9th month immunization given is
High-Yield Explanation
The principal problem of measles immunization is timing; immunization before the age of 9 months runs the risk of the vaccine being rendered ineffective by the natural antibodies acquired through the mother. Immunization later than 9 months means a significant propoion of children will contract measles in the interval between the wearing of natural protection and the introduction of the vaccine. (refer pgno:149 park 23 rd edition)