Prevention and Control of Seasonal Influenza with Vaccines
Timing of Vaccination
In general, health-care providers should begin offering vaccination soon after vaccine becomes available and, if possible, by October.
All children aged 6 months through 8 years who are recommended for 2 doses should receive their first dose as soon as possible after vaccine becomes available; these children should receive the second dose ≥4 weeks later.
This practice increases the opportunity for both doses to be administered before or shortly after the onset of influenza activity. To avoid missed opportunities for vaccination, providers should offer vaccination during routine health-care visits or during hospitalizations whenever vaccine is available.
Vaccination efforts should be structured to ensure the vaccination of as many persons as possible before influenza activity in the community begins. In any given year, the optimal time to vaccinate cannot be determined precisely because influenza seasons vary in their timing and duration, and more than one outbreak might occur in a single community in a single year. In the United States, localized outbreaks that indicate the start of seasonal influenza activity can occur as early as October. However, in >80% of influenza seasons since 1976, peak influenza activity (which often is close to the midpoint of influenza activity for the season) has not occurred until January or later, and in >60% of seasons, the peak was in February or later.