It has been more than a month since the World Health Organization declared the novel coronavirus a public health emergency of international concern. Since the outbreak began, there have been more than 90,000 cases of the virus worldwide and more than 3,100 deaths from it.
As officials work to stop the virus’s spread, it is hard not to wonder what will happen next. When and how will this end? Here’s a look back at what happened during other infectious outbreaks.
Scientists often intervene during infectious outbreaks with vaccines and antiviral medications.
That was the case in 2014 when an outbreak of Ebola virus in West Africa concluded with strains being “interrupted,” the World Health Organization said in March 2016. The outbreak ended after a “coordinated international response,” said Dr. Peter Hotez professor and dean for the National School of Tropical Medicine at Baylor College of Medicine.
When another outbreak began in 2018, two treatments developed from the first outbreak were offered to all patients in the Democratic Republic of the Congo.
“Both times human intervention made the difference,” Hotez said, adding that the same could be true for coronavirus. Currently there is no vaccine and no specific antiviral treatment recommended for the novel coronavirus – but many are in development.
“I’m pretty optimistic we are going to have a good antiviral drug and protocol in the coming weeks and months,” he said.
More than 20 coronavirus vaccines are in development, according to Tedros Adhanom Ghebrevesus, director-general of the World Health Organization. The first clinical trial of an antiviral drug is underway.
While Hotez’s team is among those working on a vaccine, he said he is not optimistic it will come in the time frame of this outbreak. First, the vaccines must get into clinical trials, then they must get approved, and with the amount of scrutiny in vaccine safety testing, he said, it is not likely one will be available to the public in time to curb this outbreak.
The SARS outbreak was brought to an end in July 2003 by good hygiene practices – such as frequent hand-washing – and environmental factors such as high temperature and humidity in the summer months, said John Nicholls, clinical professor of pathology at the University of Hong Kong (HKU).
SARS is another strain of coronavirus that infected more than 8,000 people in 2003. By May of that year, it was burnt out, said Dr. Howard Markel, director of the Center for the History of Medicine at the University of Michigan.
How does an outbreak “burn out”? Sometimes, Markel said, it’s because the weather changes and sometimes it is because enough people have been infected and become immune.
“If I had to predict, I would say very likely by May or June or July this will burn itself out,” Markel said.
But, that doesn’t mean it would be gone for good.
Outbreaks can change as the seasons do.
The H1N1 flu strain caused a pandemic in 2009, and now it has become a seasonally occurring virus.
Seasonal viruses can be seen year-round, but in the Northern Hemisphere cases tend to peak in the colder, winter months and fall when it gets warm, Hotez said. There isn’t a clear understanding of why that is, he said, but the humidity levels and time spent huddled indoors are possible reasons.
Whether coronavirus will reoccur is anyone’s guess, Hotez said. There just isn’t enough evidence or enough time to make a good prediction.
More certain is that this coronavirus outbreak revives lessons learned from the outbreaks before it, Hotez said.
There is a bumpy road at the start and then authorities regroup as they learn how the pathogen behaves and is transmitted to vulnerable people.
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The most common resolution is a “global amnesia,” Markel said. The virus winds down and the public goes back to their regular lives, not thinking about the outbreak.
But that may be a problem. Instead, Markel said, people should remain vigilant and prepared.
“The lesson is that we are living in a new age of infectious disease, and they are going to rear their ugly heads on a regular basis,” he said. “The lesson we are not learning is that we need to be prepared for this.”