The US is now over 30% Delta variant for new cases. So how could the 7-day average still be heading down, now at 3.2/100,000? Here compared w/UK trajectory, >93% Delta 
There's no question that of the new cases in the US, many are Delta, but sequencing is minimal. The 30%+ is based on a limited sample (wide 95% CI) compared with the UK. Look at the numbers at bottom of US, UK graphs outbreak.info
The 30% Delta is very unevenly distributed. Missouri is >60% and is the hotspot of the US for new cases. Neighboring states Arkansas and Oklahoma are also heating up and have high Delta frequency.
It's still early to assess the Delta hit. With doubling every ~11 days, the next few weeks will be telling. Our genomic surveillance is still weak. If vaccinations could be substantially increased beyond our current 54% population, we'd be in great shape to reduce its impact.
• • •
Missing some Tweet in this thread? You can try to
force a refresh
