"The flu doesn't care if you're a man or a woman, old or young. It just wants to know if you've been vaccinated or not," he said.
Emergency room visits for the flu have jumped along with reported cases overall. Dr. Dan Wiener, the chairman of emergency medicine at Saint Luke's Roosevelt Hospital, said the increase is stressing capacity at the Manhattan hospital, which like several other facilities was already taking on a greater role to compensate for hospitals closed or damaged by Superstorm Sandy.
But Wiener said it makes sense to stay out of the emergency room unless you're in a high risk group, like the elderly, or experiencing very serious symptoms like a persistent high fever. "Unless you're in a high risk group, there's not much we can do," he said.
Still, it's a serious illness. The flu has killed two children in the state already this season, and 20 have died nationally. At least 10 residents of long-term care facilities like nursing homes have died in New York City's five boroughs. City nursing homes are seeing an epidemic, Wiener said, noting that people who are already ill or weak before contracting the flu are more vulnerable.
Hospitals are trying to separate patients who appear to have the flu in emergency rooms and if they're admitted, but so far none in New York appear to be taking the drastic step of screening visitors, which has been reported in Boston, where Mayor Thomas Menino declared a public health emergency due to the flu on Wednesday.
Doctors have mixed opinions about whether this year's flu is more severe than past years, or if it just spread faster. But all agree that for those who haven't been sick yet, it makes sense to get a flu vaccine. Each year's vaccine is designed to combat a different strain of the virus, and this year's shot was successful in targeting the most prevalent strain.
The vaccine will help about 70 percent of people who get it avoid the illness altogether, and the remaining 30 percent will likely have a milder case.
And Steier said don't worry about getting the flu from the shot itself. "That's not possible," he said. "It's basically a killed virus."
Associated Press videojournalist Joseph Frederick contributed to this report.