In a recent article published in the New York Times, the science writer Zeynep Tufekci argues that the B.1.617.2 “Indian” variant appears to be more transmissible than even the B.1.1.7 “Kent” variant, and could therefore be “catastrophic” for parts of the world with low rates of vaccination.
As a consequence, she argues, vaccine supplies should be “diverted now to where the crisis is the worst, if necessary away from the wealthy countries that have purchased most of the supply.”
While asking rich countries to share their vaccine supplies with poorer countries surely makes sense, one of the points Tufekci makes in support of her argument is based in error. Linking to Our World in Data’s chart of UK daily deaths, she writes:
Britain had more daily Covid-related deaths during the surge involving B.1.1.7 than in the first wave, when there was less understanding of how to treat the disease and far fewer therapeutics that later helped cut mortality rates. Even after the vaccination campaign began, B.1.1.7 kept spreading rapidly among the unvaccinated.
In other words, she’s saying that the higher mortality rate observed in Britain’s second wave, following the emergence of the “Kent” variant last November, constitutes evidence that new variants can pose serious and unforeseen challenges to national healthcare systems.
However, it simply isn’t true that there were more COVID-related deaths “during the surge involving B.1.1.7”. As I’ve noted before, the chart showing deaths within 28 days of a positive test (to which Tufekci links) gives a very misleading impression of the relative severity of the first and second waves.
The correct chart to use is the one the ONS published on 19 March, which plots age-adjusted excess mortality up to 12 February:
The peak weekly mortality in the first wave was 101% higher than the five-year average. Yet in the second wave, it was only 42% higher.
What’s more, cumulative excess mortality was 483% in the first wave, but only 328% in the second wave. Of course, the latter figure is an underestimate because the series stops in mid-February. However, extending the series forward wouldn’t make that much difference. Indeed, there were nine consecutive weeks of negative excess mortality in March, April and May.
Countries with low rates of vaccination should certainly remain vigilant with respect to new variants, but decisions need to be based on the best available data – and that means age-adjusted excess mortality wherever possible.