The city will soon require some 150,000 children who go to preschool or day care to get flu shots.
The Board of Health voted Wednesday for the mandatory vaccine for children under 6, but parents may still opt out for medical or religious reasons.
The initiative takes effect in 30 days.
Dr. Jay Varma, deputy commissioner for disease control, said the vaccine could save lives, noting that four flu-related deaths were reported in the city in the past year. He said vaccinations could keep as many as 20,000 kids from getting sick.
Each flu season, an estimated 15 to 40 percent of city kids are affected by the disease, and younger children are at particular risk, officials said.
“Young children have a high risk of developing severe complications from influenza,” the board said. “One-third of children under five in New York City do not receive an annual influenza vaccination, even though the vaccine safely and effectively protects them.”
Critics said the city’s new policy leaves parents with little say.
“They basically rubber-stamped it with very little public participation,” said John Gilmore, the executive director of the New York-based Autism Action Network.
“To force someone to modify their children’s body is very, very serious.”
Varma countered that the vaccine is safe, and that parents concerned about substances in vaccines may choose from several other versions of the shot.