delta rising

It is fairly obvious now that the delta variant (formerly known as B.1.617.2, first identified in India) is out of control in the UK, as the week-on-week increase in case numbers has been accelerating dramatically over the last 10 days.

Week-on-week rise in new cases, last 12 days, according to the govt. data site:
24.5. + 17.0 %
25.5. + 18.0 %
26.5. + 18.0 %
27.5. + 20.5 %
28.5. + 24.0 %
29.5. + 23.3 %
30.5. + 26.8 %
31.5. + 28.8 %
1.6. + 31.9 %
2.6. + 34.7 %
3.6. + 38.9 %

To unpack those data: any positive percentage means new cases in the last seven days are higher than they were in the previous seven days. A constant percentage means an exponential rise, but at around 20% per week, it would only double in four weeks or so, so if the figure stayed at 20% it would be nothing to panic about.

What really worries me is that the percentages are increasing, and even this increase seems to be getting faster. From Tue to Wed it was 4.2 percentage points more, a jump of a size we haven't seen recently. The likely explanation is that it started in a few clusters, but as these clusters haven't been containe, it's gaining more and more territory to spread in. If this trend holds up we will end up with a doubling time well under a week before the month is out, and then we're in trouble. Even if many of the most vulnerable people are vaccinated, the extra risks that they are likely to take because they feel safe after being vaccinated may well compensate part of the gain. The other part may be wiped out by the Delta variant being more agressive than the original version. Early data suggests it may well be, see today's report in the Guardian.

Hospital admissions are also on the way up, while deaths have just begun to rise again after Monday's minimum of 43 deaths in the last 7 days. Today this fitgure is 54. As cases have been rising for more than two weeks now, I am guessing that this was the turning point and deaths are also creeping up again.

I really don't think the lifting of all regulations can go ahead on June 21 as scheduled, and if it does we're bound to have a rather murderous summer which could rival the previous waves not just in cases but even in hospitalisations and deaths. There are always people unprotected, and an epidemic running out of control will eventually find them.

The other big covid news in the UK is that Portugal has been removed from the green list, which means people returning from there are not exempt from quarantine. This is of course a distraction. As we have a Variant of Concern spreading out of control in the UK, nobody should have been allowed to travel to Portugal in the first place, especially not those footballers who could have just sas well played their game in Wembley.

Update 6.6.: the last three days have continued the trend shown above. If anything, the percentages are rising faster ...
4.6. + 39.8 %
5.6. + 46.2 %
6.6. + 49.0 %

Meanwhile, clusters of Delta are also beginning to pop up in France ...