Tom is a 9-year old boy who has never had an influenza vaccine. What dose and schedule of IIV should be administered to him?

For a 9-year-old boy who has never received an influenza vaccine, the recommended practice is to administer a dose of the inactivated influenza vaccine (IIV) now and not require a follow-up dose. Since he is younger than 10 years old and has not previously been vaccinated, he is eligible for a single dose of 0.5 mL.

In general, children aged 6 months to 8 years who have never been vaccinated against influenza or who have only received one dose in a previous season require two doses given at least 4 weeks apart. However, in this case, because Tom is already 9 years old and has not had any prior vaccinations, he only needs that single season dose of 0.5 mL. After this, he may receive annual vaccinations in subsequent seasons without the need for further doses unless indicated by additional circumstances, such as a change in vaccine guidelines.

This practice is consistent with the current recommendations for childhood immunizations, ensuring both effective protection against influenza and adherence to established vaccination protocols.