it is necessary to get the child vaccinated for typhoid every 2 years. We had given this vaccine to our son when he was two and a half years old. Now he is 5. Is the vaccine due again? From where can I get the detailed immunisation chart?

A:Yes, the immunity wanes off and a booster is required every 2-3 years. You could try the Indian Academy of Paediatrics website for the chart.