The fall surge in COVID-19 cases appears to be here.

Cases of COVID-19 are on the rise in most states, and some health experts say it could be a while before that trend comes to an end. "The whole scary part of this is we haven't yet even started flu season," Agnes Kresch, an infectious disease specialist.

The United States is averaging at least 55,000 new, known COVID-19 cases per day. That's more than a 60% hike since mid-September. "I'll be honest with you. I'm extremely worried. And epidemiologists have been predicting a fall spike for a long time," says Dr. Abdul El-Sayed, epidemiologist & public health expert.

As of Sunday, only two states, Missouri and Vermont, are showing at least a 10% drop in new cases.

"When you have people congregating en masse, not wearing masks, not doing physical distancing, barely using hand sanitizer, those are the perfect conditions in which you get the spread of the coronavirus from one person to another," says Dr. Seema Yasmin, former CDC disease detective.

Despite the increase in cases and deaths, Dr. Anthony Fauci, the top infectious disease expert in the nation, does not want to close down the country again. "Put shutdown away and say, 'We're going to use public health measures to help us safely get to where we want to go,'" says Dr. Fauci, director of the National Institute of Allergy and Infectious Diseases.

Some state leaders are pushing new restrictions while vaccine research and testing continues. "Most Americans are going to be getting vaccinated in 2021, and we're probably looking at a March-April, if things go very well, timeframe when let's say a large proportion of American people get access to vaccines," says Dr. Ashish Jha, dean at Brown University School of Public Health.