NEW YORK (PIX11) — Infectious disease experts are warning of a possible “twindemic” of COVID-19 and flu cases this fall and winter.

Dr. Waleed Javaid, the Director of Infection Prevention and Control at Mt. Sinai Downtown, told PIX11 News on Tuesday they’re already seeing the beginnings of a winter COVID-19 surge.

“We see the numbers are slowly trickling upwards,” he said.

Dr. Javaid said now is the best time to protect yourself with vaccines. He said vaccines generally take 14 days to provide maximum protection, so getting a shot now will ensure coverage over the Thanksgiving holiday.

Javaid also warned an epidemic level of flu cases is possible this winter. 

“We can anticipate a much more severe flu season than before,” said he said.

Dr. Syra Madad, the Senior Director of Systemwide Pathogens Program at NYC Health + Hospitals, the co-circulation creates more opportunities for both viruses to spread and infect people.

Dr. Madad studies preparedness, response, and recovery efforts for infectious disease threats. She strongly recommends protecting yourself with both a COVID-19 booster and a flu shot.

“Respiratory viruses – RSV, seasonal flu, COVID-19 – are starting to bubble up, and so it’s important that you’re aware and you’re cautious,” said Dr. Madad.

Respiratory viruses like RSV, which is currently surging among children in the tri-state area, also pose an added problem this fall and winter. Doctors say our immune systems are just not as prepared to fight these viruses, after two years of staying indoors and wearing masks.

“Immune level in the community is low, there’s no vaccine for RSV … all the children are together [in school],” said Dr. Javaid. “It’s a muncher higher chance they’re getting infected.”