How much should you worry about the “Indian variant”?

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RANDOM ERRORS occur every time a virus copies itself, blips on the lettering of its genome, like those a child might make while copying a passage from a book. Most of the errors, known as mutations, make little difference to the virus’s impact on any people it infects. But some do. A variant of SARS-CoV-2 known as B.1.617 is widely suspected to have played a big part in the disastrous spread of covid-19 across India in recent months. Millions have caught it and other variants. Hundreds of thousands are dead. The “617” variant has now spread to 44 countries. To understand how worrying it is, it helps to look to Britain, whose viral-surveillance system is the best in the world, making it a useful observatory through which the rest of the world can understand the variant.

The COVID-19 Genomics UK Consortium first detected it in Britain in February, but cases stayed low for months. Now they are rising. Weekly infections of B.1.617.2, a further-mutated form, have more than doubled in the last seven days, from from 520 to 1,313. On May 6th the government upgraded 617.2 to a “variant of concern”, the highest level of official alarm. On May 11th the World Health Organisation followed suit. How much should the world worry about the variant that has devastated India?

One can get some sense of the threat by attempting to answer three questions: how dangerous is it? How transmissible? And, most importantly, are vaccines effective against it? Start with the danger. The answer when it comes to 617.2 (and all of the variants) is that no one really knows. The question of whether SARS-CoV-2 is becoming more or less dangerous as it evolves is a matter of some debate in the scientific community. It is unlikely to be settled for some time. Mapping the severity of illness caused by each variant is hard. There has, naturally, tended to be little thought given to sequencing the genomes of the viruses infecting covid-19 patients who cannot breathe. Hospitals in Britain are now starting to do this in an attempt to understand the threat that different variants pose. In the face of uncertainty, assuming that the new variant is at least as dangerous as the others is sensible.

Transmissibility is clearer. Geneticists and epidemiologists can keep track of which variants pop up in which places, thereby getting some sense of how easily each is spreading. All the variants are more transmissible than the original virus that spread around the world in early 2020. There is no strong evidence presently available that 617.2 is more transmissible than other variants, although it is one plausible explanation for why 617.2 is starting to outcompete the older Kent variant (B.1.1.7, see chart). For now, the Kent variant still dominates.

Transmissibility intersects with vaccination. The majority of cases in 617.2 hotspots like Bolton and Blackburn, in the north-west of England, are in younger people, most of whom have not yet been vaccinated, while cases in people over the age of 60, the vast majority of whom are fully vaccinated, are flat. This is encouraging. So is a small study, not yet peer reviewed, carried out by the Indian Council of Medical Research, which shows that India’s Covaxin does stop 617. But a similar study in Germany found that the variant bypasses antibodies induced by the shot developed by Pfizer and BioNTech to some extent. These are lab bench tests, but some real-world data are starting to emerge. When 15 people in a care-home in London—in which all the residents had received their second AstraZeneca jab—got infected with 617.2, four of them went to hospital and none of them died. At a care home in Delhi, in India, 33 fully vaccinated staff got infected with 617.2. None became seriously ill. If 617.2 was escaping vaccination in a way that posed a threat, those numbers would probably be higher. At the end of the week ending May 8th, the number of people with covid-19 in England was still falling overall, according to data released on May 14th by the Office for National Statistics.

Still, the British government is right to be wary about the new variant’s spread. A growing outbreak would force a reconsideration of its plans to further open the country on May 17th, when drinking inside pubs will become legal, and June 21st, when all legal restrictions on social activity are due to be lifted. Pausing or reversing the opening would be politically challenging. The rest of the world should pay close attention too. At present the body of evidence argues for vigilance, not panic. The figure to watch is hospitalisations with covid-19, currently at about 120 a day in England. If those remain flat or decline, that means 617.2 is not defeating vaccines. A sharp rise would be reminiscent of the spread of the Kent variant in November. That raced around the world, pushing many places into lockdown to avoid illness and death. If 617.2 can perform the same feat in a world that is at least partially vaccinated, that will be bad news not just for Britain, but for the world.

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