New York's governor has declared a health emergency over a flu epidemic that has hit more than 19,000 people, and in an exceptional measure cleared pharmacists to immunize infants and children.

To try to curb the spread of the potentially lethal virus, Andrew Cuomo said it was critical to suspend, for the next 30 days, a legal restriction that only allows New York pharmacists to administer flu vaccines to patients 18 or older. His statement on Saturday came amid a nationwide epidemic expected to last several weeks.

We are experiencing the worst flu season since at least 2009, and influenza activity in New York State is widespread, with cases reported in all 57 counties and all five boroughs of New York City," said Cuomo.Meanwhile, Massachusetts has had 18 flu deaths so far this season, according to the state Department of Public Health.