Are annual flu shots really necessary?

Yes, for most people. Circulating influenza strains change yearly and vaccine-induced immunity wanes over months. Vaccination cuts risk of severe illness and hospitalisation, and is especially important for those over 65, pregnant women, children, and people with chronic disease.

The shot does not prevent every infection, but it substantially reduces severity, hospitalisation and death. Judging it by whether you still catch a mild illness misses the main benefit.

In India, vaccination before the onset of the monsoon and again before winter is commonly advised, since influenza has two seasonal peaks in much of the country.