Covid-19: What you need to know today
The big news of Monday was the big news of Sunday, which was the big news of Saturday – the new strain of the coronavirus in the UK. Following the lead of many other countries, India too stopped flights from the UK till the end of the year, but it may be too late. According to a report in virological.org by researchers from several UK universities – the report was authored for the Covid-19 Genomics Consortium, UK, a public-private partnership that seeks to “collect, sequence and analyse the whole genomes of virus samples in the UK” – the first samples of the strain (now called B.1.1.7) was collected on September 20. That’s three months back, which probably means that most countries barring the entry of travellers from the UK, or stopping flights to and from that country are probably too late. There is a very high probability that the strain has already entered their countries.
Between the time I wrote Dispatch 229 on Sunday and the time I am writing this, scientists have figured out even more about this strain, and the bad news would appear to be that, at least in a laboratory setting, it is more infective than the older strain. It also emerges that the strain is now the dominant one, at least in the UK, but that should not come as a surprise to anyone – that’s how mutations often work. According to the report in virological.org, three of the new strain’s multiple mutations (17, according to most reports), are interesting. One, which I wrote about in yesterday’s dispatch, Mutation N501Y, effects a change in the spike protein of the virus, possibly making it bind better with human cells; another, also in the spike protein, could, researchers suspect, help the virus evade the host’s immune system; and the third, whose effects are not known, is close to the cleavage site of the spike protein. This is the site which reacts with the human enzyme furin, resulting in the spike protein breaking into two parts, with one part (S1), attaching itself to the ACE receptor found in human cells, facilitating the entry of the viral matter. It’s easy to see how all this could make the new strain more infective, but as I pointed out yesterday, we will not know for sure till more studies of infectivity happen, and more genomes of the virus are analysed – and both need to happen across the globe.
India may be seeing a lull in new cases, but this is no guarantee that the new strain isn’t here already. The country has had a so-called travel bubble with the UK since May, with 70 flights a week between the countries. This can be established through a large-scale genomic analysis. India has been analysing viral genomes from around the country, and while this does not seem to have been on the same scale as the UK’s, if there were a new strain of the virus rapidly emerging as the predominant one, it is likely to have been picked up.
The UK scare is likely to push India (and many other countries) to sequence more genomes of the virus. According to an article in Science (sciencemag.org), the UK’s efforts at identifying the new strain were helped by the fact that one of the commonly used RT-PCR tests in that country, TaqPath, showed pieces of only two genes in the result if the virus was the new strain (as compared to pieces of three genes for the older strain; one of the genes is hidden by one of the mutations). This kit is approved for use in India too (according to the website of the Indian Council of Medical Research), but this columnist doesn’t know how many labs, if any at all, use it. That would be a good starting point for India’s investigations into the new strain.