Covid-19: What you need to know today
The UK announced a surprise lockdown on Saturday in London and parts of the country. The decision was forced on the Boris Johnson government by a surge in coronavirus disease (Covid-19) cases. The UK is now seeing its third wave of infections — or, a second wave which appeared to be waning till it suddenly gathered momentum — with the country recording around 35,000 new infections on December 17, the highest in one day.
The UK’s sudden decision can be attributed to the discovery of a new strain of the Sars-CoV-2 virus, which causes the coronavirus disease, and which, Johnson said while imposing the lockdown, was 70% more infectious than other strains of the virus. It is believed that most of the new cases in the country are driven by this variant, with up to 60% of the cases in London being caused by it.
The London lockdown, which upends the Christmas and holiday plans of many of the city’s residents, was announced late Saturday afternoon, but came into effect only at midnight — resulting in a large-scale exodus from the city to the countryside, the kind of scramble avoided at any time, but especially when a viral pandemic is raging through the city and the country. Days before he announced the lockdown, Johnson said that it might be necessary to impose one after Christmas — but clearly, his hand was forced by fears of a mutant strain.
It isn’t just the UK; South Africa announced on Friday that a new strain of the Sars-CoV-2 virus has been detected in the country, and that this could be driving the second wave of infections in the country. The country has seen a spike in cases since mid-November, and the seven-day average of new cases is around 70% of the peak seen in the first wave, and rising.
There are some interesting similarities between the new strains in the UK and South Africa. Both, health authorities in the two countries claim, appear to be spreading faster. The two strains appear to share a mutation, one that alters the structure of the spike protein of the virus. Health officials in both countries believe this could actually be helping the virus spread faster — after all, the spike protein is how the virus binds to receptors in human cells. In South Africa, scientists studying the variant claim that the new strain results in higher viral loads in patients — based on studies of swab samples.
Here’s what we know: both new strains (the South African one would appear to be older and more widespread, based on what the country’s health authorities say) show a significant number of mutations, including a shared one (N501Y is what scientists are calling it) that affects the spike protein. And both strains appear to be more infective.
Viruses mutate, so the fact that Sars-CoV-2 is showing mutations is neither strange nor cause for alarm. But these mutations could have a bearing on its virulence as well as the effectiveness of vaccines and that is definitely something that merits further study.
Here’s what we do not know: we do not know for sure if the new strain is more infective; we do not know for sure if the new strain results in higher viral loads in patients (which, in turn, makes it more infective); we do not know for sure if the new strain causes more severe forms of Covid-19 (initial evidence would seem to suggest it doesn’t, but we do not know for sure) and results in more deaths; and we do not know if the vaccines that have so far proved successful against the virus are effective against the new strain as well.
That’s a lot of we-do-not-know-for-sures , but that is exactly the way science works. It will be interesting to see if the current strain(s) of Sars-CoV-2 being detected in India show any of the mutations seen in the new strain in the UK and South Africa, especially the N501Y one.