Health professionals say the vaccine will prevent about 62 percent of the people who get it from getting the flu while the rest will have a milder case of it. A vaccine takes two weeks to fully kick in.
People can decrease their odds of getting the flu by washing their hands frequently and avoiding touching the eyes, nose and mouth. Because viruses can be spread by the hands as well as the air, health professionals recommend coughing into an elbow rather than the hand and staying home to treat the flu rather than going to work and spreading the illness.
Flu season generally peaks in January and February and can linger through March. This year's severe flu season follows the mildest ever recorded last year.
On Saturday, New York City Public Advocate Bill de Blasio joined health professionals and parents at a news conference calling for immediate passage of paid sick leave legislation stalled in the City Council.
He said more than a million New Yorkers lack even a single paid sick day, forcing them between going to work sick and spread the flu or staying home and losing a day's pay.