Skip to 0 minutes and 11 secondsMARTIN HIBBERD: I want to talk about how this novel coronavirus was identified, and sequenced, and how that led to new diagnostics.
Skip to 0 minutes and 23 secondsWell, there's a number of ways which can these can be investigated and we've had experience of doing this many times as scientists. I was involved with the SARS coronavirus doing this. But in Wuhan, China what they did is that they took clinical material from the patients. It's a lung wash is what they used to start this. That material was put into the tissue culture to see whether you could identify the virus. The same material was also used in standard molecular assays, or multiplex PCR-type assays, and this allows us to look for all the common types of viruses. But also we look for generic ones, so we included a set of primers which could detect coronaviruses in general.
Skip to 1 minute and 8 secondsAnd, finally, some of the material was put into the deep sequencing. So this is the new generation of sequencing which allows you to do very large sequencing jobs and look unbiasedly at the material and see what can be discovered in that process. All of these approaches gave the same answer which is a little bit unusual as a scientist actually. But they all gave the result as a novel coronavirus that came out from this, even the electron microscopy that looked at the virus looked a little bit different from the average tissue culture also gave slightly different effects from what was expected. The PCR multiplex molecular assay also gave a generic coronavirus and none of the specific ones.
Skip to 1 minute and 56 secondsAnd then the deep sequencing identified the whole genome of a coronavirus, which looked somewhat similar to other bat coronaviruses which was also distinct. And from all of this we were able to identify that this was a novel virus for humans.
Skip to 2 minutes and 17 secondsSo this work was all done in Wuhan, China and also with-- in Beijing-- the CDC group there-- and effectively done in January 2020, so very soon after the first cluster of cases were done.
Skip to 2 minutes and 39 secondsFrom the genome sequence we were able to identify the novel regions of the genome and also, therefore, develop new molecular diagnostic tools from that. And certainly in China that was done within just a few days and that was-- allowed the diagnostics which everyone is using. But because the genome was published, actually all the other CDCs around the world also developed their own primers. And some of those overlap, some of them are similar. But because there's a diversity of locations across the genome in fact there are now several different assays which can be used to confirm each other. So this was a huge aid to the rest of the world.
Skip to 3 minutes and 22 secondsAnd these diagnostic assays could be produced outside of China and around the world.
Skip to 3 minutes and 34 secondsWell, as I mentioned, it's a very fast process once you have the genome. The looking at the molecular assays is a matter of designing the primers and putting that into a standard type of assay and that can be done in a few days. Of course, we're all hoping for the much simpler and easier to use point-of-care diagnostic and I'm hoping that that might become available, but the technology for that is a little bit more challenging. We are also hoping that we might be able to get serology-type of assays that's looking at the immune response, the antibodies to the virus.
Skip to 4 minutes and 12 secondsAnd that test would also allow us to have a second analysis to allow the diagnosis, but also might give you some history of whether you've had the disease in the past. And, additionally, this type of assay is the more commonly used one for point-of-care diagnostics. So there's some hope that we might be able to improve the diagnostics in time.
How was the novel coronavirus identified?
Professor Martin Hibberd discusses here how the new coronavirus was identified and sequenced, and how this has led to diagnostic tests (recorded 25th February 2020).
Intended learning outcomes
- Describe the process that led to identification of the novel coronavirus
- Explain the process of identification using whole genome sequencing
- Explain how the initial PCR diagnostic was developed
For technical language explainers please see the “See Also” links below.
© London School of Hygiene & Tropical Medicine 2020