Across the United States, kids are prepping for back-to-school, or are already in classrooms, and parents are buckling up for another pandemic school year. Like me, many are trying to get a handle on what COVID-19 precautions to take. Updated guidance released last week by the U.S. Centers for Disease Control and Prevention hasn’t exactly helped. It may have made dealing with back-to-school more confusing — and could even spur new outbreaks.

Last November, my fifth grader had to quarantine at home for 10 days after a close contact tested positive. Now, the CDC has nixed the quarantine recommendation for people exposed to COVID-19. Today, our situation could look something like this: My COVID-exposed daughter would mask for 10 days, test on day five, and remain in school the whole time — only the infected child would isolate. That child would stay home for at least five days after a positive test. Then, if the child is fever-free and symptoms are improving, according to the new guidance, they could pop on a mask and hightail it back to class — no testing needed.
That advice could mean more COVID-19 in classrooms. Scientists have shown that people can remain infectious after day five. So without testing for COVID-19, students and teachers won’t know if they’re bringing the disease back to school.

On the same day the CDC’s guidance came out, the U.S. Food and Drug Administration added yet another wrinkle. If you think you’ve been exposed to COVID-19 but test negative with an at-home COVID-19 antigen test, the FDA now recommends testing again … and again. Repeat testing over time cuts the chances you’ll miss an infection and unknowingly spread the virus, the FDA advised on August 11.

It’s hard to say how that advice jibes with the CDC’s new, more-relaxed guidelines. Even the agency has said its public guidance during the pandemic has been “confusing and overwhelming,” the New York Times reports. CDC director Rochelle Walensky is now planning a shake-up that could include restructuring the communications office as well as relying more on preliminary studies rather tha
The CDC’s new guidance has sparked a range of reactions, many negative, among scientists, doctors, parents and teachers. In an informal Twitter poll of Science News followers, roughly 80 percent of the 353 respondents reported that the new CDC guidance made them feel confused, worried or angry and/or exasperated.

Now, it’s up to local school districts to decide what COVID-19 measures to take. “Just because guidance has changed does not mean COVID is gone,” Becky Pringle, president of the National Education Association labor union, said in a statement. Not by a long shot. The United States is currently averaging nearly 500 daily coronavirus deaths and more than 100,000 new cases a day, an almost certain undercount.

As my own children gear up for school, I wonder about COVID-19’s constantly shifting landscape. Like other families with school-aged children, we’ve bounced from virtual school to in-person mask mandates to mask-optional recommendations. And we still don’t know our district’s plans for the upcoming year. School starts in about a week.

There is reason for hope, though: We know what measures can slow COVID-19’s spread in schools. Masking is a big one. A preliminary study posted August 9 linked lifting school mask mandates in Boston-area K–12 schools with a rise in cases among students and staff. At Boston University, mandatory masking plus a vaccine mandate seemed to keep the virus in check in classrooms, scientists reported August 5 in JAMA Network Open. Testing can help, too. A computer analysis from England suggests that regularly rapid testing students can curb classroom transmission, scientists report August 10 in the Royal Society Open Science.
But knowing what works is not the same as actually employing evidence-based measures in the classroom, says Anne Sosin, a public health researcher at Dartmouth College whose research focuses on COVID-19 and rural health equity. She has studied how pandemic policies have impacted schools in northern New England. “I worry that we simply have not seen the political leadership to ensure that all children and educators can safely participate in school.”

I spoke with Sosin about the CDC’s new guidance, and what kids and parents might expect heading into the new school year. Our conversation has been edited for length and clarity.

SN: What do you think of the updated guidance?

Sosin: I was very disappointed that the CDC did not adopt a test-to-exit-isolation recommendation.

What we’re going to see in schools are infected students and educators returning after five days still positive for COVID-19. Multiple studies have demonstrated that most people are infectious beyond five days. Not only is it highly likely that they’ll be seeding outbreaks. They’ll also be putting high-risk members of school communities in danger.

SN: What could the guidance mean for vulnerable kids?

Sosin: I think that vulnerable people are going to be in a very precarious situation. The guidance mentions the need to ensure protections for immunocompromised and other high-risk people but there’s a problem of implementation. Will schools actually implement those protections?

SN: Do scientists have a good handle on what protections can help?

Sosin: Definitely. We have really strong evidence showing that when layered mitigation strategies are in place, we can almost eliminate transmission in school settings. That means that we should have upgraded ventilation, lunchroom strategies [like taking kids outside to eat] and testing. And I continue to think that data-driven mask policies have a role to play. Not masking forever, but masking at times when we see an uptick in transmission.

SN: How could the new guidance affect different communities across the United States?

Sosin: Different communities have not only been impacted in dramatically different ways, but they’re also on unequal footing at this stage of the pandemic.

[If we compare white communities with communities of color], we see disparities in vaccination coverage and caregiver loss. Some communities have suffered enormous losses while others have really been untouched. Black children have lost caregivers at more than two times the rate of white children. For Indigenous children, the rate is 4.5 times as high. Those are sharp disparities.

Communities of color also have less access to testing, treatment and health care. I worry that if we don’t have a renewed focus on equity, then we’re just going to see an exacerbation of disparities that have existed throughout the pandemic.

SN: What advice do you have for parents as they head into the new school year?

Sosin: We all want as normal a school year as possible. Masking should be one of the tools we’re ready to employ to keep our kids in the classroom. In addition, we should be advocating that our schools invest in ventilation. Vaccination also represents a critical piece of the strategy.

We see such abysmal vaccination coverage among children. Less than 1 in 3 kids ages 5 to 11 are fully vaccinated. I think many parents no longer see it as important — there’s been this narrative that the pandemic is over. We need clear messaging that vaccination remains an important tool.

Now is a great time to plan back-to-school campaigns to vaccinate kids and to begin to prepare for the arrival of omicron-specific boosters in the fall.

Archaeologist Peter Bellwood’s academic odyssey wended from England to teaching posts halfway around the world, first in New Zealand and then in Australia. For more than 50 years, he has studied how humans settled islands from Southeast Asia to Polynesia.

So it’s fitting that his new book, a plain-English summary of what’s known and what’s not about the evolution of humans and our ancestors, emphasizes movement. In The Five-Million-Year Odyssey, Bellwood examines a parade of species in the human evolutionary family — he collectively refers to them as hominins, whereas some others (including Science News) use the term hominids (SN: 9/15/21) — and tracks their migrations across land and sea. He marshals evidence indicating that hominids in motion continually shifted the direction of biological and cultural evolution.
Throughout his tour, Bellwood presents his own take on contested topics. But when available evidence leaves a debate unresolved, he says so. Consider the earliest hominids. Species from at least 4.4 million years ago or more whose hominid status is controversial, such as Ardipithecus ramidus, get a brief mention. Bellwood renders no verdict on whether those finds come from early hominids or ancient apes. He focuses instead on African australopithecines, a set of upright but partly apelike species thought to have included populations that evolved into members of our own genus, Homo, around 2.5 million to 3 million years ago. Bellwood hammers home the point that stone-tool making by the last australopithecines, the first Homo groups or both contributed to the evolution of bigger brains in our ancestors.

The action speeds up when Homo erectus becomes the first known hominid to leave Africa, roughly 2 million years ago. Questions remain, Bellwood writes, about how many such migrations occurred and whether this humanlike species reached distant islands such as Flores in Indonesia, perhaps giving rise to small hominids called hobbits, or Homo floresiensis (SN: 3/30/16). What’s clear is that H. erectus groups journeyed across mainland Asia and at least as far as the Indonesian island of Java.

Intercontinental migrations flourished after Homo sapiens debuted, around 300,000 years ago in Africa. Bellwood regards H. sapiens, Neandertals and Denisovans as distinct species that interbred in certain parts of Asia and Europe. He suggests that Neandertals disappeared around 40,000 years ago as they mated with members of more numerous H. sapiens populations, leaving a genetic legacy in people today. But he does not address an opposing argument that different Homo populations at this time, including Neandertals, were too closely related to have been separate species and that it was intermittent mating among these mobile groups that drove the evolution of present-day humans (SN: 6/5/21).

Bellwood gives considerable attention to the rise of food production and domestication in Europe and Asia after around 9,000 years ago. He builds on an argument, derived from his 2004 book First Farmers, that expanding populations of early cultivators migrated to new lands in such great numbers that they spread major language families with them. For instance, farmers in what’s now Turkey spread Indo-European languages into much of Europe sometime after roughly 8,000 years ago, Bellwood contends.

He rejects a recent alternative proposal, based on ancient DNA evidence, that horse-riding herders of Central Asia’s Yamnaya culture brought their traditions and Indo-European tongues to Europe around 5,000 years ago (SN: 11/15/17). Too few Yamnaya immigrated to impose a new language on European communities, Bellwood says. Similarly, he argues, ancient Eurasian conquerors, from Alexander the Great to Roman emperors, couldn’t get speakers of regional languages to adopt new ones spoken by their outnumbered military masters.

Bellwood rounds out his evolutionary odyssey with a reconstruction of how early agricultural populations expanded through East Asia and beyond, to Australia, a string of Pacific islands and the Americas. Between about 4,000 and 750 years ago, for instance, sea-faring farmers spread Austronesian languages from southern China and Taiwan to Madagascar in the west and Polynesia in the east. Precisely how they accomplished that remarkable feat remains a puzzle.

Disappointingly, Bellwood doesn’t weigh in on a recent archaeological argument that ancient societies were more flexible and complex than long assumed (SN: 11/9/21). On the plus side, his evolutionary odyssey moves along at a brisk pace and, like our ancestors, covers a lot of ground.

Sometimes a photo is literally a matter of life, death — and zombies.

This haunting image, winner of the 2022 BMC Ecology and Evolution photography competition, certainly fits that description. It captures the fruiting bodies of a parasitic fungus, emerging from the lifeless body of an infected fly in the Peruvian rainforest.

The fungus-infested fly was one of many images submitted to the contest from all over the world, aiming to showcase the beauty of the natural world and the challenges it faces. The journal revealed the winners August 18.
Roberto García-Roa, a conservation photographer and evolutionary biologist at the University of Valencia in Spain, took the winning photo while visiting the Tambopata National Reserve, a protected habitat in the Amazon.

The fungus erupting from the fly belongs to the genus Ophiocordyceps, a diverse collection of parasitic fungi known as “zombie fungi,” due to their ability to infect insects and control their minds (SN: 7/17/19).

“There is still much to unravel about the diversity of these fungi as it is likely that each insect species infected succumbs to its own, specialized fungus,” says Charissa de Bekker, an expert in parasitic fungi at Utrecht University in the Netherlands.

First, spores of the fungus land on the ill-fated fly. So begins the manipulative endgame. The spores infiltrate the fly’s exoskeleton before infecting its body and eventually hijacking its mind. Once in control, the fungus uses its new powers of locomotion to relocate to a microclimate more suitable to its own growth — somewhere with the right temperature, light and moisture.

Fungus and fly then bide their time until the fly dies, becoming a food source for the fungus to consume. Fruiting bodies work their way out of the fly, filled with spores that are released into the air to continue the macabre cycle in a new, unsuspecting host. It is a “conquest shaped by thousands of years of evolution,” García-Roa said in a statement announcing the winners.

Research into the molecular aspects of fungal mind control is under way, De Bekker says, including in her own lab. “These fungi harbor all sorts of bioactive chemicals that we have yet to characterize and that could have novel medicinal and pest control applications.”