A nurse prepares a flu shot at Huntington Village Pediatrics in...

A nurse prepares a flu shot at Huntington Village Pediatrics in Huntington in December 2021. Credit: Newsday / Steve Pfost

An unusual influenza season, which featured two peaks in less than six months, hit Long Island especially hard this year, according to recent data released by the state.

Nassau had 13,698 lab-confirmed cases this flu season, and Suffolk had 14,070, for a total of 27,768. This number eclipsed any of the five boroughs of New York City where the highest count came from Brooklyn with 11,693 cases.

This comes after a season of relatively low flu activity in 2020-21, mainly due to COVID-19 pandemic shutdowns and restrictions.

The state starts collecting data at the start of the season in October and generally issues its final count at the end of May. But due to the high number of cases in recent weeks, state officials said Wednesday they will continue the surveillance season until flu activity has decreased.


  • Health officials believe we may be at the end of an unusual flu season, which had peaks in December and April/May. 
  • So far there are more than 27,700 lab-confirmed cases of influenza on Long Island since October 2021, the highest number for a season since 2009-10, the earliest data available. 
  • Infectious disease experts say the surge in cases could be because fewer people received flu shots this season, and because masks and other COVID-19 precautions were largely dropped and more people were tested for respiratory viruses because of the pandemic.

So far, there have been 115,098 lab confirmed cases across the state this year, with the peak of cases coming in both December 2021 and again in April and May, 2022. There were 4,921 lab-confirmed cases in 2020-21, 157,758 in 2019-20 and 107,805 in 2018-19, according to the state.

The late-season surge prompted state health officials to send an advisory to public and private schools in the state in mid-May. They noted that influenza A (H3) — which has been the dominant virus circulating this season — can “cause disproportionately more illness among young children and older adults.” Almost 60% of lab-confirmed cases, at the time of the advisory, were found in people 17 years of age and younger.

Experts pointed to several reasons for the so-called “bimodal” distribution of flu activity but said they doubted the rates of cases on Long Island were significantly different from other places or indicated a problem specific to the region.

According to the Centers for Disease Control and Prevention, there was over an 11% drop in the number of people 18 and over who received the flu vaccine as of April 2022 compared with that same time period as of April 2021 across the United States. 

“Along with the push for COVID vaccines, many people have neglected other vaccines and flu was one of them,” said Dr. Bruce Farber, chief of public health and epidemiology at Northwell Health. “I think we had an undervaccinated population.”

Farber also said the wearing of masks and other mitigation efforts to battle COVID-19 also helped in slashing dramatically the number of flu cases over the last two years.

“So now it’s back and we have several years of people who have had very little to no flu exposure at all, making them probably a little bit more vulnerable because immunity is population based and builds up over time,” Farber said

Dr. Aaron Glatt, chairman of medicine and chief of infectious diseases at Mount Sinai South Nassau hospital pointed out every flu season is different and decreased COVID-19 precautions is one factor.

“There are several possibilities as to why flu is still being diagnosed, and certainly, increased testing is part of the answer,” he said.

Many people who were tested for COVID-19 at their doctor’s offices and other facilities received a Respiratory Viral Panel PCR test, which checks for several illnesses including adenovirus, rhinovirus and influenza.

“Depending upon the approach and the availability of RVPs, you can get a lot more cases of flu and other viruses or less depending upon whether they are being looked for,” Farber said.

He said that could be one of the reasons there were more lab-confirmed cases on Long Island. Figures from the state show 2021-22 had the highest number of lab-confirmed cases on Long Island going back to at least the 2009-10 season, the earliest data available. 

“There’s no question there was more flu but the reasons for the late surge of flu are not completely clear,” Farber said. “I think it will rapidly go away over the next several months.”

Farber said development of a combination flu and COVID-19 vaccine could result in more people getting the important shots.

“People are clearly fatigued with the vaccines,” he said. “But that doesn’t mean we don’t need them. The easier we can make it, the better the compliance.”

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