The question on everyone’s mind is: When will the COVID-19 crisis end so we can we get back to normal?
The answer, experts said, depends largely on the virus itself, whose behavior and prevalence scientists are still struggling to understand.
The virus, which first emerged in China less than four months ago, is so new that “in terms of its trajectory, we don’t have enough data yet,” said Barun Mathema, an assistant professor of epidemiology at Columbia University and an infectious-disease expert.
One of the key unknowns is if COVID-19 is, like the flu virus, seasonal, and whether its spread will slow as temperatures rise.
“I wouldn’t put too much hope it will die out,” said Jaymie Meliker, an epidemiologist and professor of public health at Stony Brook University. “It may get a little weaker. It’s hard to say.”
A report Wednesday from the National Academies of Sciences, Engineering and Medicine found that although some lab studies on the virus and reviews of worldwide prevalence indicate it may spread more slowly in warmer temperatures, the data is limited and inconclusive.
The virus could potentially remain active for years, although “viruses tend to mutate and change over time, just like influenza is technically a different virus every year,” said Dr. Adam Berman, associate chair of emergency medicine at Long Island Jewish Medical Center in New Hyde Park.
As with the flu virus every year, a mutated COVID-19 could be either more or less dangerous and infectious than the current virus, Berman said.
In the 1918 influenza pandemic, which killed about 675,000 Americans and at least 50 million people worldwide, there is evidence the virus mutated between the spring and fall of 1918, becoming much more aggressive, before mutating again and becoming less aggressive, Meliker said.
As a coronavirus, COVID-19 belongs to a different family of viruses than influenza. Another coronavirus, SARS, which emerged in late 2002 and killed hundreds, died out in 2004. It was less contagious and more deadly than COVID-19, “and by killing people a lot quicker, it didn’t circulate as much,” Meliker said.
Unlike with SARS, many who carry COVID-19 are asymptomatic, and they walk around in public not knowing they are potentially transmitting the virus to others, he said. Half of those with the virus who were part of large-scale testing in Iceland are asymptomatic, he said. The U.S. Centers for Disease Control and Prevention puts the asymptomatic estimate at up to 25%. It’s unclear why a virus that is so deadly for some people does not cause symptoms in others, he said.
The limited testing in the United States — even many people with symptoms cannot get tested — means no one knows how many people carry the virus, Meliker said. In New York, nearly 190,000 people had tested positive for COVID-19 as of Sunday, but the real number of people who are or were infected statewide could be more than 1.8 million, he said, when those who haven’t been tested are added.
Social distancing helped slow what had been a rapid growth in the number of cases, but with so many people already infected, if social distancing and other restrictions were completely lifted too soon, he said, “I would guess it would start growing exponentially again within a week or two or three of opening the economy.”
Allowing the virus to sweep through the population could eventually end the spread, because those who survived likely would be immune from getting sick again, but “if it goes through the whole country very quickly, that would be devastating,” Meliker said.
An eventual limited easing of social distancing that mitigates the economic havoc the restrictions have caused — such as allowing gatherings of fewer than 50 people and still requiring people who can work from home to do so, while permitting others to return — would lead to an increase in cases, but “in a slower and more controlled way, so we’re not overwhelming the health care system,” Meliker said. The most vulnerable, such as elderly people, would need to remain isolated.
Researchers are testing potential vaccines against the virus, although the earliest it would be widely available would be at least a year from now, experts said. But “it’s not a given that we will get one,” Yonatan Grad, an assistant professor of immunology and infectious diseases at Harvard University, said in a media conference call Thursday. Despite decades of research, there still is no vaccine for HIV.
Antibody testing could be part of policymakers’ lifting of some restrictions, Meliker said. Those with antibodies that would likely protect them from getting sick from the virus again could go on with life as normal, while those without antibodies could still face restrictions, he said.
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said Friday on CNN that two federal agencies are validating antibody tests, to ensure they are accurate and consistent, and a number of tests may be available within a week.
But, Meliker said, “The thing with antibody testing is we have to keep doing it every few weeks or months” because people will continue to get infected and then create antibodies.