The new variant of Sars-CoV-2 is, according to government experts, 71 per cent more transmissible than the previous dominant form, increasing the reproductive rate by between 0.39 and 0.93. But is it any more or less deadly than the older version? All Nervtag has revealed is that there have been 4 deaths recorded among 1,000 cases of the new variant. A rough estimate of the infection fatality rate based on those figures would not be out of line with estimates for the virus as a whole — although the advisory group adds there is not yet enough data to draw any conclusions.
If there were a dramatic difference between the death rate between the old and new strains, however, it would presumably start to show up in the regional data given that the variant strain is much more prevalent in London and the South East. Around 60 per cent of new cases in London are now the new variant. So does London have a higher or lower death rate than other parts of the country? One way to get a rough idea is to compare the number of deaths in each region with the ONS data on the prevalence of Covid-19 two weeks earlier — two weeks being the typical delay between a positive test and death, where that occurs.
This morning the ONS published its latest weekly figures for registered deaths. They show that in the week to 11 December there were 12,292 deaths in England and Wales — 14.3 per cent above the five year average for that week of the year (although that is unadjusted for the growing and ageing population). It was an insignificant 11 deaths fewer than the previous week. Reassuringly, the number of deaths where Covid was mentioned on the death certificate fell in London week on week: it was exactly 200 in the week to 11 December — that, too, was a drop of 11 on the week before. There were 294 deaths in the South East, up from 250 the week before.
Now to put these figures into context. Two weeks earlier, the week to 25 November, the ONS infection survey (which is put together from tests on a random sample of the population) estimated that around 56,700 were infected with the virus. So, for every 1,000 cases in London in the week to 25 November, there were approximately 3.5 deaths in the week to 11 December. The corresponding figure for the South East was 5.3. In the North West, where the new variant was a lot less common, the figure was 3.9. It was 3.5 for the North East, 4.3 for Yorkshire and the Humber, 3.5 for the North East, 6.2 for the West Midlands and 5.1 for the East Midlands.
These figures shouldn’t be treated too literally. The ONS figures for prevalence are only an estimate based on a sample of the population, albeit a fairly large one. There is a delay in the recording of deaths and not everyone dies two weeks after they have caught the virus — there is a wide variation. There may, too, be regional differences in the age profile of people catching Covid-19. But if there were a dramatic difference between mortality from the new strain of the virus and the previous strain you would expect it to show up in death rates between regions where the new strain is prevalent and those where it is not. So far, this doesn’t appear to be the case.
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