Coronaviruses have caused three outbreaks in humans in the past 20 years: they were responsible for SARS in 2002, MERS in 2012, and the ongoing outbreak spreading rapidly through China and around the world. While finding ways to prevent and treat this new virus is the most pressing priority, in the long term, scientists have their eye on ways to prevent and treat any coronavirus — so that they’re prepared for the next one to come along.
“This is not a one-off,” says Timothy Sheahan, a coronavirus expert and assistant professor at the University of North Carolina Gillings School of Global Public Health. “This is something that will continue to happen in the future.”
The new coronavirus is a dangerous public health problem for China and the rest of the world. But having another iteration of these viruses jump to humans does give scientists another important piece of data as they work to figure out treatments for this family of viruses. Coronaviruses circulate regularly in wild and domestic animals, but there’s a lot unknown about the properties that make them able to infect people. “The best information we have is to see which viruses end up being human coronaviruses and which are not,” Sheahan says. “Every time one of these jumps, it gives us another piece of that puzzle.”
The ongoing outbreak also lends urgency to ongoing coronavirus work, and shows how important it is. Sheahan works on projects funded by the National Institute of Allergy and Infectious Diseases to identify antiviral drugs that can treat coronavirus infections. In the past few years, the teams have honed in on a drug called remdesivir, an antiviral developed by the pharmaceutical company Gilead Sciences. That drug was tested in humans as a treatment for Ebola in 2014 and 2015, and was found to be safe, even though it didn’t work well against that disease.
“It’s a broad-spectrum antiviral, and it can work against a host of genetically unrelated viruses,” Sheahan says. In cells, it can block SARS, MERS, and other coronaviruses found in animals. In mice, it’s been effective in fighting off SARS and MERS infections.
Just because remdesivir works in mice doesn’t mean it would work in humans, but it’s already been given to people during Ebola trials and health officials think it’s safe — so it could more rapidly be tested in patients who have the new coronavirus. Gilead said it would provide the drug to patients with the new coronavirus through compassionate use “where appropriate.” Remdesivir has not been approved by any regulatory bodies.
There are other options for coronavirus treatments too. Back in 2003, preliminary studies showed that the combination of two antiviral drugs used to treat HIV, lopinavir and ritonavir, was effective in patients with SARS. Testing halted as the SARS outbreak subsided, but now the drugs are being tested in patients with the new coronavirus.
“There could be universal antivirals against coronaviruses. There might already be one,” says Florian Krammer, a professor and vaccine development expert at the Icahn School of Medicine at Mount Sinai. “Over time, we could have an even better one.”
While an antiviral to treat coronavirus infections is tantalizingly in reach, creating a vaccine that could protect against any coronavirus — even before people get infected — is a bigger task. First, scientists need to develop a vaccine specific to the new coronavirus, Krammer says. “It doesn’t matter if it’s broadly protective,” he says. The important thing is stopping the spread of the current outbreak. “But in the long term,” he adds, “it would be good to have something that helps against any kind of coronavirus that comes along.”
A universal coronavirus vaccine isn’t impossible to imagine. Most coronaviruses have a bit of protein on their surface that they use to latch on to the cells they are infecting, and they bind to the same receptor on those cells’ surfaces. That’s a possible target for vaccine development, Krammer says.
However, it could take years to create that kind of vaccine. Scientists have been working towards a universal flu vaccine for over a decade, and candidate drugs are only just entering early-stage clinical trials to test if they’re safe and work in humans. Efforts to develop a coronavirus vaccine would run into some of the same problems faced in the flu research. Those efforts, though, would benefit from the experiences of researchers working on the flu. “A lot of the arsenal of weapons we have now could be used for coronavirus,” Krammer says.
Treatments for active coronavirus infections and preventative tools like vaccines are both important public health tools that could help manage any new viruses that emerge in the future. A drug that could be quickly deployed in the event of an outbreak would address an immediate need, while a universal coronavirus vaccine could provide extended public health protection, Sheahan says. “They’re the short-term and the long-term goals.”