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Slow relaxation of COVID-19 rules helps push recurrence back

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Enlarge / Spanish chef Jordi Roca prepares dishes at the “El Celler de Can Roca” restaurant in Girona on June 23, 2020, on the day it reopens after a national lockdown to stop the spread of the novel coronavirus.

Countries like the United States have never really gotten the pandemic under control, while others, like Brazil, haven’t even slowed the pace of infections. But elsewhere, many countries that took dramatic action to limit the spread of COVID-19 have seen the rate of infections plunge, leaving them with the issue of how to successfully emerge from the restrictions they put in place.

One of those countries is Spain, where infections have dropped from a peak of over 9,000 a day in late March to only about 300 a day at present. Two researchers based in Barcelona (Leonardo López and Xavier Rodó) decided to look at different ways Spain could have exited its restrictions while protecting future public health. After building their model, they set it loose on other countries, including the US. Their work lets us test what might happen if the immunity developed in those infected fades over time or the public’s fear of the virus subsides after it’s under control.

Lockdown vs. open up

How did Spain get cases in check? In part, by following the advice of public health experts. On March 29, it placed everyone in non-essential jobs on a strict lockdown. Two weeks later, with cases dropping, restrictions started being eased. But the easing was done cautiously, with a variety of restrictions being kept in place as cases continued to drop. López and Rodó were interested in looking at how this reopening could be handled in a way that most effectively limits future returns of widespread infections.

To do so, they built an epidemiological model that was able to incorporate a variety of distinct factors. The foundation of their work was a standard susceptible–exposed–infectious–recovered model, in which the population is moved among the above groups based on the spread of the virus. That spread is based on what we know of things like the virus’ infectivity, how long people can spread it before and after developing symptoms, and so on.

López and Rodó added some critical features to this model. To begin with, it’s able to handle the fact that some aspects of the virus’ behavior aren’t precisely defined—our estimates of how long people are infective before symptoms appear are a bit rough, to give one example. So the authors added a probabilistic element, where the model could be run multiple times with uncertain values varied around their most likely values. This helps show how robust any result is by highlighting whether it’s sensitive to small changes in things we’re uncertain about.

To address the issue at hand, the researchers included an isolated population, which could not become infected. They acknowledge that this is obviously unrealistic, since some of the people in isolation will undoubtedly become infected. But they argue that it provides a low estimate while avoiding potentially alarmist results.

Finally, they include the ability to have some features of the pandemic and public health response vary over time. These include factors like a fading of the immunity that’s been seen in other coronaviruses. In addition, they allow the degree of compliance with social-distancing rules to vary over time, as fears during periods of high infection will probably boost compliance initially, but fade over time. These factors influence existing pieces of the epidemiological model. For example, the fading of immunity would move people out of the “recovered” pool and back into the “susceptible” group, while fading of social-distancing compliance could be simulated by increasing the rate of new infections.

Finally, and critically for the research question here, the process of ending lockdown could be modeled directly as a time-varying process of moving more people out of the isolated population and into the susceptible one. This let them explore different rates of ending the lockdown, from an immediate, complete elimination of the isolated population to different fractions being removed over time.

Spain and beyond

The researchers started by initializing their model with the actual data from Spain, from the start of the pandemic up to its peak in that country. People were released from the confined group until the pre-pandemic working population of Spain was back in the susceptible group. The researchers modeled various dynamics for this “deconfinement,” ranging from letting everyone out immediately to gradually allowing increasing numbers of people back into the working population. They also varied the length of the lockdown period.

The results are about what you’d expect. The longer the lockdown lasted, the longer it took for a second peak of infections to occur. And a gradual release of the isolated population tended to delay the appearance of the new peak even further. (Spain’s actual policy, which was also simulated, leaves it vulnerable to a a new peak in July, according to this model.) In the case of a 90-day lockdown and a gradual rate of release from isolation, the second wave was delayed to beyond the time scale of their study, which ended in early 2021.

In all cases, however, the number of deaths remained low, as one of the most vulnerable populations—the elderly—was kept in isolation since it wasn’t part of Spain’s pre-pandemic work force. The impact on deaths, however, was still reduced by shorter lockdowns and in scenarios where the release from isolation was immediate, rather than gradual.

The researchers then turned their attention to other countries. Indonesia was chosen because it doesn’t have pronounced seasons, while Argentina was picked because it is about to enter winter. Despite those differences, however, the model suggests a similar pattern of viral spread, with a second wave coming around January: sooner for shorter lockdowns, later for longer ones. For countries like Japan and New Zealand, however, the aggressive approach to handling the pandemic has left them in such good shape that there was no scenario in which a second wave occurred before 2021. If they did a longer lockdown and a more gradual reopening, the second wave might not arrive until nearly a year from now.

The big exception to all of this is the United States. In the case of shorter lockdowns—which is what we’ve essentially done in many states—the current rise grows to about 10 million infections before building to an enormous peak in late summer, with over 50 million infections. Longer lockdowns, at best, delay that to the winter and shave the peak by about 10 million. In short, even the best case of a hundred-day lockdown only stops the current peak and delays a resurgence so that it occurs around the same time as those in the worst cases for other countries.

Variations

López and Rodó also looked at some variations on the other interventions their model explored. They tried changing the number of people released from confinement during their gradual reopening. While they reasoned that they could put much of a country back to work by having two times the people outside confinement as there were inside, they found little difference between the results from that and the results when 10 times as many people were unconfined as remained isolated. So, as long as the release is gradual and the highest-risk individuals are kept confined, it’s possible to handle reopening safely.

This contrasts sharply with trying to alter the rate at which people are allowed out of the lockdown. Boosting the rate by a factor of 10 always produced a substantially higher second wave, regardless of how long the lockdown was for. The wave also arrived more quickly.

The researchers also modeled risk awareness by altering the rate at which the susceptible population took precautions that limited the spread of the virus, like maintaining social distancing and using face masks. They found that high levels of public awareness, when coupled with lockdowns and a gradual reopening process, was capable of blocking a second wave of pandemic entirely. The complete absence of these sorts of behaviors, in contrast, accelerated second waves so that they occurred earlier in 2020.

Next up, López and Rodó looked at the role immunity would play by allowing people from the recovered population to move back into the susceptible pool, testing rates that assumed everything from a short immune period of four months to one lasting a year. Not surprisingly, having longer periods of immunity could double the amount of time between subsequent waves of infection and reduce the size of the peaks in each subsequent wave.

In summary…

Most of the findings here are consistent with work from other researchers. We’re already fairly sure about issues like whether lockdowns are effective and how social distancing and face mask use limit the rate of the virus’ spread. But López and Rodó put some quantitative weight behind the idea of gradual reopenings, which are being tried in a number of US states. “Gradual deconfinement strategies always result in a lower number of infections and deaths,” they conclude, “when compared to the sudden release of moderate to large portions of the population.”

The other thing that is clear is that we’re going to be engaged in an extended struggle with our own indifference and frustrations. “The use of social distancing, face masks, gloves, and other individual protection measures has a massive impact in reducing the current peak of active cases,” the authors write, “but diminished awareness over time of the threats of the pandemic may result in a new larger second epidemic wave.”

The other thing that’s clear from these models is that ending lockdowns while case numbers are still high is dangerous and can extend the ongoing peak. In this case, the US seems determined to demonstrate that the predictions of the model are borne out by real-world data.

Nature Human Behavior, 2020. DOI: 10.1038/s41562-020-0908-8 (About DOIs).

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COVID was the leading cause of death in Americans aged 45-54 in 2021

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Enlarge / A woman watches white flags on the National Mall on September 18, 2021 in Washington, DC. Over 660,000 white flags were installed here to honor Americans who have lost their lives to COVID-19 epidemic.

COVID-19 was the third leading cause of death in Americans between March 2020 and October 2021, accounting for one in every eight deaths.

In that time frame, COVID-19 ranked in the top five causes of death for every age group of people older than 15 years. Between January and October 2021, the pandemic disease was the leading cause of death among people 45 to 54 years old.

That’s all according to a study of national death certificate data, published Tuesday in JAMA Internal Medicine by researchers at the National Institutes of Health.

The study found COVID-19 caused roughly 700,000 deaths between March 2020 and October 2021. The pandemic disease trailed only heart disease and cancer, which caused roughly 2.15 million collectively in that time frame. The fourth and fifth deadliest afflictions in the US were accidental deaths—including car crashes, overdoses, and alcohol-related deaths—and stroke, which collectively caused around 624,000 deaths during that period.

The authors, led by Meredith Shiels, an expert in cancer epidemiology and genetics at the National Cancer Institute, broke up the time frame into two sections: the start of the pandemic in March 2020 to December 2020, and January 2021 to October 2021, the last month for which there was complete data. This revealed age-specific trends, likely driven partly by uptake of vaccines and other mitigation efforts.

In the 2020 period, COVID-19 was the second leading cause of death in people aged 85 and over, but, amid high vaccine uptake in this age group, it fell to the third leading cause of death from January to October 2021.

Younger adults saw the opposite trend. For those aged 45 to 54, COVID-19 was the fourth leading cause of death in the 2020 period but jumped to the leading cause of death in 2021. Likewise, in those aged 35 to 44, COVID-19 jumped from the fifth leading cause of death in 2020 to the second leading cause in 2021. And for those aged 15 to 24 and 25 to 34, COVID-19 wasn’t in the top five in 2020, but ranked as the fourth leading cause of death in both age groups in 2021.

For those aged 55 to 84, COVID-19 was the third leading cause of death in both time periods.

The study is limited by the potential for misclassifying deaths on death certificates. But the authors were careful to select a time cutoff that would limit provisional or incomplete data from skewing the findings. That meant, however, that the study did not include deaths from part of the delta wave or the towering omicron wave in January 2022. Since October 2021, around 300,000 additional people in the US have died from COVID-19.

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Russian astronauts use space station to promote anti-Ukraine propaganda

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Enlarge / Cosmonauts Oleg Artemyev, Denis Matveyev, and Sergey Korsakov pose with a flag of the Luhansk People’s Republic on the International Space Station.

The Russian state space corporation responsible for spaceflight activities, Roscosmos, on Monday posted images to its official Telegram channel showing three cosmonauts with the tri-color flags of the Luhansk People’s Republic and the Donetsk People’s Republic.

The photos were taken recently on board the International Space Station and show smiling cosmonauts Oleg Artemyev, Denis Matveyev, and Sergey Korsakov posing with the flags.

“This is a long-awaited day that residents of the occupied areas of the Luhansk region have been waiting for eight years,” the Roscosmos message stated. “We are confident that July 3, 2022, will forever go down in the history of the republic.”

The images and social media posting represent the most blatant use of the International Space Station—which is operated by the United States, Russia, Japan, Canada, and the European Space Agency—for Russian propaganda purposes since the invasion of Ukraine.

Luhansk and Donetsk are two breakaway “quasi-states” in the eastern region of Ukraine known as the Donbas. Ukraine and Russia have battled over the two regions since 2014, as Russia has agitated separatists in the Ukrainian territory. The United Nations does not recognize the two “republics,” and Ukraine has designated them as “temporarily occupied territories.” Fighting has heated up since the Russian invasion of Ukraine in February 2022. This past weekend, Russian forces claimed to have established control over the entire Luhansk region.

A professional relationship

NASA and Roscosmos, as well as other space agencies, have continued cooperating on the International Space Station since the invasion began. Some US officials have suggested that NASA should consider breaking ties with Russia in space due to the atrocities in Ukraine. However, the space agency’s administrator has defended the partnership on the basis that the station flies above geopolitical tensions on Earth. NASA also wants to keep flying the station, as breaking the US segment from the Russian segment would be difficult and potentially fatal to the operation of the orbital facility.

In an interview published Monday in the German publication Der Spiegel, NASA Administrator Bill Nelson reiterated this stance.

“In the midst of the Cold War, when the Soviet Union and the United States were mortal enemies and their nuclear weapons could be used at any time, a US and a Soviet spacecraft met in space in 1975,” Nelson said. “Peaceful cooperation continued even after the collapse of the Soviet Union. Our space shuttle docked with the Russian space station Mir. And then we decided to build the International Space Station together. Both countries are needed for operations, the Russians for propulsion, the Americans for power. We will continue to have a very professional relationship between cosmonauts and astronauts to keep this station alive.”

Nevertheless the provocative actions this weekend by Roscosmos, with its cosmonauts celebrating the so-called liberation of Ukrainian territory, brings the bloody conflict on Earth into space. To some observers, such as former NASA astronaut Terry Virts, Russia’s use of the space station for propaganda purposes is unacceptable.

“I am incredibly disappointed to see cosmonauts and Roscosmos using the International Space Station as a platform to promote their illegal and immoral war, where civilians are being killed every day,” said Virts, who flew side by side with Russians and commanded the space station in 2015. “The space station is supposed to be a symbol of peace and cooperation.”

Virts said NASA has largely been trying to look the other way when it comes to Russian actions, most notably when it comes to Roscosmos chief Dmitry Rogozin, who has made numerous jingoistic statements about the war. But in this case, he said, the agency really cannot afford to.

Seat swap

NASA’s cooperation with Russia may come into greater public focus in a couple of months. At present, a NASA astronaut named Frank Rubio is scheduled to fly on a Russian Soyuz spacecraft to the station in September. Around the same time, a Russian cosmonaut named Anna Kikina is due to fly on a SpaceX Crew Dragon vehicle to the station as part of the seat swap. The arrangement has not been formally agreed to by the US and Russian government.

In his German interview, Nelson defended the swap, saying, “It makes a lot of sense for us. You need both Russians and Americans to operate the space station. What happens if something is wrong with one of our spacecraft? We need the other vehicle as a back-up. And that’s why we will continue to have crew exchanges.”

Such an argument may soon ring hollow, however. Boeing’s Starliner spacecraft may make its first crewed test flight before the end of this year, and if it is successful NASA will have two US spacecraft capable of reaching the station.

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How the Yurok Tribe is bringing back the California Condor

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Enlarge / The California condor is a New World vulture, the largest North American land bird. This condor became extinct in the wild in 1987, but the species has been reintroduced in California and Arizona.

The first California condor to reach Yurok ancestral land in over a century arrived by plane and car in late March of 2022. The small plane that carried Condor 746 had a rough landing, and the bird was irritable. He rattled around in a large dog crate during the three-hour drive to the tribe’s newly built condor facility, in a remote location in Redwood National Park.

Once there, he hopped into the flight pen, a tall enclosure of wire mesh, furnished with log perches and a drinking pool. At 8 years old, Condor 746 is an adult, his naked head bright pink instead of the black found in younger birds. He’s on loan from the captive breeding program at the Peregrine Fund’s World Center for Birds of Prey in Boise, Idaho. His job is to act as the mentor for four juvenile birds who will become the founders of a reborn condor society in Yurok country.

“We have mentors because condors are so social,” says Joe Burnett, California Condor Recovery Program Manager at the Ventana Wildlife Society. Young birds in a pen with no adult will become unruly. “You get the Lord of the Flies syndrome,” says Burnett. He and his colleagues quickly learned that release programs need an adult to serve as a role model and enforce the social hierarchy that is crucial to the flock’s survival.

A few days after 746 arrived, Condor A0, age 2, entered the flight pen. The first thing she focused on was 746, lounging on a perch. Understanding that she was in a safe place, A0 checked out the food—the carcass of a stillborn calf—then flapped onto a perch and fluffed up her feathers, a sign of avian contentment. Three young male condors, tagged A1, A2, and A3, followed. The youngsters had been living together for months at other condor facilities in Boise, Idaho, and San Simeon, California, and they already felt at home with each other.

Condor, known as prey-go-neesh in the native language, is sacred to the Yurok people. The Yurok reservation lies along the Klamath River in northwest California, but much of the tribe’s ancestral land is now in the hands of government agencies or private landowners. The tribe has been working to bring back the California condor since 2003, when a group of elders identified the bird as a keystone species for both culture and ecology, and therefore the most important land-based creature in need of restoration.

Nineteen years after the Yurok made that bold decision, the condors arrived. Elders who had worked toward that pivotal moment watched as Tiana Williams-Claussen, director of the Yurok Wildlife Department, and her colleagues released each newcomer into the pen.

Williams-Claussen’s job is to understand the details of condor biology and to interpret Yurok culture for the wider world. A tribal member, she grew up on the coast near the mouth of the Klamath, and went off to Harvard University. She didn’t set out to be a condor biologist, but when she returned in 2007 with a degree in biochemical sciences, condor restoration was the work her people needed her to do. Williams-Claussen has since spent 14 years living and breathing condors, learning how to handle them, building partnerships with government agencies, and listening to what Yurok elders have to say about the great bird.

The California condor is a critically endangered species: In the 1980s, the total population dwindled to fewer than 30 individuals. Biologists concluded the species’ only chance of survival lay in capturing every living condor in order to breed the birds in captivity, safe from poisons and power lines.

Reintroducing condors to the wild proved difficult, however, and the process became a dramatic lesson for biologists on the importance of parenting and the slow pace of growing up among these long-lived, highly social birds. Scientists learned that time spent with adults was critical to the behavioral development of young condors. They also found that in a species where adults follow and protect their offspring for a year or more after the birds fledge, youngsters pioneering landscapes empty of condors require lots of human babysitting.

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