What can we expect from a winter COVID-19 second wave? No one knows for sure, but there is reason for hope and concern

Since the beginning of the COVID-19 pandemic, experts have warned about the horrors of the 1918 flu. After the first dangerous wave of infections that spring, cities and people relaxed their efforts to contain the virus and it came roaring back in the fall and winter, killing far more people.

So far, COVID-19 hasn't behaved the same way. There was no summer break, and we're not seeing the ebb and flow that characterized the 1918 outbreak. It's been more like a forest fire spiking in one area while dying down in another.

But for months, public health officials have predicted one comparison would stand: We'd have a terrible winter.

The fear is that cases will rise as more people spend more time indoors, get ever more tired of public health measures, travel for the holidays, and struggle with conflicting messages from national and local leaders.

No one really knows what the next few months will bring. But as COVID-19 cases rise in 39 of 50 states, there are a few clues about what's likely to happen, both good and bad.

Hopeful signs

First, the good news.

A coming approach to testing, with lots of inexpensive, readily available, fast tests could transform daily lives, enabling people to do the kinds of things they've only been able to dream about for the past eight months.

Some colleges already are showing they can keep students safe by adding regular testing to mask-wearing and social distancing. Airlines are starting to test all passengers on some flights – because who wouldn't feel safer and be more likely to travel if they knew the person next to them wasn't infected?

Many other activities, like meetings, dental appointments, gym visits and weddings would start to feel reasonable again if everyone could be tested on the way in.

Of course, testing alone isn't enough, as President Donald Trump's recent infection shows. A "superspreader" event apparently occurred at the White House after politicians there relied solely on testing to protect against infection.

Tests have to be combined with other public health measures, including wearing masks and tracing the interactions of anyone who tests positive to make sure anyone they exposed doesn't pass on the virus, said Pınar Keskinocak, a professor at the Georgia Institute of Technology and president of the Institute for Operations Research and the Management Sciences, an international association for professionals in operations research and analytics.

"If you can use the triple action together, testing tracing and isolation, that is going to help a lot" to keep down infections, Keskinocak said.

Although rapid, cheap, easily administered tests aren't yet widely available, they should be in coming months, with the first of 150 million tests funded by the government being shipped this month, and other rapid tests likely to become available by the end of the year.

At least one vaccine also is likely to win preliminary approval by the end of the year, with enough doses first to protect health care workers and then the most vulnerable elderly. It will probably be well into next year, officials have said, before enough people can be vaccinated to provide widespread protection.

Danger signs

The bad news: We can't let up yet.

"Things are likely to get bad in the winter if what we continue to do is relax measures in places where COVID-19 cases are high or increasing," said Samuel Scarpino, an assistant professor at Northeastern University in Boston, where he directs the school's Emergent Epidemics Lab.

Scarpino is worried, for instance, about Massachusetts Gov. Charlie Baker allowing large groups to eat in at restaurants again, which research suggests will enable "super-spreader" events, passing the virus around to a number of others. Massachusetts, like many states, has seen a recent uptick in cases, so now is not the time to loosen restrictions, Scarpino said.

Shruti Mehta, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, said she worries most about the public getting less vigilant. She leads regular surveys about public attitudes toward COVID-19, and each one shows people a little more complacent than the last, she said.

She's also anxious about gatherings around the holidays. Cases have spiked after every long weekend this year, she said, and "Thanksgiving is the mother of all holidays" in terms of travel. People will cram into airplanes and dining rooms, she said, potentially passing on the virus.

Seasonal activity

Dr. Michael Mina, an epidemiologist at the Harvard T.H. Chan School of Public Health, said people tend to forget one crucial fact about coronaviruses like the one that causes COVID-19: They're seasonal.

The drop in COVID-19 cases in August and most of September might have been a seasonal benefit, Mina said.

He's furious that more hasn't been done to avoid what he sees as a dire future.

"We have essentially done nothing since April to actively as a country get a system in place to help it not spread this winter," he said.

Mina said he's not sure exactly when the virus that causes COVID-19 will peak – other coronaviruses spike at different times. But whether in late October or late December, he said, "I expect that we will see a sharp escalation very soon and it will cause us once again to have to shut things down."

"If we think we're going to get through this winter without a seasonal upswing, probably a massive upswing in cases, we're mistaken," he added.

How will we know when it's getting worse?

Barry Bloom, an immunologist at Harvard, said that with COVID, it can be hard to know exactly what's happening as it unfolds.

"What you see now is not what's really there. You have to be able to anticipate what's coming," he said. It takes at least two to three weeks for someone who catches COVID-19 to require hospitalization, so measures like the number of people needing care describe who got infected a few weeks ago, not today.

Bloom said he'd like to see the existing national influenza surveillance network expanded to look at all respiratory viruses. Hopefully, he said, that would offer an early warning sign of where infections are starting to rise.

Another early indicator: sewage. The University of Arizona, for instance, tracks its campus output to look for the virus that causes COVID-19.

In New Haven, Connecticut, genetic material from the virus started to increase up to two days before positive COVID-19 tests revealed a growing infection rate, according to a study this month in Nature Biotechnology. The sludge data were 1-4 days ahead of hospital admissions and – because of delays in getting test results – 6-8 days ahead of people realizing they were infected.

That kind of early information can help public officials make decisions about whether to loosen or tighten public health restrictions, Bloom said.

So, how to make it through?

The predictions are depressing, public health officials concede. But it is possible to remain safe during COVID-19 outbreaks through measures like masks, social distancing and frequent handwashing. Even eyeglasses can provide some protection to prevent viral particles from getting into the body.

So, put on that mask and prepare for a long, hug-free winter.

"What we see in the coming months," Keskinocak said, "really will depend on what people do individually, as a family, as a community."

Contact Karen Weintraub at kweintraub@usatoday.com and Elizabeth Weise at eweise@usatoday.com

Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.

This article originally appeared on USA TODAY: COVID winter: Second wave may be bad, experts warn continued vigilance