Feature

Three COVID scenarios that could spell trouble for the fall


 

As the United States enters a third fall with COVID-19, the virus for many is seemingly gone – or at least out of mind. But for those keeping watch, it is far from forgotten as deaths and infections continue to mount at a lower but steady pace.

What does that mean for the upcoming months? Experts predict different scenarios, some more dire than others – with one more encouraging.

In the United States, more than 300 people still die every day from COVID and more than 44,000 new daily cases are reported, according to the Centers for Disease Control and Prevention.

But progress is undeniable. The stark daily death tolls of 2020 have plummeted. Vaccines and treatments have dramatically reduced severe illness, and mask requirements have mostly turned to personal preference.

Epidemiologists and other medical experts laud the progress, but as they look at the maps and the numbers, they see several scenarios ahead that signal a coming wave of disease, among them more-resistant variants coupled with waning immunity, the potential for a “twindemic” with a flu/COVID onslaught, and underuse of lifesaving vaccines and treatments.

Variants loom/waning immunity

Omicron variant BA.5 still makes up about 80% of infections in the United States, followed by BA4.6, according to the CDC, but other subvariants are emerging and showing signs of resistance to current antiviral treatments.

Eric Topol, MD, founder and director of the Scripps Research Translational Institute in San Diego, said about COVID this fall: “There will be another wave, magnitude unknown.”

He said subvariants XBB and BQ.1.1 “have extreme levels of immune evasion and both could pose a challenge,” explaining that XBB is more likely to cause trouble than BQ.1.1 because it is even more resistant to natural or vaccine-induced immunity.

Dr. Topol pointed to new research on those variants in a preprint posted on bioRxiv. The authors’ conclusion: “These results suggest that current herd immunity and BA.5 vaccine boosters may not provide sufficiently broad protection against infection.”

Another variant to watch, some experts say, is Omicron subvariant BA.2.75.2, which has shown resistance to antiviral treatments. It is also growing at a rather alarming rate, says Michael Sweat, PhD, director of the Medical University of South Carolina Center for Global Health in Charleston. That subvariant currently makes up under 2% of U.S. cases but has spread to at least 55 countries and 43 U.S. states after first appearing at the end of last year globally and in mid-June in the United States.

A non–peer-reviewed preprint study from Sweden found that the variant in blood samples was neutralized on average “at titers approximately 6.5 times lower than BA.5, making BA.2.75.2 the most [neutralization-resistant] variant evaluated to date.”

Katelyn Jetelina, PhD, assistant professor in the department of epidemiology at University of Texas Health Science Center, Houston, said in an interview the U.S. waves often follow Europe’s, and Europe has seen a recent spike in cases and hospitalizations not related to Omicron subvariants, but to weather changes, waning immunity, and changes in behavior.

The World Health Organization reported on Oct. 5 that, while cases were down in every other region of the world, Europe’s numbers stand out, with an 8% increase in cases from the week before.

Dr. Jetelina cited events such as Oktoberfest in Germany, which ended in the first week of October after drawing nearly 6 million people over 2 weeks, as a potential contributor, and people heading indoors as weather patterns change in Europe.

Ali Mokdad, PhD, chief strategy officer for population health at the University of Washington, Seattle, said in an interview he is less worried about the documented variants we know about than he is about the potential for a new immune-escape variety yet to emerge.

“Right now we know the Chinese are gearing up to open up the country, and because they have low immunity and little infection, we expect in China there will be a lot of spread of Omicron,” he said. “It’s possible because of the number of infections we could see a new variant.”

Dr. Mokdad said waning immunity could also leave populations vulnerable to variants.

“Even if you get infected, after about 5 months, you’re susceptible again. Remember, most of the infections from Omicron happened in January or February 2022, and we had two waves after that,” he said.

The new bivalent vaccines tweaked to target some Omicron variants will help, Dr. Mokdad said, but he noted, “people are very reluctant to take it.”

Jennifer Nuzzo, DrPH, professor of epidemiology and director of the Pandemic Center at Brown University, Providence, R.I., worries that in the United States we have less ability this year to track variants as funding has receded for testing kits and testing sites. Most people are testing at home – which doesn’t show up in the numbers – and the United States is relying more on other countries’ data to spot trends.

“I think we’re just going to have less visibility into the circulation of this virus,” she said in an interview.

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