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About this tool
Find your best annual flu vaccination window by hemisphere, with the date protection starts, travel deadlines and child second-dose timing.
This planner turns the standing seasonal influenza guidance into two dates: when to book your annual flu vaccination, and the day protection actually starts, which is about 14 days after the injection. It uses the northern hemisphere window of September to October (aim to be done by the end of October), the southern hemisphere window of April to May, and the year-round pattern in the tropics, then adjusts for upcoming travel and for children under 9 who need two priming doses 28 days apart.
Open Flu Shot Reminder Planner on AltFTool — it loads instantly in your browser.
Add your input to the workspace.
Adjust the options until the result looks right.
Copy or download the output and put it to work.
Different windows for northern, southern and equatorial seasons.
Not just the appointment, but when the vaccine is working.
Pulls the date earlier for trips and schedules the 28-day second dose.
In the northern hemisphere, September or October — CDC advice is to be vaccinated by the end of October, before flu activity picks up in November. In the southern hemisphere the equivalent window is April to May, ahead of the June-August peak. Vaccinating much earlier than that can mean protection wanes before the peak.
About two weeks. Protective antibody levels take roughly 14 days to develop after the injection, which is why a shot given the day before a trip or an outbreak does not protect you during that fortnight.
No. Vaccination is recommended for as long as influenza viruses are circulating, which in the northern hemisphere usually means through to May, and flu activity often peaks in February. A late dose gives less coverage across the season than an October one but is still better than none.
Children aged 6 months through 8 years who have never had an influenza vaccine need two doses at least 4 weeks apart, because a single dose does not prime an immune system with no prior exposure well enough. In later seasons a single annual dose is enough. Confirm the schedule with your child's doctor or nurse.