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WASHINGTON — A one-time lockdown won't halt the novel coronavirus and repeated periods of social distancing may be required into 2022 to prevent hospitals from being overwhelmed, Harvard scientists who modelled the pandemic's trajectory said Tuesday.

Their study comes as the US enters the peak of its COVID-19 caseload and states eye an eventual easing of tough lockdown measures.

The Harvard team's computer simulation, which was published in a paper in the journal Science, assumed that COVID-19 will become seasonal, like closely related coronaviruses that cause the common cold, with higher transmission rates in colder months.

But much remains unknown, including the level of immunity acquired by previous infection and how long it lasts, the authors said.

"We found that one-time social distancing measures are likely to be insufficient to maintain the incidence of SARS-CoV-2 within the limits of critical care capacity in the United States," lead author Stephen Kissler said in a call with reporters.

"What seems to be necessary in the absence of other sorts of treatments are intermittent social distancing periods," he added.

Widespread viral testing would be required in order to determine when the thresholds to re-trigger distancing are crossed, said the authors.

The duration and intensity of lockdowns can be relaxed as treatments and vaccines become available. But in their absence, on and then off distancing would give hospitals time to increase critical care capacity to cater for the surge in cases that would occur when the measures are eased.

"By permitting periods of transmission that reach higher prevalence than otherwise would be possible, they allow an accelerated acquisition of herd immunity," said co-author Marc Lipsitch.

Conversely, too much social distancing without respite can be a bad thing. Under one modelled scenario "the social distancing was so effective that virtually no population immunity is built," the paper said, hence the need for an intermittent approach.

The authors acknowledged a major drawback in their model is how little we currently know about how strong a previously infected person's immunity is and how long it lasts.

Virus likely here to stay

At present the best guesses based on closely-related coronaviruses are that it will confer some immunity, for up to about a year. There might also be some cross-protective immunity against COVID-19 if a person is infected by a common cold-causing betacoronavirus.

One thing however is almost certain: the virus is here to stay. The team said it was highly unlikely that immunity will be strong enough and last long enough that COVID-19 will die out after an initial wave, as was the case with the SARS outbreak of 2002-2003.

Antibody tests that have just entered the market and look for whether a person has been previously infected will be crucial in answering these vital questions about immunity, they argued, and a vaccine remains the ultimate weapon.

Outside experts praised the paper even as they emphasised how much remained unknown.

"This is an excellent study that uses mathematical models to explore the dynamics of COVID-19 over a period of several years, in contrast to previously published studies that have focused on the coming weeks or months," Mark Woolhouse, an infectious disease epidemiologist at the University of Edinburgh said.

"It is important to recognise that it is a model; it is consistent with current data but is nonetheless based on a series of assumptions — for example about acquired immunity — that are yet to be confirmed." 

By Issam Ahmed

CHICAGO — To determine when Americans can safely venture out of their home bunkers, scientists must first understand who has already contracted the new coronavirus that causes COVID-19.

Nasal swab tests can detect the active virus, but the lack of widespread testing in the United States to date has left scientists with only a fraction of the information they need to understand the scope of the pandemic. Getting the full picture, they say, will require a reliable test that can detect antibodies to the virus in people’s blood.

The blood tests — which doctors call serology tests — may ultimately answer the questions needed to contain the pandemic and set the nation on a path toward normalcy: How many people have recovered from the disease without ever being tested? How common is it to have the disease without suffering symptoms? Can a person with antibodies safely return to work without fear of infecting others — or being reinfected?

With these urgent questions looming, the Food and Drug Administration has allowed scores of serology tests onto the market without the usual approval process, provided they met certain criteria. But doctors and public health officials say the result is a dizzying array of test options and uncertainty about their accuracy.

The FDA has given emergency approval to one company’s serology test, strictly for laboratory use in helping to diagnose COVID-19 cases. “The results obtained with this test should only be interpreted in conjunction with clinical findings, and the results from other laboratory tests and evaluations,” the FDA stated in its notice on the Cellex test.

Dr Stephen Hahn, commissioner of the FDA, spoke over the weekend about the importance of serology tests, which he called “one of the keys” to managing the pandemic, while also expressing concerns about the accuracy of tests not yet approved by his agency.

“I am concerned that some of the antibody tests that are in the market that haven’t gone through the FDA scientific review may not be as accurate as we’d like them to be,” Hahn said on ABC’s “This Week” news show. “No test is 100 per cent perfect. But what we don’t want are wildly inaccurate tests. Because, as I said before, that’s going to be much worse.”

In Chicago, Public Health Commissioner Allison Arwady said last weekend that a serology test her department was using had a higher rate of false negatives and positives than the nasal swab tests it also uses. The health department did not respond to questions about which blood test that was.

But, as she has before, Arwady stressed the essential nature of serology tests to taming the pandemic, saying they are “such an important thing.” She added that she was anxious to see which tests the FDA would eventually clear for use.

Dr Anthony Fauci, the federal government’s point person on the pandemic, told The Associated Press that most of the serology tests on the market have not been proved to work well. The infectious disease chief at the National Institutes of Health, Fauci said his staff is working with the FDA to validate the tests.

Some local institutions are already using the tests for diagnostic purposes. At a drive-up testing facility set up at Roseland Community Hospital on Chicago’s South Side, hundreds of people a day are getting the nasal swab, a blood test or both, said Dr Terrill Applewhite, chairman of the hospital’s COVID-19 task force.

Applewhite said he’s confident in the accuracy of the test the hospital is using.

With the goal of understanding the true scope of the pandemic, the National Institutes of Health has developed an in-house test that scientists plan to use as part of a new study announced last week. The study’s main objective is to determine how widespread the disease is and which communities have been hit hardest.

Part of the inquiry will involve trying to ascertain what percentage of the population that contracted the virus never got sick, a phenomenon that was discovered through previous testing.

People infected but free of symptoms were found on cruise ships, living in Italy and playing for the NBA. But just how many of those fortunate people exist is not known, and scientists are trying to pinpoint the real number. It’s a key question, given that asymptomatic patients may be silent spreaders of the virus.

The study involves collecting up to 10,000 blood samples from adult volunteers who don’t have COVID-19 symptoms and were not previously diagnosed with the disease. The blood will be collected either at designated labs or through mail-in kits.

Similar smaller studies exist but are not sufficient to give scientists a complete picture of the pandemic here in the United States, said Kaitlyn Sadtler, chief of immuno-engineering at NIH’s National Institute of Biomedical Imaging and Bioengineering.

The data from the NIH study will be combined over time with that from other research projects, Sadtler said. “This will be a giant team effort, with all scientists across the country,” she said.

Gigi Gronvall, a senior scholar at Johns Hopkins Centre for Health Security, said her institution is advocating for widespread use of antibody tests as part of a broader strategy to fully understand, manage and eventually end the pandemic.

“There’s a lot we need to know about this disease, so finding the prevalence in the population will be a big deal to [help people] know where you are more or less at risk, more or less likely to bump into someone who is infected,” she said. The testing, she added, also will be “part of a larger strategy for how people will go back to work and so forth.”

Gronvall said serology testing also could eventually answer trickier questions, such as what level of antibodies a person needs to be protected and how long those antibodies last.

“This is a new virus,” Gronvall noted. “We don’t know exactly what level of immunity you would need to protect against this infection. … Probably people who have had it are going to be immune for some time, but we don’t know what the expiration date is on immunity. And it’ll probably be different for different people, but we don’t know the range.”

In addition, Gronvall said, identifying antibodies that ably neutralise the virus could help lead to treatments or, ideally, a vaccine.

But, for now, the testing is being done mostly in an effort to understand the scope of the pandemic and help determine when it’s safe for people to venture out — at least until there’s a more sweeping solution.

 “The best solution here is going to be a vaccine… and so whatever we can do to test as many people until that time comes is a bridge,” Gronvall said.

Doctors on the ground say they are eager for the day when the FDA certifies the accuracy of tests that can be widely used. Part of the attraction is that serology tests are less expensive and simpler to process than the nasal swab tests.

“It’s a fairly cheap test, which is good, and it will tell you if you have you antibodies to the coronavirus, and that’s a very helpful piece of information,” said Dr Rahul Khare, founder and CEO of Innovative Express Care, an immediate care facility on the North Side. “I think there’s going to be, in late May or June, two types of people: those who have been exposed and are immune and those who have not who may get it.

“What we really want to know is of the people who have chronic conditions, who are elderly — have they gotten it and do they have to be extremely careful until there’s a way they can get antibodies to this somehow — be it by vaccine, be it by plasma transfusion — we don’t know yet,” he added. “But there will hopefully be a mechanism to develop those antibodies so the reaction of the body won’t be so great, causing all these illnesses that we’re seeing.”

By Hal Dardick

SAN FRANCISCO — Google and Apple unveiled a joint initiative Friday to develop a coronavirus smartphone "contact tracing" tool that could potentially alert people when they have crossed paths with an infected person.

The move brings together the largest mobile operating systems in an effort to use smartphone location technology to track and potentially contain the global COVID-19 outbreak.

The move would allow apps to be created enabling smartphones powered by Apple software and Google-backed Android operating system to exchange information with a joint "opt in system" using Bluetooth wireless technology.

The companies next month plan to release software interface technology to allow for interoperability — so that an alert would work regardless of the operating system.

"All of us at Apple and Google believe there has never been a more important moment to work together to solve one of the world's most pressing problems," the companies said in a joint statement.

The move comes with governments around the world studying or implementing measures to use smartphone location technology to identify people with the virus and keep them from infecting others, even as the efforts raise privacy and civil liberties concerns.

US President Donald Trump said during a briefing that the government would take "a very strong look" at the contact-tracing collaboration.

Privacy price?

Apple and Google contended that "privacy, transparency, and consent" were top priorities in the joint initiative, addressing concerns about systems which could disclose personal data on individuals.

"Contact tracing can help slow the spread of COVID-19 and can be done without compromising user privacy," Apple chief executive Tim Cook said in a tweet.

Tracking people's movements using their smartphones, while a temptingly powerful tool for containing the coronavirus comes with privacy concerns and fears regarding how the data might be misused.

"No contact tracing app can be fully effective until there is widespread, free, and quick testing and equitable access to healthcare. These systems also can't be effective if people don't trust them," said Jennifer Granick of the American Civil Liberties Union in a statement.

"People will only trust these systems if they protect privacy, remain voluntary, and store data on an individual's device, not a centralized repository,"

Apple and Android combined essentially power the world's smartphones, so working together would be required to effectively trace coronavirus contacts based on mobility data, according to analysts.

Apple has long made user privacy a selling point for iPhones, and is bringing those credentials to the coronavirus collaboration, noted Creative Strategies analyst Carolina Milanesi.

"Apple is providing their privacy seal, of sorts, to what is being done," Milanesi said. "That is good."

However, neither Apple nor Google can guarantee what ultimately becomes of mobility data gathered for the coronavirus fighting effort, warned analyst Patrick Moorhead of Moor Insights and Strategy.

"You put these two companies' ecosystems together and you have literally 100 per cent of mobile data," Moorhead said.

Technology-enabled or digital contact tracing has played a "conspicuously visible" part of the pandemic responses of South Korea, Singapore, Israel, and other nations, law professor and privacy researcher Ryan Calo said in Senate testimony this week.

"I understand the intuition behind digital contact tracing," Calo said in prepared remarks.

"But I see the gains in the fight against the virus as unproven and the potential for unintended consequences, misuse, and encroachment on privacy and civil liberties to be significant."

By Glenn Chapman

GENEVA — The novel coronavirus is 10 times more deadly than swine flu, which caused a global pandemic in 2009, the World Health Organisation said Monday, stressing a vaccine would be necessary to fully halt transmission.

WHO chief Tedros Adhanom Ghebreyesus told a virtual briefing from Geneva that the organisation was constantly learning about the new virus sweeping the globe, which has now killed nearly 115,000 people and infected over 1.8 million.

"We know that COVID-19 spreads fast, and we know that it is deadly, 10 times deadlier than the 2009 flu pandemic," he said.

WHO says 18,500 people died of "swine flu", or H1N1, which was first uncovered in Mexico and the United States in March 2009, but the Lancet medical estimated the toll to be between 151,700 and 575,400.

The Lancet review included estimated deaths in Africa and Southeast Asia that were not accounted for by the WHO.

The outbreak, which was declared a pandemic in June 2009 and considered over by August 2010, turned out to be not as deadly as first feared.

Vaccines were rushed out, but in hindsight, the West, particularly Europe, and the WHO were criticised for overreacting at a time when annual influenza epidemics every year killed between 250,000 and 500,000 people, according to WHO.

Tedros lamented Monday that some countries are seeing a doubling of cases every three to four days, but stressed that if countries were committed to "early case-finding, testing, isolating [and] caring for every case and tracing every contact" they could rein in the virus.

More than half of the planet's population is currently staying home as part of efforts to stem the spread of the virus, but Tedros warned that "our global connectedness means the risk of re-introduction and resurgence of the disease will continue".

He pointed out that while COVID-19 had accelerated quickly, "it decelerates much more slowly."

"In other words, the way down is much slower than the way up," he said, stressing that "control measures must be lifted slowly, and with control. It cannot happen all at once."

"Control measures can only be lifted if the right public health measures are in place, including significant capacity for contact tracing," he said.

Regardless of the efforts put in place, the WHO acknowledged that "ultimately, the development and delivery of a safe and effective vaccine will be needed to fully interrupt transmission".

A vaccine is thought to be at least 12 to 18 months away.

The flagship version of Audi’s flagship model, and available only as a special order – depending on market – the current Audi A8 L W12 is set to be the last application of the German manufacturer’s magnificent four-bank 12-cylinder engine, as it focuses on downsizing and efficiency. Ultra smooth and abundant is as indulgent in its delivery and ability, the A8 L W12 is similarly the lost luxurious version on offer, and – as driven – featured nearly the full gamut of Audi’s high tech systems developed for to outdo the competition in a technologically ever-escalating large luxury car segment.

Showcasing the future

Driven briefly during the A8’s initial launch and before this top-of-the-line model was even fully certified for production, the tested W12 represents the pinnacle of the A8’s sophistication, with many of the model line’s more advanced systems. The world’s first level three autonomous production car – on a scale of five – when its systems are fully unlocked depending on legislation in various markets, the A8’s innovative features centre around its Audi AI [artificial intelligence] processing system and standard 48-volt mild hybrid technology, the latter of which recovers power through regenerative braking and powers numerous electrical systems.

Almost exclusively powering electrical and more advanced assistance and safety systems without interfering with or corrupting the A8’s driveline operation, Audi’s 48v starter/generator system can, however, pitch in directly with a slight torque bump, depending on model and application. That said, the 48v system relieves the combustion engine of much ancillary system load and helps achieve a 0.7l/100km fuel consumption reduction. It also allows for brief coasting at speeds between 55-160km/h, and for stop/start system operation starting from 22km/h on deceleration, The 48v system also powers an optional fully independent active electromechanical suspension system.

Effortlessly effective

Effortlessly versatile and abundant, the flagship Audi’s magnificent twin-turbo 6-litre W12-cylinder engine is essentially a slightly de-tuned version of the same engine used by most range-topping Bentleys. Highly refined and progressive, the A8’s W12 produces a mighty 577BHP at around 6,000rpm and a massive 590lb/ft torque plateau throughout a broad and accessible 1,300-5,000rpm band. Responsive from standstill with its lightly boosted turbochargers and short gasflow paths, the A8 is expected to swiftly haul its estimated over 2.2-tonne mass through 0-100km/h in 4-seconds or little over, and onto an easily achievable electronically limited 250km/h top speed.

Moving swiftly and confidently with abundant mid-range flexibility and effortless across the board delivery, the W12 also benefits from a smooth and slick 8-speed automatic gearbox that optimises output for performance, efficiency and refinement. Putting power to tarmac through Audi’s Quattro four-wheel-drive system, the A8 develops high levels of road-holding and traction Driving with a 60 per cent rear bias for better agility, the A8 can apportion power back and forth for best grip in a prevailing situation, while optional four-wheel-steering makes it more agile despite its big heavy engine being positioned just ahead of the front axle.

Control and composure

Turning the rear wheels in the same direction as the front at higher speeds for better agility, road-holding and stability, and in the opposite direction for tighter cornering lines and manoeuvrability, four-wheel-steering effectively makes the long wheelbase A8 drive like a smaller car, and sublimely well manages the W12’s nose-heavy weighting, as demonstrated through a tight slaloms during test drive. Easy to manoeuvre and park with its 11.8-metre turning circle, cameras and vast array of driver-assistance and collision prevention sensors, warnings and semi-autonomous AI systems – where permitted – the A8 can also be fitted with optional remotely operated auto-parking.

Built using lightweight aluminium intensive construction and 24 per cent stiffer than its predecessor for improved handling, comfort and collision safety, the A8’s most impressive feature is, however, its active electromechanical suspension. Powered by its 48v system and controlled by its zFAS AI brain and high speed processing system, this leverages numerous sensors, radars and cameras to independently adjust each wheel’s vertical movement through individual electric motors. In concert with four-wheel-steering, active electromechanical suspension is a game-changer that makes the A8 handle with the agility of a smaller, lighter car, yet also improves ride comfort and stability.

Stately sophistication

Reading and responding to road texture, cornering forces and other parameters with intuitive fluency, the A8’s active electromechanical suspension delivers eagerly nimble, taut and sure-footed, cornering characteristics, and supple, forgiving ride composure. Hugely impressive, it also features predictive functions that further leverage the AI system, and allow the A8 to raise or lower individual wheels in time to keep the car level and smooth as it virtually glides over even significant bumps, cracks and imperfections. Fully active, the electromechanical suspension serves as a safety system that swiftly raises the A8’s body and point of impact when collision is anticipated.

A stately luxury car with sculpted surfacing, attention to detail and an elegantly assertive demeanour, the A8’s design centres around its huge hexagonal grille. Luxurious, spacious and comfortable inside, the A8’s cabin is refined, quiet and brimming with high quality leathers, suede, metals and woods. Extensively equipped with comfort, convenience and safety systems too long to list, the A8 notably features a haptic button, advanced voice recognition dual screen infotainment system. Meanwhile, Audi AI’s self-driving features, when enabled depending on legislation, would be able to stop, start, steer and brake up to 60km/h in the right circumstances.

SPECIFICATIONS

• Engine: 6-litre, twin-turbo, in-line W12-cylinders
• Bore x stroke: 84 x 89.5mm
• Valve-train: 48-valve, DOHC, direct injection
• Gearbox: 8-speed automatic, four-wheel-drive
• Drive-line: self-locking centre differential, optional limited-slip rear-differential
• Power distribution, F/R: 40 per cent / 60 per cent
• Power, BHP (PS) [kW]: 577 (585) [430]
• Specific power: 97BHP/litre
• Torque, lb/ft (Nm): 590 (800) @1,300-5,000rpm
• Specific torque: 134.5Nm/litre
• 0-100km/h: approximately 4-seconds (estimate)
• Top speed: 250km/h (electronically governed)
• Length: 5,302mm
• Width: 1,945mm
• Height: 1,488mm
• Wheelbase: 3,128mm
• Track, F/R: 1,644 / 1,633mm
• Approach / departure angles: 14° / 13.7°
• Aerodynamic drag co-efficient: 0.27
• Luggage volume: 505-litres
• Unladen weight: approximately 2,200kg (estimate)
• Steering: Electric-assisted rack & pinion, all-wheel steering
• Turning Circle: 11.8-metres
• Suspension: Five-link, active electro-mechanical suspension
• Brakes: Ventilated & perforated discs
• Tyres: 265/40R20

LOS ANGELES — A sheet of paper bearing Paul McCartney's handwritten lyrics to "Hey Jude" sold for $910,000 in an online auction held Friday to mark the 50th anniversary of the Beatles' historic split.

The document penned by McCartney and used during the 1968 London recording of the classic song at Trident Studios was sold for more than five times its pre-sale estimate.

California-based Julien's Auctions shifted its sale of some 250 Beatles memorabilia online due to the coronavirus pandemic, with fans around the world bidding for guitars, rare vinyl and autographed items.

Friday marks exactly half a century since an interview given by McCartney sealed the acrimonious end of the "Fab Four," widely considered one of the most influential bands in history.

Asked if he foresaw a time when his prolific songwriting partnership with fellow Beatle John Lennon would restart, his blunt reply — "no" — spoke for itself.

McCartney wrote "Hey Jude" after an earlier split — Lennon's divorce from first wife Cynthia following his affair with Japanese artist Yoko Ono.

The song was composed to comfort Lennon's son Julian during his parents' break-up, and was initially titled "Hey Jules."

The handwritten document sold Friday contains partial lyrics along with annotations including the word "break" used to aid the song's recording.

Other items included a drumhead with the Beatles' logo used during their first US tour gig in 1964, sold for $200,000, and a handwritten shooting script page for the "Hello, Goodbye" music video in 1967, fetching $83,200.

A brass ashtray used by Ringo Starr at the Abbey Road recordings in the 1960s earned $32,500.

The Circle

Dave Eggers

New York: Vintage Books, 2014

Pp. 497

“The Circle” is a novel bordering on science fiction of the type that could conceivably become true.

Mae is a very bright young woman from a small nondescript California town. After graduating from college, she had worked at the local utilities company for over a year, enduring boredom and non-recognition of her considerable computer skills but stayed on because she needed to pay off her student loans. “All of it felt like something from another time, a rightfully forgotten time, and made Mae feel that she was not only wasting her life but that this entire company was wasting life, wasting human potential and holding back the turning of the globe”. (p. 11)

Everything changes when Annie, Mae’s former college roommate, helps her land a job at the Circle, the world’s leading tech company that has subsumed most of the others. Annie is part of the Gang of 40, the leading innovators and thinkers at the company, headed by three executives referred to as the Three Wise Men. The Circle seems modelled on the actual Google campus in Mountain View, California, but exponentially magnified. It’s a total environment with extensive eating, cultural, sports, fitness, social and medical facilities, in addition to offices, laboratories, exhibition halls and dormitories. The company takes good care of its employees; Mae is even able to get comprehensive health insurance for her parents, especially meaningful as her father suffers from a debilitating degenerative disease and is struggling with poor insurance coverage. A thousand threads link the employees to the company.

Mae begins in Customer Experience (once called customer service) and excels in her work, but she finds out that this is not enough. Employees are expected to attend the many events on campus and to keep in constant touch with their colleagues, friends and customers via social messaging. Soon she has multiple screens on her desk, each devoted to a particular type of communication. Going off on one’s own or doing something spontaneously off campus without communicating are viewed with suspicion; everyone should document, share and benefit from everything.

Oddly, one of the Wise Men, the boy genius who envisioned the idea of the Circle and devised the technology that made it possible, is seldom seen around the campus anymore. But his invention is pervasive: The Unifying Operating System combines users’ social media profiles, payment systems, passwords, email accounts, preferences, tools, etc. “You had to use your real name, and this was tied to your credit cards, your bank… One button for the rest of your life online… Though some sites were resistant at first, and free-internet advocates shouted about the right to be anonymous online, the TruYou wave was tidal and crushed all meaningful opposition… the actual buying habits of actual people were now eminently mappable and measurable, and the marketing to those actual people could be done with surgical precision”. (pp. 21-22)

Most users are delighted as it simplifies their lives, but there are a few detractors. According to Mae’s ex-boyfriend, who wants to live a different kind of life, “the tools you guys create actually manufacture unnaturally extreme social needs”. (p. 134)

Having created a strong commercial base, the Circle expands into other fields with multiple projects aimed at eliminating all society’s ills and documenting everything, such as how many trees in the Amazon rainforest, to arrive at total knowledge. All this data is stored on the cloud and non-deletable. With the aim of ending child abductions, chips can be implanted in all children to track their location. With the aim of ending corruption and deepening democracy, politicians are encouraged to wear a device to make all their actions transparent. Those who don’t wear the device are assumed to be doing something wrong. Soon everyone could wear it, their every action being broadcast on public screens. The Circle is closing: Everyone is transparent, and everything can be known. The Circle is poised to take over governmental functions. Mind-reading and mind-control are only a click away.

Eggers’s implicit subtext is that the Circle is a very “white”, elite enterprise where social mobility depends on unquestioningly adopting certain values and practices. Under a veneer of choice, there is subtle, but effective coercion. Employees can vote on many things, such as if they want more vegetarian options at lunch, but larger priorities are already set in stone. What will happen to the outliers, the poor and the socially disadvantaged who have no access to this system? In effect, two parallel worlds are emerging: Mae “found it difficult to be off-campus… There were homeless people, and there were the attendant and assaulting smells, and there were machines that didn’t work, and floors and seats that had not been cleaned, and there was, everywhere, the chaos of an orderless world”. (p. 373)

With the fast-paced, riveting story of Mae’s induction into the Circle, Eggers shows the dangers of runaway technology even if guided by geniuses with utopian ideas. There is also an implicit critique of neoliberalism which eats away at government responsibility for its citizens. The story poses urgent questions: Should being “connected” be mandatory all the time? Are thousands of virtual friends better than solid, face-to-face friendships? Does society need to know everything? Should privacy be obliterated? Can the world be perfect?

WASHINGTON — A new study examining air samples from hospital wards with COVID-19 patients has found the virus can travel up to four metres — twice the distance current guidelines say people should leave between themselves in public.

The preliminary results of the investigation by Chinese researchers were published Friday in Emerging Infectious Diseases, a journal of the US Centres for Disease Control and Prevention (CDC).

They add to a growing debate on how the disease is transmitted, with the scientists themselves cautioning that the small quantities of virus they found at this distance are not necessarily infectious.

The researchers, led by a team at the Academy of Military Medical Sciences in Beijing, tested surface and air samples from an intensive care unit and a general COVID-19 ward at Huoshenshan Hospital in Wuhan. They housed a total of 24 patients between February 19 and March 2.

They found that the virus was most heavily concentrated on the floors of the wards, "perhaps because of gravity and air flow causing most virus droplets to float to the ground."

High levels were also found on frequently touched surfaces like computer mice, trashcans, bed rails and door knobs.

"Furthermore, half of the samples from the soles of the ICU medical staff shoes tested positive," the team wrote. "Therefore, the soles of medical staff shoes might function as carriers."

Airborne threat?

The team also looked at so-called aerosol transmission — when the droplets of the virus are so fine they become suspended and remain airborne for several hours, unlike cough or sneeze droplets that fall to the ground within seconds.

They found that virus-laden aerosols were mainly concentrated near and downstream from patients at up to 4 metres — though smaller quantities were found upstream, up to 2.4 metres away.

Encouragingly, no members of the hospital staff were infected, "indicating that appropriate precautions could effectively prevent infection," the authors wrote.

They also offered advice that bucks orthodox guidelines: "Our findings suggest that home isolation of persons with suspected COVID-19 might not be a good control strategy" given the levels of environmental contamination.

Aerosolisation of the coronavirus is a contentious area for scientists who study it, because it is not clear how infectious the disease is in the tiny quantities found in ultrafine mist.

The World Health Organisation has so far downplayed the risk.

US health authorities have adopted a more cautious line and urged people to cover their faces when out in public in case the virus can be transmitted through normal breathing and speaking.

LOS ANGELES — The much-anticipated "Friends" reunion has been delayed and will not be available at the launch of HBO Max, the new streaming platform said Friday, as the global coronavirus pandemic shuts down productions across Hollywood.

News of the unscripted special had delighted fans of the beloved US sitcom, which remains wildly popular even among viewers too young to remember its original run, which ended in 2004.

Stars Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matt LeBlanc, Matthew Perry and David Schwimmer have signed up to return to the comedy's original soundstage on the Warner Bros. Studio lot outside Los Angeles.

But a spokesman told AFP Friday the special will not be available for HBO Max's May launch as planned, adding that it will be coming to the streaming platform "soon." 

Production has not yet taken place due to the coronavirus lockdown, part of measures put in place for billions around the globe to break transmission of the virus which has killed more than 100,000 people worldwide.

A remote or virtual reunion was not considered due to the significance of the original soundstage, according to Variety.

Each actor is expected to receive $2.5 million for taking part in the special, it reported.

WarnerMedia's Sean Kisker this week confirmed the May launch of HBO Max itself, which will cost $14.99 a month, remains "still very much on" schedule.

The "Friends" back catalogue is a key selling point for the new streaming platform as it enters a fiercely competitive marketplace alongside Netflix, Disney+, Amazon Prime and Apple TV+.

Unveiling the special in February, Kevin Reilly, chief content officer at HBO Max, said the show about a close-knit group of friends living in New York City had captivated "viewers generation after generation." 

"It taps into an era when friends — and audiences — gathered together in real time and we think this reunion special will capture that spirit, uniting original and new fans," he said.

Aniston's Instagram post in February teasing the special drew nearly 4.8 million likes in three hours.

"Friends" was among the most-watched shows on Netflix until all 10 seasons of the show were reclaimed last year by WarnerMedia, which owns HBO Max.

Seen on US television from 1994 to 2004, it won dozens of awards and garnered global celebrity for Aniston and her co-stars.

PARIS — Before the emergence late last year of the novel coronavirus, which has now killed more than 100,000 people, the 21st century's epidemics had been far less deadly than the pandemics of the previous century.

Here are the major epidemics of the last two centuries, starting with the most recent:

Ebola: 2013-2016 and 2018-to date

The deadliest epidemic of the haemorrhagic fever Ebola broke out in West Africa in December 2013 and lasted more than two years, killing more than 11,300 people, mainly in Guinea, Liberia and Sierra Leone.

First identified in 1976, Ebola is less contagious than other viral diseases, but is particularly lethal, killing around 50 per cent of cases.

The virus re-emerged in August 2018 in the eastern Democratic Republic of Congo where it has so far killed more than 2,200. On April 10, 2020 a new case was reported, just three days before a deadline that would have marked the official end to the epidemic.

Swine flu: 2009-2010

The World Health Organisation (WHO) says 18,500 people died of "Swine flu", or H1N1, which was first uncovered in Mexico and the United States in March 2009.

The Lancet medical review, however, puts the toll at between 151,700 and 575,400.

The pandemic alert was launched on June 11, 2009 and lifted on August 10, 2010 but the virus turned out to be not as deadly as first feared.

Vaccines were rushed out, but in hindsight, the West, particularly Europe, and the WHO were criticised for overreacting at a time when annual influenza epidemics every year kill between 250,000 and 500,000 people, according to the Geneva-based UN health agency.

Bird flu: 2003-2004

The deadly H5N1 strain of bird flu killed more than 400 people, mainly in Southeast Asia, after appearing in 2003. It first ravaged poultry farms in Hong Kong, before being transmitted to humans. The WHO declared a global health emergency, but the toll remained limited.

SARS: 2002-2003

Severe Acute Respiratory Syndrome first emerged in southern China in November 2002 before sparking a health crisis in mid-2003, in particular traumatising Asia.

It killed 774 people, four fifths of whom were in China and Hong Kong. It was transmitted to humans from horseshoe bats, eventually spreading to around 30 countries. It had a mortality rate of 9.5 per cent.

AIDS: 1981-to date

AIDS is by far the most deadly epidemic of modern times: according to UNAIDS some 32 million people around the world have died of the disease which affects the immune system and leaves people vulnerable to opportunistic infections.

Today around 24.5 million people have access to retroviral drugs which, when taken regularly, efficiently stop the illness in its tracks and heavily reduce the risk of contamination.

Hong Kong flu: 1968-1970

Around one million people died of the Hong Kong flu, according to the US Centers for Disease Control and Prevention (CDC).

Transmitted around the world between mid-1968 and early 1970, it in particular killed many children. It first started in Hong Kong, spread through Asia and reached the United States in late 1968. After lying low for several months it then hit Europe in late 1969.

Asian flu: 1957-1958

Around 1.1 million people died of Asian flu, according to the CDC.

The pandemic hit in two aggressive waves. The virus first appeared in southern China in February 1957. Several months went by before it reached America and Europe.

The disease, which results in serious lung complications, in particular affected the elderly.

1918-1919: Spanish flu

Spanish flu hit a large part of the world's population in the wake of World War I, killing up to 50 million people, according to the CDC.

Striking between September 1918 and April 1919, it is considered the most deadly in history over such a short period.

Five times more people died of it than did in World War I. The first victims were recorded in the United States, before it spread to Europe and then around the world.

Its mortality rate was estimated at more than 2.5 per cent, according to the CDC.

By Olivier Thibault  and Jean-Philippe Chognot