The Washington Post this week analyzed data from the European Space Agency’s Sentinel-5P satellite, which can measure concentrations of greenhouse gases and other pollutants in the lower atmosphere. It shows that between Jan. 1 and March 12, concentrations of nitrogen dioxide, or NO2, fell drastically, especially over hard-hit northern Italy.

Nitrogen dioxide is not one of the major greenhouse gases linked to climate change. But it is produced from combustion – by cars, power plants, and other industrial sources. So it serves as a proxy for other emissions that warm the atmosphere. It also is a pollutant that can increase the risk of asthma, inflammation of the lungs and other harmful health conditions. Several experts told The Washington Post that the changing concentrations probably reflect the decline of driving in particular, in a country in which more than half of cars burn diesel.

“I guess this is mostly diesel cars out of the road,” Emanuele Massetti, an expert on the economics of climate change at Georgia Tech University who has studied Italy’s climate policies, said in an email.

“I expect pollution to drop even further as the particles in the atmosphere (concentration) get either dispersed or absorbed,” he continued. “In a few days, they will enjoy the cleanest air ever in northern Italy.”

That shift is little comfort, of course, to a region in the grips of a deadly outbreak, wrestling with an overwhelmed health system and understandably focused on the crisis at hand rather than the long-term effects of climate change. At the same time, the stark changes offer yet another example of the impact humans have on the environment – and how swiftly emissions can vanish when humans drastically reduce the burning of fossil fuels.

Despite the wide use of diesel engines, Italy’s electricity sector doesn’t burn a massive amount of coal, Massetti said – rather, it is driven largely by natural gas and renewable energy.

Greenhouse gas emissions in the country also have plummeted in recent years. That’s one reason Massetti said he thinks the emissions decline mainly represents a steep decrease in the driving of diesel vehicles. The transportation sector produces more than 70 percent of all nitrogen dioxide emissions in Milan, according to a recent analysis by the European Commission’s Joint Research Center.

“This makes a lot of sense especially since it shows that the highest decrease in concentration has happened in Lombardy, where the most stringent choices were taken first,” Edoardo Marcucci, who directs the Transport Research Lab at Roma Tre University in Rome, said in an email. “I would expect that to become true for the whole country in the next few days.”

Riccardo Valentini, a professor at Italy’s University of Tuscia and director of the impacts division of the Euro-Mediterranean Center on Climate Change, said in an email that the country’s aggressive measures to contain the virus have had a profound effect on everyday life – and by extension, on emissions.

“Nobody can go out from homes unless for precise working duties and/or food purchase or health emergency,” he said. “For sure, there has been a decline of car traffic everywhere. This explains the NOx emission decline.”

He added that Italy’s troubles could potentially soon extend throughout the region and to other parts of the globe. “We are the first E.U. country to get the epidemic outbreak, but numbers are increasing in Spain, France and Germany, plus the others,” Valentini wrote, adding, “The real impact on climate policies could vary country by country depending on the size of the containment measures.”

In the United States, for example, school closures, event cancellations and work-from-home policies will mean millions of people are no longer commuting by car during rush hour, resulting in pollution declines here, too. Beyond the public health and economic crises, he said, the pandemic ultimately could trigger the most significant reduction of greenhouse gas emissions of the past century.

While the ongoing crisis has drastically slowed emissions in China, Italy and potentially elsewhere, that has offered little cause for celebration.

“It is, of course, not a good thing,” Valentini wrote. “This is not the way to reduce emissions!”

Climate advocates agree, saying the current catastrophe is not the way any reasonable person would envision the world lowering its carbon footprint. In addition, the outbreak has halted meetings to plan for public protests for climate action in the coming months, as well as the global push to get nations to commit to more ambitious emission reduction plans at a key U.N. summit scheduled for this fall.

Moreover, the drop in emissions is expected to be temporary. “This will have just a minor effect of global concentrations of CO2, unless it leads to a really long depression of the world economy,” Massetti said.

Italy has been a world leader in its reductions of greenhouse gases in recent years. Carbon dioxide emissions in the country declined by over 30 percent between 2004 and 2018. Last year, Italy announced that it planned to become the first country to make it mandatory for schoolchildren to learn about climate change and sustainable development.

Italian education minister Lorenzo Fioramonti said at the time that beginning this September, teachers in all state schools and all grades would dedicate 33 hours per year – nearly an hour per week of instruction – to issues related to climate change and environmental sustainability.

For now, however, all schools in Italy remain closed.

Mathematical models developed by epidemiologists to track the virus show a sharp trajectory of infections in Spain, Germany, France and Britain. Spain, which declared a state of emergency Friday, showed particularly concerning exponential growth, experts said.

The modelers in Europe say a similar arc is likely in the United States, but anticipating the spread is made more difficult by the lack of widespread testing. U.S. officials are working with 50 academic modeling groups, but no forecasts have been released by the Centers for Disease Control and Prevention or the White House coronavirus task force. One model, for the American Hospital Association, projects a worst-case scenario of hundreds of thousands of deaths.

“Italy is about two weeks ahead of Britain and the rest of Europe,” said Francois Balloux, director of the Genetics Institute at University College London.

Observations by epidemiologists show that if unchecked, the number of infections double approximately every five days, with infected individuals, on average, capable of passing the virus on to an average of about 2.5 people.

“What we are seeing is not rocket science,” Balloux said. “You have two cases, then four, then eight, then 16.”

Epidemiologists say that decisive action is required to change the rate of infection and “flatten the curve.” That reality appeared to sink in for some political leaders in the United States and Europe this week, as countries closed schools, encouraged working from home, banned large gatherings and imposed new travel restrictions. French Health Ministry Director General Jérôme Salomon said France must prepare itself for “the Italian scenario.”

Still, some experts worry that governments aren’t doing enough to reduce rates of transmission so cases don’t soar exponentially and overwhelm health systems. A lack of urgency in previous weeks may have wasted valuable time, they say.

On Friday, the director-general of the World Health Organization, Tedros Adhanom Ghebreyesus, said, “Europe has now become the epicenter of the pandemic, with more reported cases and deaths than the rest of the world combined, apart from China.”

Irish doctors on Friday warned in a letter to the British Medical Journal that the country is “exactly 14 days behind Italy.” They said only stringent measures could head off a medical crisis like Italy’s and produce a more manageable outbreak like South Korea’s.

At the beginning of an outbreak, experts say viral spread can be contained by isolating individuals and tracing those in contact. But when cases begin to emerge where the infection source is unknown, as they have in parts of Europe and the United States, mass behavioral changes and social distancing appear to be the better strategy.

Italy is one country that has had to accept quickly the need for drastic action. Just three weeks ago, it did not have much of a coronavirus problem. Now it has had more than 15,000 confirmed cases. Prime Minister Giuseppe Conte extended a lockdown on a handful of small villages to wide swaths across northern Italy on Sunday morning and then to the entire country Monday night. On Wednesday, he went even further, with the announcement of a shutdown of most commercial activity.

Italy may have been particularly hard hit in part because the virus spread in the community for several weeks unchecked, and the government has had to play catch-up.

Dirk Brockmann, a professor at the Humboldt University in Berlin who does infectious-disease modeling for Germany’s Robert Koch Institute, the federal agency tasked with disease control, said looking at the number of confirmed cases at a particular moment can be misleading – if people think it is just a few thousand cases here and there.

“It’s almost like taking a still picture of cars on a highway, it doesn’t tell you anything,” he said. “It’s about how the numbers change.”

The current snapshot may be as much as two weeks old, given the time it may take for the virus to cause symptoms and for patients to be tested and diagnosed.

Britain’s chief science adviser, Patrick Vallance, said Thursday that the United Kingdom had 600 confirmed cases, which he said means that 5,000 to 10,000 people there probably are infected.

If the virus continues to infect people at its current rate, which is not a certainty, a European country such as Spain, with 3,000 cases, could see 250,000 infected individuals in about a month, based on doubling times of five days.

“Those are the numbers that epidemiologists are expecting,” said Roy Anderson, professor of infectious disease at Imperial College London.

“I think it’s highly likely we all go the way of Italy” in the coming weeks, he said.

Whether the caseloads explode will depend in part on public health controls, decisions by governments and businesses, and individual actions, the disease modelers say.

Many people were taken aback when Chancellor Angela Merkel on Wednesday warned that 60 to 70 percent of Germany’s population of 83 million could contract the disease.

But infectious-disease specialists say that’s quite possible.

“If governments do nothing, or do things that are not effective, and the population does nothing, then you certainly could see 60 percent of a population infected,” Anderson said.

Some European countries appear to be “renouncing efforts to contain the epidemic,” said Giovanni Rezza, director of the Infectious Disease Department at the Italian National Institutes of Health.

“We are applying very tough measures” in Italy, he said. “But in other countries where the incidents of the disease are increasing, it’s like they are not looking at Lombardy,” he added, referring to the Italy’s worst-hit region.

“For the other countries around us, we should be a lesson. They know the virus is there, so they should act more promptly,” Rezza said.

For the United States, Rezza said, there was still a “window of opportunity” to try to contain the virus, given the large geographical area and isolated outbreaks.

Infectious-disease specialists say it is possible the case numbers in the Northern Hemisphere will soar in March, and then begin to go down if the coronavirus proves to be seasonal, like common flu, which produces less infection in the warmer summer months.

The British government, especially, appears to be hoping the infection rate drops in April and May, but so far there is no evidence to support the optimism.

In northern Italy, where the wards are running out of beds for all the coronavirus patients, doctors report they are battling out-of-control transmission.

Earlier, a group of Italian doctors sent out an appeal to their colleagues working in intensive care units in Europe.

“Get ready,” they wrote.

Angelo Pan, head of infectious diseases at a hard-hit hospital in Corona, Italy, warned that without effective containment measures, a similar scenario could be ahead for France, Germany and possibly the United States.

“It’s just a matter of time,” he said. “I think we are just maybe 10 days ahead.”

Benjamin Maier, who is Brockmann’s research partner at Robert Koch Institute, has plotted the infection curves of countries in Europe and Asia that have seen outbreaks.

Spain is showing galloping exponential growth, he said, while Britain, Germany and France are still on a steep trajectory.

“You can see that many countries will follow Italy’s example if they don’t follow strict and stricter measures,” Maier said.

Those measures can have a significant impact on how many cases develop. Brockmann and Maier examined the epidemiological curves of the outbreak in China. Although Hubei province initially had an exponential growth rate, the government’s massive containment effort, involving mandatory behavior changes, managed to slow the rate of infection.

South Korea, which has carried out widespread testing, has identified nearly 8,000 cases, but the numbers of new infections are tapering off. Singapore, Malaysia and Japan also have seen flatter growth.

For those countries facing steep increases in coming weeks, all is not lost, said Alexander Kekulé, a German virologist who heads the institute of medical microbiology at the University of Halle.

Acting in advance, rather than in reaction to numbers that lag behind the picture on the ground by weeks, he said, can make a huge difference.

“This really decides if you win the battle, or you lose it,” he added. For weeks, Kekulé has publicly urged Germany to act more swiftly with measures to ban mass events, close schools and test everyone who has flu-like symptoms.

But China’s swift and drastic action is more of a challenge in Western democracies.

Politicians in Europe have been slow to make proactive decisions that could be lifesaving until the danger has sunk in for the public, said Kekulé, meaning they are reacting, rather than getting ahead of the curve.

The fact that German Health Minister Jens Spahn recommended events with more than 1,000 people be stopped on the same day that the first German national died was no coincidence, he said.

“It’s always the problem of a Democratic system; you have to explain yourself to your voters on why this measure has to be taken,” he said. “You have to wait until it’s hurting.”

Fabio Wajngarten, communications secretary for Brazilian President Jair Bolsonaro, posed for a photograph with Trump and Pence at a dinner for Bolsonaro at Mar-a-Lago, the president’s private club in Palm Beach, on Saturday.

Prominent members of the Trump administration and Trump family members also attended either the dinner or a party the same night in honor of former Fox News host Kimberly Guilfoyle, who is dating Donald Trump Jr.

Trump’s contact with Wajngarten is the latest example of a potential coronavirus close call for the president, who says he is following at least some of his administration’s advice about preventing the spread of the disease but also continues to play down the threat of a potentially deadly illness.

“Let’s put it this way: I’m not concerned,” Trump said Thursday as news broke that Wajngarten had fallen ill and tested positive for the virus after returning to Brazil.

Bolsonaro underwent testing and is awaiting results. Trump is not being tested and brushed off the risk Thursday.

“Yeah, I did hear something about that. We had dinner together in Florida in – at Mar-a-Lago, with the entire delegation,” Trump said. “I don’t know if the press aide was there. If he was there, he was there.”

“But we did nothing very unusual. We sat next to each other for a period of time, had a great conversation. He’s doing a terrific job in Brazil,” Trump said, referring to Bolsonaro. “And we’ll find out what happens. I guess they’re being tested right now, right?”

Trump did not seem to remember Wajngarten well, but a photo the aide posted on social media shows him standing shoulder to shoulder with Trump, with Pence on the president’s other side.

The interaction follows several instances in which Trump has spent time with members of Congress and others who had been in contact with an attendee at the Conservative Political Action Conference in late February who tested positive for the coronavirus after the conference ended. But word of the infection did not come until after Reps. Douglas Collins, R-Ga., and Matt Gaetz, R-Fla., had spent time with Trump.

Both congressmen opted to self-quarantine until it was clear they were not infected. Sen. Lindsey Graham, R-S.C., announced Thursday that he is doing the same “as a precautionary measure” after attending the Mar-a-Lago dinner. Like many Americans, Graham will be working from home.

Sen. Rick Scott, R-Fla., another dinner guest, announced a self-quarantine Thursday because of attendance at Mar-a-Lago, as did the mayors of Miami and Miami-Dade County.

No such announcements of quarantines or testing came on behalf of anyone at the White House – though Trump advisers Jared Kushner and Ivanka Trump, acting director of national intelligence Richard Grenell, national security adviser Robert O’Brien and others close to the president attended the dinner.

Donors who saw Trump in small settings this past weekend in Florida were asked when they last left the country and whether they’d had any flu-like symptoms but were not asked to undergo any additional screening, said people familiar with the arrangements who spoke on the condition of anonymity to discuss the sensitive issue. Trump attended at least four fundraisers over the weekend, some with dozens of attendees.

On Saturday, Trump interacted with a much larger group of people, including many who had not been asked screening questions. After dinner with the visiting Brazilian delegation, Trump went into the ballroom at Mar-a-Lago and stood amid the crowd and gave a toast to Guilfoyle.

He was seen shaking dozens of hands throughout the packed club, attendees said.

One person who was present said there is no way to know whether fellow guests were sick.

“You don’t get a health screening at Mar-a-Lago obviously,” this person said, speaking on the condition of anonymity to discuss private events at the club.

White House officials have sought to limit foreign leader contact at the White House going forward, according to a senior administration official.

Sitting alongside visiting Irish prime minister Leo Varadkar at the White House on Thursday, Trump acknowledged that he has adjusted his routine a bit.

“Well, we didn’t shake hands today. And we looked at each other. We said, ‘What are we going to do?’ You know, it’s sort of a weird feeling,” Trump said to laughter.

Varadkar said that the two leaders had opted for clasping their own hands together in front of their chests. He demonstrated, with a small tilt of the head.

Trump noted that in other cultures, in places such as India and Japan, people do not routinely shake hands, virus or no virus, and he seemed to approve.

“They were ahead of the curve, OK?” Trump said.

“It’s a very strange feeling,” he said. “You know, I was never a big hand-shaker, as you probably heard. But once you become a politician, shaking hands is very normal.”

Trump has described himself as a germaphobe, but since entering politics he has made peace with the rope line and the rally. Trump’s rallies often place thousands of people in close quarters for hours, something the president acknowledged Thursday he is reconsidering because of the virus risk.

But his motivation to continue with public events and to resist getting tested may be rooted in his aversion to any sign of weakness. People close to Trump described him as uninterested in being tested. He has told at least two advisers that if he gets sick, he will get tested.

A former aide said Trump never wanted to be viewed as sick, because he saw it as being weak. So even when Trump would come down with a cough or lose his voice, he would try to keep a strong public face – or staffers would come up with other reasons to move events. The former aide spoke on the condition of anonymity to describe Trump’s behavior.

Sounding somewhat dejected Thursday, Trump said he is unlikely to hold big rallies for a while. He has canceled events this weekend in Nevada and Colorado and said a previously unannounced event in Tampa is unlikely to go forward.

The Secret Service has not advised Trump to stay close to home, he said.

“They have not, but it’s common sense,” Trump said. “You know, a lot of it is – and what I say is: Use common sense, like washing your hands and, you know, certain things. Keep a little bit of distance away.”

But still, no test, according to White House press secretary Stephanie Grisham.

“Exposures from the case are being assessed, which will dictate next steps,” she said in a statement Thursday. “Both the President and Vice President had almost no interactions with the individual who tested positive and do not require being tested at this time.”

She added that under guidelines from the Centers for Disease Control and Prevention, “there is currently no indication to test patients without symptoms, and only people with prolonged close exposure to confirmed positive cases should self-quarantine.”

Meanwhile, test results for Bolsonaro, who sat next to Trump at dinner, were expected Friday.

“The medical service of the presidency of the Republic has adopted and is adopting all of the necessary preventive measures to preserve the health of the President of the Republic and the entire presidential committee that accompanied him in the recent official trip to the United States,” the presidential press office said in a statement.

In yet another sign of how difficult the pandemic may be to contain, doctors in China detected the virus’ RNA in respiratory samples from survivors for a median of 20 days after they became infected, they wrote in an article published in the Lancet medical journal.

The new coronavirus has spread to 118 countries and infected about 125,000 people since first emerging in Wuhan, China, at the end of last year, evading drastic efforts by local authorities and subsequent containment attempts in other nations.

The findings have “important implications for both patient isolation decision-making and guidance around the length of antiviral treatment,” Fei Zhou from the Chinese Academy of Medical Sciences and the other authors wrote.

Currently, the recommended isolation period after exposure is 14 days to avoid spreading the virus. But if people remain contagious long after their symptoms have vanished, they may unwittingly propagate the pathogen after they return from quarantine.

By comparison, only a third of patients with SARS still harbored the virus in their respiratory tract after as long as four weeks, the Chinese scientists said. They studied the medical records and laboratory data from 191 Covid-19 patients treated at Jinyintan Hospital and Wuhan Pulmonary Hospital, including 54 who died from the infection.

The drug, called remdesivir, had blocked the Ebola virus in laboratories and in animal experiments. But it did such a bad job extending survival in humans compared to two of the other treatments that researchers decided in August not to try it on any more patients.

Now the drug, created by pharmaceutical giant Gilead Sciences, is being tested in new clinical trials, and global health authorities deem it the most promising of possible treatments for people who are severely ill with the novel coronavirus, which causes the covid-19 disease. Because it is a “broad spectrum” drug that has been effective against multiple viral targets in the lab and in animals, the strategy could work, experts said.

The drug’s journey – from failing to prolong the lives of Ebola patients in sub-Saharan Africa just last year to being rushed into coronavirus clinical trials in China and the United States this year – symbolizes a dire lack of antiviral drugs that can fight emerging infectious threats.

As the outbreak spreads worldwide, a vaccine to prevent infection remains at least a year away. Meanwhile, there is no approved treatment to stop the virus once someone is infected, and the severe and sometimes fatal respiratory distress that afflicts a minority of patients.

The hope is that remdesivir will show better results with the coronavirus than it did with Ebola, which is from a different viral family, officials said. The first trial results could be available in April.

Gilead, the National Institutes of Health and Chinese health authorities are racing to test it on hundreds of people in controlled clinical trials, including a patient who was quarantined in Nebraska after being removed from the Diamond Princess cruise ship. Axios reported this month that Gilead acted so quickly that it did not even wait for required approval by the Food and Drug Administration before it shipped doses to China. Asked to respond, Gilead said it thinks its “limited shipments” were made in compliance with U.S. law.

“I just hope remdesivir works, because we really need a therapeutic that can intervene in this crisis,” said Richard Whitley, director of an NIH-funded research effort involving the world’s most dangerous viruses.

Gilead did not respond directly about the drug’s failure in the Ebola trial. “Covid-19 is a coronavirus that is unrelated to Ebola virus,” the company said. “Covid-19 is associated with different symptoms, pathology, and a different course of disease.”

Invented by Gilead about a decade ago, remdesivir has been proven to stop certain viruses from replicating in lab experiments and in animals. It has been researched in academic labs in North Carolina and Tennessee with backing from federal taxpayers since 2014, as part of a $37.5 million effort by NIH to find treatments for infectious diseases.

Until Monday, when it fell in a brutal market rout, Gilead’s stock price had defied the overall market decline of recent weeks, rising almost 20 percent from Feb. 21 to March 6, on hopes that the drug could provide the first treatment for covid-19.

The lack of treatment helps explain why. The stock price increased 5% on Feb. 24 alone when a top official of the World Health Organization pinned much of the world’s hopes for a treatment on the drug.

“There is only one drug right now that we think may have real efficacy, and that’s remdesivir,” said Bruce Aylward, WHO’s assistant director general. Ten days later, RBC Capital Markets gave it only a 50 percent chance of succeeding as a treatment.

The mixed signals have done little to dampen interest. There have been desperate pleas for supplies to treat patients on a “compassionate use” basis.

Although Gilead leads the pack on treatments, large drug companies such as Merck, Johnson & Johnson and Sanofi, as well as lesser-known companies Regeneron and Moderna, are pursuing coronavirus vaccines and medications, and executives estimate that at least 40 small biotech companies are developing drugs to fight it.

Every time there is a new virus, “we get started, but we don’t cross the finish line,” Julie Gerberding, a former director of the Centers for Disease Control and Prevention who is now the executive vice president and chief patient officer at Merck, said at a news briefing in Washington last week. This time, she said, industry is committed to pushing a vaccine to cross the line for regulatory approval.

“If we don’t cross it, it will be because it’s scientifically hard,” she said, “not because of the will or the investment.”

But drug companies also have been accused of not pursuing vaccines and antiviral treatments aggressively because the commercial markets for such drugs are weak.

The potential patient pool for clinical trials dries up once a new infectious outbreak subsides, so investment can be frozen in partly completed projects. And the pool of medical customers for a drug can be short-lived, if a seasonal epidemic quickly disappears, offering little chance to recoup an investment of what could be hundreds of millions of dollars.

Vaccine and treatment development tailed off after outbreaks of the earlier coronavirus cousins, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). The drug industry’s lobbying arm, the Pharmaceutical Research and Manufacturers of America (PhRMA), said that at least half of its members have mobilized in various ways to fight the new coronavirus in recent weeks.

“We need to encourage as many shots on goal as possible,” Stephen J. Ubl, PhRMA’s chief executive officer, told reporters.

Government efforts to spur development have produced sporadic progress. In the nearly 20 years since the SARS outbreak, the National Institutes of Health has spent nearly $700 million on research and development efforts around coronavirus, according to a survey by the advocacy group Public Citizen, which criticized the pharmaceutical industry for a “lack of interest that has left us lagging behind.”

Every epidemic presents uncertainty for drug companies, said Amesh Adalja, a senior scholar for the Center for Health Security at Johns Hopkins University.

“You never know how long it’s going to last. You never know what the market size is going to be,” he said. “Every conversation about price is when you’re in the middle of an emergency.”

Given the large degree of public financial support, debates are already flaring about how much Gilead should charge for its treatment if it ever makes it to market.

Congress and President Trump authorized up to $3 billion last week for efforts by academic researchers and drug companies to develop vaccines and treatments for coronavirus, part of an $8.3 billion emergency spending bill. The industry successfully opposed efforts by some House Democrats to attach guarantees for affordable prices for vaccines or treatments that result.

Gilead said it is too soon to discuss potential markets, in written responses to The Washington Post.

“We are focused on the potential clinical value that remdesivir may bring to patients and doing our part to respond to the coronavirus outbreak,” the company said.

Earlier testing of remdesivir has been performed by a partnership of university academics and the National Institutes of Health called the Antiviral Drug Discovery and Development Center, coordinated by the University of Alabama at Birmingham. It is focused on finding treatments for the family of coronaviruses, as well as Ebola, Zika, dengue and chikungunya.

Gilead said it donates free drug samples for the government-funded research of remdesivir and helps design scientific studies and clinical trials. Whitley, an infectious-disease expert who leads the drug development center in Alabama, credited Gilead for staying focused on fighting viral infections despite the poor market incentives.

“Drug companies don’t have an interest in emerging infectious diseases,” he said.

The public should not be excessively discouraged by the negative Ebola results last year, Whitley added. The trial in rural areas of Congo, a conflict zone with rudimentary conditions, was complicated by the fact that remdesivir’s correct dosage was unknown, he said. Also, it required a cumbersome daily IV administration, after being reconstituted from a freeze-dried form used for shipping in the uncontrolled climate conditions.

The drug has not been studied in human trials for SARS or MERS, because there are not enough patients, Gilead said.

“The number of clinical MERS infections was limited, with almost exclusive localization in the Kingdom of Saudi Arabia, and there were no SARS infections,” the company said.

In the new coronavirus outbreak, it said, it is reviewing individual requests from physicians to provide the drug on a “compassionate use” basis but only to patients who are hospitalized and showing “significant clinical manifestations.”