The COVID-19 pandemic has become the main medical event of our generation. We are continuously exposed in the media to the unprecedented impact that the coronavirus is having on our lives. There is an insatiable appetite to learn more about the virus, making science communication about virology more relevant than ever.
Some of the questions that scientists get asked the most are: 'Where did the virus come from?', 'How is it spreading?', and 'When will there be vaccines available to fight it?' A recent podcast by the Naked Scientists, entitled 'The coronavirus mutation situation', discusses how a better understanding of the genetic mutations of the coronavirus can be crucial in clarifying these questions. In this 25-minute podcast, presenter Phil Samson investigates this topic through a series of interviews with industry and academic researchers, with discussions ranging from the process of sequencing the virus to how coronavirus mutations can disrupt vaccine trials.
The first call Samson makes is to Dr Arinjay Banerjee, researcher at McMaster University, Canada who has been studying coronaviruses in bats for the last six years. His expertise in the field is invaluable in supporting a discussion on tracing the animal that infected humans with the coronavirus. For this purpose, he has been matching the human coronavirus with different animal variants, and identifying the closest match. However, the current database has insufficient information to find a good match with an animal, requiring both more animal and virus sequences. On top of this, I believe that there is another major limitation involved in this research. If we consider the extensive variety of animals that can be found at Wuhan's animal market, assuming that the virus came from there, the goal of this research is almost unreachable.
Based on a close match between the human and the bat coronavirus, Dr Banerjee strongly believes that the virus was found in bats, but these are not responsible for direct human transmission. Amusingly, a small domain in the coronavirus, which is required to enter human cells, is almost a perfect match with the pangolin virus. I found this very curious, especially taking into consideration that pangolins were not in the official inventory of Wuhan's market, although they are believed to be illegally sold due to their use in traditional Chinese medicine. To the listener's disappointment, though, Dr Banerjee concluded by suggesting that we may never know which animal transmitted the virus to humans, although bats and pangolins were probably involved at some point.
While the focus on bats and pangolins is interesting, it does fail to address a much bigger picture. The coronavirus has been demonstrated to infect many other animal species apart from bats and pangolins, and in some cases, human-to-animal infection has been strongly suspected. Infected animals may demonstrate no symptoms at all, which makes this investigation all the more difficult. And considering how different species interact, especially in wet animal markets like in Wuhan, transmission between animals is very likely. Given that we may never know which animal infected humans first, with several suspected animals, but no final verdict, this enigma might not ever be resolved.
The most interesting section of the podcast, for me, comes when Professor Richard Neher from the University of Basel, Switzerland discusses the open-source project Nextstrain, which he is co-building to track the evolution of the coronavirus in 'family trees'. He explains how, over time, an RNA virus acquires new mutations in its genome. The creation of a worldwide database of coronavirus sequences with small differences can be used to compare the sequences to each other. Then, through data analysis, researchers are able to trace back how these mutations arose and the common ancestor.
This database is potentially very useful, as it could help identify the way this virus spreads. For example, if sequence samples from the USA and Europe are very similar, this can suggest that someone has travelled between countries and transmitted the virus. Even more fascinating, though, is the fact that the virus no longer appears to come from a single location. This insight might be used to counteract the recent attempts to blame specific countries for the spread of the virus, showing that the virus never adhered to national borders.
This part of the episode therefore implicitly corrected some misconceptions in the public and policy debate about the virus. For me, it raised the question of how policy makers will use this data and whether they will interpret the results correctly. Although the use of large databases like Nextstrain could be very helpful, it is also very important for researchers to closely work with policy makers to analyse how previous infection control measures worked, and decide together how to move forward. The episode could have gone further in addressing how these scientific insights could inform policy-making, rather than just focusing on the science.
The next interview is with Dr David Matthews, a corona-virologist at the University of Bristol who researches the fundamental mechanisms of the coronavirus in monkey cell lines. Dr Matthews reveals that he has found two distinct viruses inside monkey cells, although only one virus had been inserted. While one virus was genetically identical to what it was expected to be, the other one had some genetic modifications. This second virus has been hypothesised to originate to infect the monkey cell lines more efficiently. These findings are presented as relevant limitations when developing vaccines, which are generally optimised and tested in monkeys before they are tested in humans during clinical trials.
Although this discovery is framed as a breakthrough for the listener, this is a common virological principle. Viruses continuously mutate over time in order to improve their efficiency and survival. This has supposed a significant barrier when developing virological vaccines, such as HIV vaccines, due to their high rate of mutation. Dr Matthews has simply confirmed that this virological principle applies to the coronavirus, and vaccine developers will need to be especially careful. Luckily for us, clinical trials are highly regulated and they tend to perform multiple screenings of the virus that would discard any variations that are developed by the monkey, and which could give raise to false results. Again, the episode here fails to sufficiently contextualise the findings; while the information itself is accurate, it thereby misrepresents its significance to a non-specialist audience.
While the episode benefits from a series of engaging interviews, this structure has several shortcomings. Not only does it start to get repetitive as interviewees repeat information, the lack of extrapolation by the interviewer, and the failure to contextualise the findings in relation to other research or wider policy implications, ultimately undermines the podcast's aim to inform public understanding of the coronavirus. The focus on the technical aspects of research was a welcome addition to the public debate, but scientific facts need to be explained and developed in relation to broader questions to be of use in any discussion or debate.