Below I link to a report with the UK’s up to date Covid information which provides:
- cumulative case counts for each variant
- mortality rates for each of 2 age groups by variant,
- hospitalization rates for those presenting to the ER with each variant,
- and other information including vaccinations
“SARS-CoV-2 variants of concern and
variants under investigation in
Technical briefing 22, 3 September 2021″
You can see that mortality due to delta in the older age group (over 50 years) is about half that of alpha and beta-caused mortality, and mortality in the under 50 group is less than half what it for alpha and beta.
On pages 15-20 (Table 4) we see the following. I feel obliged to use the odd inclusion and exclusion data ((I) for inclusion and (E) for exclusion) used by the authors, as described below:
% admitted from ER (E) (I) Mortality rate, overall
alpha < 50 years 1.0% 1.4% 0.1%
alpha > 50 5.3% 8.6% 4.8%
beta < 50 1.0% 1.5% 0.2%
beta. > 50 4.2% 9.0% 4.2%
delta < 50 0.7% 1.2% 0.0%
delta > 50 2.8% 6.2% 2.3%
Below are the odd inclusion and exclusion criteria used in the report. But it really doesn’t matter which you use, for delta is milder using either, both in terms of deaths and in terms of percent hospitalized from the ER.
# Inclusion: Including cases with the same specimen and attendance dates
‡ Exclusion: Excluding cases with the same specimen and attendance dates. Cases where specimen date is the same as date of emergency care visit are excluded
to help remove cases picked up via routine testing in healthcare settings whose primary cause of attendance is not COVID-19. This underestimates the number of
individuals in hospital with COVID-19 but only includes those who tested positive prior to the day of their emergency care visit. Some of the cases detected on the
day of admission may have attended for a diagnosis unrelated to COVID-19.
^ Total deaths in any setting (regardless of hospitalisation status) within 28 days of positive specimen date.
On page 11 the report claims that the risk of hospitalization is greater for delta (which is shown to be false from the data in table 4) but the report cites other data (which it fails to include) to support its questionable point:
“The crude analysis indicates that the proportion of Delta cases who present to emergency care is greater than that of Alpha, but a more detailed analysis of 43,338 COVID-19 cases indicates that the risk of hospitalisation among Delta cases is 2.26 times greater compared to Alpha (Twohig and others, 2021 ).”
While the proportion of Covid patients who present to the ER with delta appears be greater, this could be a function of all the fearmongering about the delta strain.
The data presented, OTOH, are reassuring about delta mortality and hospitalization rates. The data are incredibly reassuring about young people: those under 50. Only 0.03% have died (my calculation, 3/10,000 cases) which is counted as 0% in Table 4 becauses the Tble includes one less decimal place. A considerably lower proportion of deaths per case (Case Fatality Rate or CFR) exists for delta compared to alpha or beta.
I have omitted the other variants here because there were less than 500 total cases identified for each in the Table.