For those keen to dig a little deeper and find out more about Covid-19 mutations, herd immunity and the science behind it all…
Where to start?
To learn more about Covid-19 variants the best first step is to dive into the extensive bibliography of plagues and pandemics – in which mutations have generally played an important role.
The best book on the 1918 pandemic is Laura Spinney’s Pale Rider: The Spanish Flu of 1918 and How it Changed the World (2017). Mark Honigsbaum’s The Pandemic Century: A History of Global Contagion from the Spanish Flu to Covid-19 (2020) brings the story up to date, while Unprepared: Global Health in a Time of Emergency (2017) by Andrew Lakoff tracks the strategic failure to prepare for an outbreak of this sort. Broader surveys can be found in William H. McNeill’s Plagues and Peoples (1998 edn.), Michael B. A. Oldstone’s Viruses, Plagues & History: Past, Present, and Future (2010) and The Great Leveller: Violence and the History of Inequality from the Stone Age to the Twenty-First Century (2017) by Walter Scheidel.
On evolution and the way in which viruses mutate, start with Richard Dawkins’ classic The Selfish Gene (40th anniv. edn, 2016), Luis P. Villarreal’s Viruses and the Evolution of Life (2005) and Viruses: A Very Short Introduction (2018) by Dorothy H. Crawford.
Jared Diamond’s Guns, Germs and Steel: A Short History of Everybody for the Last 13,000 Years (2017 edn.) also addresses the way in which pathogens mutate, as do Michael T. Osterholm and Mark Olshasker’s Deadliest Enemy: Our War Against Killer Germs (2017) and Adam Kucharski’s The Rules of Contagion: Why Things Spread – and Why They Stop (2020).
In this week’s audio essay, ‘March of the Mutants’, Matthew d’Ancona revealed that coronavirus variants are currently the single most important factor determining government policy and our chances of returning to normal life.
Once known as the “Garden of England” for its abundance of orchards and hop gardens, Kent’s reputation has taken a bruising in recent months thanks to B.1.1.7 – the variant first detected there. Of course, as we learnt quickly, Charles Darwin’s theory of evolution is no different for viruses. Both Rupert Beale in the London Review of Books and William Haseltine for Forbes offer a good series of articles on variants.
For more on the science, this research paper covers the transmissibility and impact of the Kent variant. Harvard’s Stephen Kissler has also written a paper that is a useful reference for those keen to get to grips with the detail.
And if you’re interested in a breakdown of the data across all variants, the US Centers for Disease Control and Prevention’s live interactive map lets you track cases of variants across the globe.
Not only have we been threatened by new variants but we’ve also seen a “recombination” event, whereby two variants have joined forces – the Kentish version and a new Californian flavour. Graham Lawton in the New Scientist offers a useful explainer on just how recombination occurs.
The constant stream of minutes from various government hearings and meetings are always worth tapping into – particularly SAGE, the Health and Social Care Select Committee and the Science and Technology Committee.
And for a quick rundown on how the UK is monitoring and studying new variants, this overview in the British Medical Journal is useful.
On herd immunity
The term “herd immunity”, coined almost a century ago, only became familiar to most of us last Spring when mentioned in a news briefing by Chris Whitty and Patrick Vallance. To understand exactly how herd immunity works from an epidemiological perspective, this in-depth guide in the medical journal Clinical Infectious Diseases is a good starting point.
As for how scientists calculate herd immunity, The Lancet has a useful explainer. As you might imagine, the maths gets quite complicated but the key components are vaccine efficacy and the R number. If it is assumed that immunity is short lived – say, 12 to 18 months – the calculations become even more complicated.
There are, of course, two types of herd immunity: natural herd immunity – i.e. allowing a virus to let rip – and the kind of herd immunity created through vaccinations. As the Washington Post’s Daniel Drezner points out, and, as was made clear in the UK from the outset of the pandemic, the former is a controversial strategy for governments to take.
Among many other critics of natural herd immunity is Christine Aschwanden, who remarks in Nature that we have “never successfully been able to do it before” and that it only leads to “unacceptable and unnecessary untold human death and suffering.” It’s also worth listening to The British Medical Journal’s brilliant podcast with Chris Whitty, who agrees with Aschwanden: “for the great majority of the infections I’ve dealt with… you never get herd immunity”.
Of course, nobody is safe until everybody is safe. Global access to vaccines, tests and treatments is the only way out. For a weekly update, Tim Hardford’s brilliant podcast How to Vaccinate the World on BBC Radio 4 is worth listening to.
Yet vaccine nationalism by high income countries is undermining Covax’s efforts to make vaccine access more equal. As reported in the New York Times, more than 130 countries still haven’t vaccinated a single person. The Wall Street Journal has a useful explainer on what Covax is trying to do.
For a whistlestop tour of vaccine development, the i newspaper offers a glimmer of hope – as does The Atlantic on how our very own antibodies can evolve. And Meredith Wadman’s book, The Vaccine Race: How Scientists Used Human Cells to Combat Killer Viruses (2017) is a gripping tale of how scientists work together to fight disease by immunisation.
Genomics is the science of gene sequencing, which is how we find out if variants are emerging. Sharon Peacock is a key figure in the UK for leading sequencing of SARS-CoV-2 and The Conversation ran a great Q&A with her back in February. As for how the UK became a world leader in the first place, Joanna Sugden’s piece ($) in The Wall Street Journal maps it out well.
But much of the analysis of genome sequences rests on the initiative of academic researchers. Alongside others, Emma Hodcroft suggests a whole host of recommendations in Nature which would help phylogenetics researchers learn even more from their analysis.
And finally, whilst it’s important to understand the science, Rachel Clarke’s Breathtaking: Inside the NHS in a time of pandemic (2021) is an important reminder not to lose track of the people. Her stunning and often heart-breaking account of life and death on the wards during the first wave is a reminder of what we must strive to prevent happening again – at all costs.