Understanding Covid-19 – a virologist’s view
Dr Elisabetta Groppelli is a Lecturer in Global Health at St. George’s, University of London. Her Foundation-funded project examines how the Hepatitis A virus hijacks and infects cells, to understand how infection spreads through the body.
However, since the Covid-19 outbreak began in January, Elisabetta has been contributing her expertise as a virologist to the pandemic response. She has also used her @ViralRNA Twitter account to communicate the latest scientific evidence for her followers, and translate insights from the situation in Italy, where she is originally from.
We spoke to Elisabetta about the latest Covid-19 research into diagnostic tests and potential treatments, and ‘the only weapon we have right now’ for fighting the pandemic: social distancing.
“There are two main things we would like to do – one is really understanding the virus, and the second is doing the things that are urgently required right now in order to save lives.
“Where I come in is the molecular biology, particularly surrounding the tests we’ve been hearing about. The reality is, these techniques are used by people like me every time we want to know where the virus is – it could be a patient sample or cell culture: we disassemble the virus and use a very specific method to look for the viral RNA genome.
“RNA is a molecule similar to DNA. We (and most organisms) store our genetic information in DNA and then make a temporary copy of it in RNA. Think about having a recipe book (DNA genome) and making a photocopy (RNA) of the page of the food you want to cook. However, some viruses, like the coronaviruses but also Hepatitis A virus, use RNA both for the book and the photocopy. Because I’m a virologist who has always worked with RNA viruses, I’m familiar not just with the molecular testing pipeline, but also with the type of virus and the type of genome.
The clinical trials are not only hugely important for the answers they can give in a few weeks or months, but also because they involve collecting samples from patients with an ongoing infection. These samples are invaluable because they allow us to study both the virus and the human response as they happen in real life, as opposed to how they happen in the artificial context of the laboratory. Dr Elisabetta Groppelli
“The test itself is quite difficult because it is the top-end test we can do in a diagnostics lab, requiring quite skilled personnel and advanced equipment. RNA is also a very fragile molecule, so you really need to be careful about handling it. And of course, all of this is complicated by the fact it is a respiratory virus for which we have no treatment or vaccine, so the levels of containment required are high. All of this makes the test quite difficult and comparatively slow, and we’ve seen that many countries can’t do as many tests as they would like.
“Where I come in is providing the test for non-diagnostic purposes. For drugs clinical trials, you want to see what happens to the virus over time, comparing people who have received treatment with people who haven’t. At the moment, the diagnostic tests only tell you whether someone has the virus or not. I’m setting up the tests so that it can give us the concentration of the virus, not just if it’s there or not but how much there is. So, for example, is there a smaller amount of the virus if we use this particular treatment?
“Funders of medical research are focusing on what is going to have the biggest impact right now, for example by screening drugs that have already been approved for clinical use, and seeing whether they can be repurposed for Covid-19. An example of this is the national Recovery trial, which I’m contributing to from a diagnostics perspective.
“Right now, I’m very much focusing on research that is less fundamental and more based on treatments. The other pressing matter at the moment is actually collecting samples. The clinical trials are not only hugely important for the answers they can give in a few weeks or months, but also because they involve collecting samples from patients with an ongoing infection. These samples are invaluable because they allow us to study both the virus and the human response as they happen in real life, as opposed to how they happen in the artificial context of the laboratory. So, at St George’s we’re also collecting samples that we plan to analyse from the antibody response point of view, but also from the viral RNA genome point of view: by comparing the genomes of the virus in our samples with the genomes that have been isolated and sequenced all over the world, we can look back on what happened and try to find out where the virus comes from and how it has spread in our community and the world.
“Despite all of this research activity, which holds great promise, social distancing is still clearly the only weapon we have right now to stop transmission. It’s fantastic that we are looking at vaccines and testing, but the reality is right now, for the next few weeks, the only thing that is going to have an effect is social distancing and the restriction of movement.
“Each and every one of us needs to be doing it. A small minority not adhering to the measures can actually have a major effect. We know it’s disturbing and distressing from a human point of view, but as a virologist I’m happy when the streets are empty, as that’s what’s needed. Every little interaction, every step we take can have a great effect in either direction, and we need to shift in a positive direction.
“The virus goes from one person to another. If you put two people far away, the virus will land in between, and therefore there’s no transmission of infection. This is the fundamental answer to the biology of the virus.”