Coronavirus: quarantine, spread, and a potential vaccine
The new coronavirus from China has continued to dominate the headlines. This week, Chris Smith examined the world's response to the disease now called "Covid-19". He heard about its likely spread to date from epidemiologist Freya Jephcott, and about a proposal to develop a vaccine from pathologist Jonathan Heeney - but first, he spoke to one of the initial 83 UK citizens evacuated from Wuhan and quarantined near Liverpool...
Kharn - My name is Kharn Lambert. I'm a PE teacher and living in Wuhan, China, and I'm currently in quarantine in The Wirral. We were evacuated by the British government two weeks ago.
Chris - Have you seen much of the action when you were in Wuhan?
Kharn - Yes, there was a lot of activity going on while I was there. People being taken to hospital. A lot of overcrowding in hospitals, people fighting to see doctors, people fighting to get food when the foods were running low.
Chris - Were you scared?
Kharn - On a personal level, I wasn't scared. My biggest worry was my 80 year old grandmother who suffers with COPD [Chronic obstructive pulmonary disease] and was visiting me in Wuhan and got caught up in all of this.
Chris - And what was it like when you actually got evacuated? How did that play out?
Kharn - It was chaos. We got a phone call about an hour and a half before we had to be at the airport. I mean, we wasn't fully prepared because we wasn't expecting to hear till the following day. We were waiting around for four or five hours in the cold at the meeting point because they kept pushing it back. And then once we got inside the airport, chaos! I mean there was no real organisation. Flight tickets were blank with just a simple number on them. Nobody really knew what they were doing until we got on the flight actually. And then once we were on the flight, you know, the stuff were fantastic with us.
Chris - And when you touched down, apart from the enormous sense of, Oh, I've finally made it home, what happened next?
Kharn - It's a massive sense of relief once we touched down in Brize Norton, but then we were obviously ferried onto buses and transported with police escorts up to The Wirral.
Chris - And how are they keeping an eye on you? As in, I don't mean as in policing that you're there, I mean, as in from a health point of view.
Kharn - At the very beginning they were doing checks three times a day that we felt okay, that we weren't showing any signs or symptoms. They didn't actually test us at any point because I think the advice from public health England was that it's pointless testing anybody that's not showing any signs or symptoms because it just wouldn't show on the test. They have since changed that advice. And so we were tested for the first time yesterday, and we're just waiting for those results to come through.
Chris - And what about your future? Because if you work in Wuhan, are you on the next plane back out there?
Kharn - No, I'm not on the next flight. Obviously the airport in Wuhan is closed. I can't get back into Wuhan now until these restrictions that the Chinese government have put on Wuhan are lifted. So I don't expect to go back to China for another four or five months, maybe even six months.
Chris - What does that mean for your job then?
Kharn - Thankfully I work for a very reputable school in Wuhan, so my job is safe; and all of the expats that work there, their jobs are safe.
Chris - Is the school still open? Or is basically everything off?
Kharn - No school is actually closed, but they did start online classes yesterday.
Chris - You're not going to do some exercise classes online then?
Kharn - No, it's a little bit difficult to do that. I think I've got a bit of a lucky break on that respect!
Chris - Wuhan city PE teacher and ex-coronavirus quarantinee Kahrn Lambert. One of the other major developments this week was a sudden apparent surge in the numbers of people reported by China to have the infection. In one day, the rate of diagnoses increased almost tenfold. This, China explained, was because they'd altered the way they were diagnosing the disease. So what might be the implications of these much bigger numbers of cases?
Freya - My name's Freya Jephcott and I'm a research fellow at the University of Cambridge where I study outbreaks of unknown etiology. Obviously the size of the outbreak has grown significantly and that's because of how transmissible this virus looks to be. Even with some of the quite extreme control measures that have been put in place in China. I think what's interesting though is whilst the numbers have increased steadily within China, we're still only seeing limited cases in other countries.
Chris - Do you think that's real or do you think it's a symptom of the fact that when you go looking you find and if you don't look, you don't get the answer to a question you don't want to ask?
Freya - Oh, I think that's the big question here. I would say considering what we know about the virus and actually a lot of what we don't know about the virus such as, when people are infectious, if it's before they've developed symptoms, if it's after, I would think that probably there is some unobserved transmission going on in some other countries.
Chris - Now, China this week have changed how they define a case. Does that tell us anything about the real numbers that are probably happening in China and therefore anything about what's probably happening elsewhere around the world?
Freya - This one is quite interesting because obviously now that it's a broader case definition, we're going to be capturing a lot of other cases that previously were being missed. It's unclear if the reason that testing wasn't a good enough proxy by itself is because the testing was giving uh, negatives when it shouldn't have, or there weren't enough tests or they could only run so many a day. But this looks like a reasonable way now of getting a broader sense of it, and potentially also capturing some of the milder cases too that might've been going under the radar previously. It will actually give us a better sense of actually how many people do develop severe illness from this and how many go on to die, which could be smaller than was initially thought.
Chris - And given these very big numbers being reported in China, one therefore must presume that there were big numbers previous to now as well. What does that say about the likelihood of it already being in countries like this one?
Freya - So it's unclear because they did create quite strong lockdown measures quite early on, but it does mean that probably some people were acting as if they thought they were negative and perhaps interacting closely with friends and family anyway, including outside of the areas that were locked down, which could have well led to more of this unobserved transmission to other countries.
Chris - Freya Jephcott. Also this week, scientists were racing to file bids for funding announced as part of an emergency response program to bankroll the development of vaccines against the new coronavirus. One of the applicants was Cambridge University's Jonathan Heeney. His team have developed a system to enable them to produce vaccines based on the genetic material of the virus.
Jonathan - Coronaviruses are named after what they look like: round spherical objects with these little... what we call spike proteins.
Chris - Those spikes are how the virus docks with and invades our cells. So an effective vaccine has to produce antibodies that can block them, but that's actually easier said than done.
Jonathan - Because if you make antibodies to the spike, actually those antibodies can help drag this virus in a monocyte-macrophages, a very important inflammatory cell that can be reprogrammed by these viruses making the disease much more severe than it would be.
Chris - So an ill conceived vaccine could potentially pour fuel on the microbial fire and accelerate the infection, paradoxically making the person even more ill than if they'd never been vaccinated.
Jonathan - So the vaccine strategy really has to be laser specific, targeting those domains that actually are absolutely critical for docking with a cell. That's this new technology that we've developed.
Chris - What their technique allows them to do is to screen using a computer model of the virus structure all of the components of the viral coat, including those spikes that it uses to get into our cells, to find the crucial pieces that will work as a vaccine and disable the virus, but without the risk of making the infection worse.
Jonathan - This is a computational approach where we take the genetics of these viruses and we target those essential elements in a laser guided missile type of way so that the antibodies attach only to those regions that is important for docking.
Chris - The result is a piece of the viral genetic code that the virus uses to produce that part of its coat. This genetic sequence can be injected into the body where immune cells pick it up, decode it, and then use the information to educate the rest of the immune system to produce antibodies against that discrete part of the virus. But how long, crucially, is this going to take?
Jonathan - It has to then legally be manufactured in such a way that the regulatory authorities will allow it to go into humans. It needs to go for a separate safety and toxicity testing. That will take four months.
Chris - Is this going to arrive on the scenes fast enough to make a dent in this outbreak?
Jonathan - I think so. I think the cat is out of the bag, meaning the virus is out of China. The Chinese are having great difficulty containing it. This virus has changed the rule book, people actually who are not overtly ill sometimes don't even have fever yet, can be contagious. So it's a different game. We do need to move quickly, but the golden rule must be do no harm. Meaning don't be in a rush to make something that's gonna make the disease more severe.