As Americans brace for 2nd wave of COVID-19, here's why experts predict more infections but lower death rate

As the United States braces itself for a likely "second wave" of COVID-19 this fall, many experts are anticipating a spike in cases -- but some say that may not translate into an equally dramatic spike in deaths.

A lot has changed since the pandemic first hit the U.S. earlier this year, when the nation's hospitals were overwhelmed with patients suffering a new, mysterious illness. Fast forward to September, and the pandemic is still surging out of control in many parts of the country, but relatively speaking, fewer patients are dying from the virus.

Now, experts are pointing to several factors to explain why COVID-19 has become, in effect, a slightly less deadly illness: still far deadlier than the flu, but not as lethal as it was in those early days.

Six months into the pandemic, doctors now have more success treating patients with the novel coronavirus -- especially those with severe symptoms -- than they did at the beginning of the year. Adults that are older and more vulnerable to illness are staying home, as the virus is now infecting a greater number of younger people who are less likely to succumb to illness.

"In terms of absolute numbers, we are learning much more about how to treat patients with serious complications compared to at the start of the pandemic," said Dr. John Brownstein, a Harvard Medical School professor and ABC News contributor. "Now that we know more effective protocols and treatments, the number of deaths will likely go down."

There are various techniques and treatments coming into the scene that are helping medical teams move forward.

Dexamethasone, a steroid treatment mainly used to cure lung inflammation, is seeing positive results in COVID-19 patients, especially when used early on.

The Food and Drug Administration has broadened emergency use authorization for an antiviral drug called remdesivir. Studies show the antiviral therapy used to treat hospitalized patients with the virus decreases mortality rates.

In addition to the use of new drugs, doctors also have learned practical tips that can help patients survive. A tactic called "proning" -- simply flipping a patient on their stomach -- lets oxygen run more effectively through the body.

Also, doctors have learned to hold off on placing patients on ventilators right away because they've found less invasive ways to help patients with labored breathing get enough air, according to experts, who also said doctors are now working to assess patients earlier to try to make interventions sooner.

And as doctors continue learning how to save patients in the hospital, public health experts continue learning more effective habits to avoid the spread of COVID-19, especially in vulnerable populations.

"When it comes to infections, there are prevention techniques we know work, including physical distancing, social distancing, mask wearing and mindful hygiene/hand washing," said Dr. Jay Bhatt, an ABC News contributor and former chief medical officer of the American Hospital Association.

"With wider availability of PPE and acceptance of the new normal, we now have supplies to protect people," said Bhatt. "The work by health care deliveries and health systems is key, with strategies and protocols put in place for our health and safety. These behaviors, in turn, help drive down the numbers of deaths."

The change in seasons will be important to pay attention to as we keep an eye on infections with people staying indoors come the fall and winter.

"Outdoors there is lower risk for transmission from the greater air movement. The odds of getting sick are lower when you are outside compared to confined spaces like elevators and living in close proximity," said Dr. Simone Wildes, an infectious disease physician at South Shore Health in Massachusetts. "Being in crowded spaces, you are much more likely to spread the virus."

Doctors encourage low-risk people to enjoy the outdoors, while still paying attention to standard protocols and social distancing. "As the fall approaches, you have drier conditions. More people are spending more time indoors, so generally the virus is more efficient," explained Brownstein.

The average age of those infected with coronavirus has declined over the last several months.

We are seeing spikes with younger and less vulnerable populations. Furthermore, special attention has been paid to older populations by sealing off high-risk settings where we see people more susceptible to illness -- like nursing homes.

"Early on, we really focused on the elderly 65+ years of age with underlying conditions," said Wildes. "As we reopen, we see a lot of young people getting the virus. Most young people do not have underlying conditions, so they do a lot better than the older, more susceptible populations."

Again, the time of year plays a role in this shift. "Percentage wise, a rise in cases is being triggered amongst the younger population, because upon returning to school, they are not practicing the same level of social distancing and mask wearing," said Brownstein.

Younger, healthy people are venturing out and are less likely to die from the virus.

But for many public health experts, the relatively lower death rate moving into the fall is the only bright spot in an otherwise gloomy forecast. The Centers for Disease Control is now predicting that within the next four weeks, the virus will have killed between 3,300 and 7,500 Americans, and infected 150,000 to 360,000 others.

This trend is already playing out in North Carolina, where college campuses reopened last month with in-person classes, and at least 3,000 students have tested positive for COVID-19. UNC at Chapel Hill, NC State University and East Carolina University are three schools in particular that have experienced overwhelming spikes.

A major goal from a medical standpoint is to minimize deaths, and as we approach the fall, a big concern coming into play is the intersection between coronavirus and the flu. Wildes stressed that doctors are encouraging everyone to get the flu vaccine to boost their chances of staying healthy this winter. Experts are also encouraging everyone to continue following social distancing measures to prevent as many COVID-19 infections as possible.