Incredible When Is The Best Time To Get The Flu Shot Ideas . The flu shot’s level of protection against the flu does wane with time — a 2017 study published in the journal clinical infectious diseases (opens in new tab) found that the flu. According to a study, for adults (generally 65 years and older), the time of day they receive their flu vaccine affects how well their body is able to fight off antibody resistance. When Is the Best Time to Get Your Flu Shot? The New York Times from www.nytimes.com The flu shot can still provide protection if you get it later in the season when flu activity peaks, according to the cdc. In uk terms, this means someone who has their jab in september, when the vaccination campaign begins, may have poor protection in february, when the flu season is at. The flu shot’s level of protection against the flu does wane with time — a 2017 study published in the journal clinical infectious diseases (opens in new tab) found that the flu.