NEW YORK - When coronavirus hit New York City, doctors had to learn on the fly how to treat a never-before-seen illness. In the weeks since, they’ve become accustomed to constantly comparing notes and making adjustments as they go.

There have been no breakthroughs, but there have been lessons learned.

“We know how to handle this. I don't want to say we made big mistakes before, or anything to that effect,” said Dr. Thomas McGinn, Deputy Physician-In-Chief at Northwell Health. “I just think we're comfortable with it. Our protocols are in place. Some early use of medications that were standardized by everybody have now come back, and we've said, ‘Don't use those.’"

Early on, doctors discovered simply turning patients onto their stomachs could improve oxygen flow, part of an effort to keep them off ventilators. And doctors upped the use of blood thinners after discovering widespread blood clotting.

"We're actually doing a randomized trial now looking at different doses and techniques of these blood thinners,” said McGinn. “And we think that's a key element to saving these people."

Doctors have also looked to a host of drugs that could either help fight off the virus or manage the body's immune response; many are still undergoing study. That includes hydroxychloroquine, an anti-malarial drug championed by President Trump that hospitals have now moved away from.

"None of these drugs are a home run,” said Dr. Charles Powell, chief of the Division of Pulmonary, Critical Care and Sleep Medicine at the Mount Sinai Health System and CEO of the Mount Sinai-National Jewish Health Respiratory Institute. “None of these drugs are a cure for COVID."

Even one promising drug, Remdesivir, has only been shown to shorten hospital stays, not necessarily change outcomes.

"Is it possible that these drugs are going to allow some patients to survive who otherwise wouldn't survive? I'd say the answer is probably yes,” said Powell. “But that has to be proven by the data from the trials that are in place right now."

Some hospitals are also experimenting with new treatments, like convalescent blood plasma taken from recovered patients who've developed immunity, and new stem cell therapy. And any COVID patient now arriving at a hospital will find it far less crowded than a month ago.

"You could guess that it's better to be a COVID patient coming in when there's only 40 other patients at the hospital, and the hospital's not overwhelmed,” said Dr. David Charytan, Director of Nephrology Division, NYU School of Medicine. “That's probably a better thing."