The UK released an update on the delta variant today.
One interesting tidbit was that household secondary attack rate of the delta variant is in decline. This means that people are not spreading this variant as much to people that they live with. That might reflect more vaccinations, or simply people being more careful. Whatever the reason, it's a good thing.
The bad news is that they are seeing an increase in re-infections in the SIREN study. This study consists of thousands of health-care workers who have had a prior PCR-confirmed infection. When vaccines became available to them in Dec/Jan, most of them were vaccinated, and new PCR positives in this group went down to almost zero. Now the numbers of people who are testing positive again are going up.
The rate of deaths continues to be fairly low for delta, although they are seeing some increase now simply because of the increase in the number of cases.
By my rough calculations, vaccine efficacy against death from the delta variant is 91% for those over 50. This is based on an update of cases that onset by June 21.
