By Michael Le Page
Pharmacy employees in Shanghai, China during the coronavirus outbreak
Credit EDWIN REMSBERG, VW PICS / SCIENCE PHOTO LIBRARY
So far, around a quarter of people infected during the outbreak of a new coronavirus have developed severe respiratory infections, and around 3 per cent have died. With the numbers still climbing alarmingly fast, many groups are already rushing to try to find treatments for the virus.
A vaccine that stops people being infected by the new coronavirus would obviously be better than any treatment, but that is some way off. A vaccine would take at least a year, if not more, says virologist Jonathan Ball at the University of Nottingham in the UK.
The good news is that a few existing drugs might help save lives in the meantime. And new treatments could be developed in as little as six months.
There are two ways of treating viral infections. One is to find small molecules that stop viruses replicating by interfering with viral proteins. Antivirals are usually simple to manufacture, and can be taken in pill form, both big advantages.
But 99 per cent of potential small-molecule drugs fail, says Ball. So developing new antivirals from scratch could take years.
The second way is to use the same weapons our bodies use: antibodies. Antibodies are large proteins that bind to viruses and trigger their destruction.
When people are infected with a new virus, it can take two weeks for the body to produce enough antibodies to fight it off. Injecting people with antibodies made by cells growing in a vat can keep viruses in check until a person’s immune response kicks in fully.
Antibodies are less likely to cause side effects than small-molecule drugs, because they bind more specifically to viruses whereas small-molecule drugs tend to stick to lots of other things as well. This means we should be able to find safe and effective antibodies against the 2019 coronavirus very quickly the problem will be mass producing them fast enough.
In fact, a team in China has already tested antibodies against the coronavirus that caused the SARS outbreak in 2002, and found one that binds to the new coronavirus as well. But team leader Tianlei Ying at Fudan University told New Scientist it could take one or two months just to make enough of the antibody to start tests in animals and people.
There are two antibodies for treating the MERS coronavirus that have already been tested in people. The US biotechnology company that makes them, Regeneron, says they are unlikely to work against the 2019 coronavirus, but it will test them and others. While developing antibodies for Ebola, it took Regeneron six months to get to the stage where human tests could begin.
A Chinese company called WuXi Biologics announced in a press release that it is establishing a 100-strong team dedicated to developing antibody treatments for the 2019 coronavirus. It says it might be able to start mass production in a record four or five months.
By that stage there’s a chance the outbreak could be over or millions might be infected in which case making enough would not be easy. There are not many antibody factories, says Ball, and they are all already busy producing antibodies for treating cancer and other diseases.
There might be a shortcut. Instead of making antibodies in a vat, a US company called RenBio instead injects the genes coding for them into leg muscles. Antibody production in the body continues for weeks or even months, so these injections could be given to people to prevent infections as well as treat those who are already infected.
Both are possibilities, says the head of RenBio, Neal Padte. But this has only been tested in animals, so health authorities may be reluctant to try it.
There are a few existing small-molecule drugs that might help. For instance, an experimental antiviral called galidesivir developed for treating Ebola is active against coronaviruses, says its US maker, BioCryst Pharmaceuticals. It has already passed safety tests in people.
The company is in active dialogue with relevant US public health authorities to ensure that galidesivir is available to them, says John Bluth at BioCryst, though he did not say how fast production could be ramped up.
Most promisingly, two drugs given together to treat HIV called lopinavir and ritonavir are already approved for human use, and in small trials they seemed to reduce disease severity and fatalities in people infected by the SARS or MERS coronavirus.
Doctors in Wuhan, the centre of the outbreak, have already started a randomised controlled trial of lopinavir and ritonavir. Given the scale of the outbreak in China, you would hope to get a reasonably quick answer to whether these interventions work, says Ball. The manufacturing for these is already in place and they are easily available.
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By Michael Le Page