At the stroke of midnight on Wednesday, the skies above China’s Wuhan brightened as towers along both sides of the Yangtze River lit up in tribute to the health workers who helped the city of 11 million curb a deadly outbreak of the new coronavirus.
Cheers of “My Wuhan is back” and “Wuhan, let’s go” rang out on the embankments as bridges and highways opened up for the first time in 76 days, allowing people to leave the industrial hub and epicentre of China’s coronavirus epidemic.
Beijing sealed off Wuhan on January 23, confining millions to their homes in an unprecedented bid to contain the virus, officially known as SARS-CoV-2 and first detected among workers at a seafood market in the city.
At the time, many saw the quarantine as an extreme and draconian measure. But as the virus spread across the globe – infecting more than 1.6 million people, killing more than 95,000 of them and overwhelming healthcare systems in some of the world’s most developed nations – other governments also followed suit, imposing extraordinary curbs on movement and social contact.
Now Wuhan’s reopening is offering hope to billions of people chafing under lockdowns, wondering when life will return to a semblance of normality.
Officials and experts are urging caution, however.
“China has brought the situation under control. But that may be just for now,” said Yanzhong Huang, senior fellow for global health at the United States-based Council on Foreign Relations. “There is a real risk of resurgence of cases. For two reasons – the prevalence of asymptomatic people who might spread the disease without knowing they are sick and the threat from imported cases.
“Chinese scientists and decision-makers have no idea of the size of asymptomatic carriers and to what extent they pose a danger to the population in the country. The threat of imported cases is also a concern given that most people in China have not been exposed to the virus and therefore, are yet to build immunity to it.”
With a vaccine at least a year away, the world faces an “uphill battle”, said Huang, explaining that any one country or region’s success in containing the disease was shaky so long as the pathogen continues to sicken people elsewhere.
In just three months, SARS-CoV-2 has reached 184 countries and territories, and although the virus emerged in mainland China, Beijing now ranks fifth among countries with confirmed cases, reporting more than 82,000 cases, including more than 1,000 asymptomatic cases and 3,000 deaths. Italy has the highest number of fatalities among the affected countries, recording more than 18,000 deaths, while the US has the most number of infections with more than 460,000 cases and 16,000 deaths.
“You cannot claim the pandemic is over until all countries can say they are virus-free,” Huang said.
That portends a long period of intermittent lockdowns for the world, with governments tightening and easing controls as infections surge and fall, as well as continued restrictions on international travel – until a vaccine is found or enough of the world’s population develop immunity through infection, a concept known as herd immunity. And that too, if the virus remains stable without significant mutations that may make it more virulent.
Scientists say the public health threat the virus represents is the most serious seen in a respiratory virus since the 1918 influenza pandemic, in which as many as 100 million people died across the world.
Known as the Spanish Flu, the disease hit in three waves said John M Barry, a historian who studied the 1918 pandemic.
“A mild first wave in the spring, a very lethal second wave which ran roughly from September to December, and a third wave, lethal but not nearly as bad as the second wave,” he said, explaining the pathogen mutated and became more virulent in the second one.
“Fortunately there is no evidence, no hint anywhere, that [SARS-CoV-2] will be any more dangerous than it is now,” he said, adding: “I would expect to see several waves extending for a year or more, each one with a flatter peak and easier to handle.”
Scientists at the Imperial College in London, United Kingdom, suggested the severity of a second wave of coronavirus infections may depend on how many people were exposed to it in the first outbreak. The more successful countries or cities are at containing the virus, “the larger the later epidemic is predicted to be in the absence of vaccination, due to lesser build-up of herd immunity”, they said in a study published last month.
“Intermittent social distancing – triggered by trends in disease surveillance – may allow interventions to be relaxed temporarily in relative short-time windows, but measures will need to be reintroduced if or when case numbers rebound,” they added.
These findings are substantiated, at least in part, in the experience of countries and cities across Asia, which seemed to have the epidemic under control early on, only to impose stricter measures amid a surge in infections tied to travellers arriving from hotspots elsewhere, most notably in Europe.
Singapore, one of the first countries outside China to report a coronavirus case, initially managed to control its outbreak without resorting to lockdown measures. The city-state relied on a strict surveillance and quarantine regime to keep infections in check. But last week, it closed schools and workplaces as the number of cases surged above 1,000 – many of the recent cases were linked to migrant workers.
In nearby Hong Kong, a semi-autonomous Chinese territory, authorities tightened border controls with the mainland and told civil servants to work from home soon after detecting its first case in late January. Workers returned to their offices in the first week of March as the outbreak subsided. But weeks later, they were told to go back home amid a spike in infections linked to overseas travellers.
In recent days, the territory has banned public gatherings of more than four people, closed its airport to foreign arrivals and shuttered some bars and restaurants.
Meanwhile, Japan, which now has nearly 5,000 cases, declared a state of emergency on Tuesday as the government sought to obtain more powers to press people to stay home and businesses to close.
China, too, barred most international travellers in late March over worries they may trigger a new wave of infections.
“I anticipate there will be significant disruption to international travel for at least the next three months, and likely even longer if countries are unable to sufficiently stamp out community transmission,” said Teo Yik Ying, dean of the Saw Swee Hock School of Public Health at the National University of Singapore.
“While there are encouraging signs emerging from some of the worst-hit countries in Europe, the reality is there are countries in South and Southeast Asia, Africa, and also Latin America that are starting to see community transmission. This means, any attempt to relax border restrictions can result in importations that go on to seed the second wave of community transmission. As such, countries will naturally exercise caution before they allow trans-national travel.”
Dr John Nicholls, clinical professor in pathology at the University of Hong Kong, agreed with that assessment.
The scientist, who is studying the effects of temperature on SARS-CoV-2, said the virus was sensitive to temperature, surviving and transmitting better in colder weather. That would give countries in the northern hemisphere a respite from the virus in the coming summer months, but it means “the worst is yet to come for countries in the southern hemisphere”.
“So don’t expect international travel for next few months, or even longer,” he said.