As of the end of September, the Delta wave was in decline throughout almost all of the United States.  The outbreaks in the South, including Texas, have dramatically declined.

Hospitalizations

US hospitalizations as of the end of the month had dropped to 72,000.  That is down from 94,000 at the height of the Delta peak in the first part of the month and just over half of the January peak.  The rate of decline is gradually accelerating, now at about -1,000 per day.  New hospitalizations are down by similar amounts.

Hospitalizations are declining in all of HHS’s ten regional reporting areas, except the Mountain Region.  The fall in hospitalizations in the South has been truly stunning.   This is the new hospitalizations chart for Region 4, which covers most of the southeast.

Hospitalizations in Texas turned down dramatically in the last week of the month.  As of September 30, hospitalizations were down to 8,663 from just under 14,000 in late August and are now falling about 300 per day.  Yesterday, hospitalizations feel below 8,000 for the first time since August 4. That is a 40% drop in a month.  ICU bed usage peaked a little bit later and now is also down, although not quite as dramatically (3,834→2,861 = -26%).

New COVID hospitalizations in Texas are down to under 1,000 per day from the peak of about 1,700 in late August.  The decreases were fairly uniform across the State.  There were only three regions, all in west Texas, that did not see a decline in September but those were already at pretty low levels.

Fatalities

The CDC fatalities data appears to have settled down as it is not showing the significant daily backdated revisions we had been seeing.  According to its latest tally, fatalities peaked around the middle of September at about 1,700 and have declined since then to about 1,500.

The Texas date of death analysis is still showing that fatalities peaked around the end of August but it looks like the peak is now going to be in the 320-330.

The rise in fatalities has begun to push up the numbers on the CDC Excess Death Analysis.  It is now showing that excess deaths topped out at about 30% above what would be normal for the last two weeks in August.  That is compared to the January peak when excess deaths reached over 40%.  However, excess deaths stayed at those levels for about six weeks in the January peak, while it appears this one will be significantly shorter.    

Vaccines

The rate of vaccinations continues to gradually slide with less than 600,000 doses now being administered daily.  The percentage of the US population fully vaccinated has crept up to 55.7% and to 83.4% of seniors. The percentages in Texas have moved up by about the same amount, now at 51.2% and 79.0%, respectively.

Testing Results

Nationwide, testing leveled out at about 1.6 million tests per day.  The CDC’s daily seven-day average of “new cases” continued to steadily  fall.  As of the end of September, it stood at 105,000, down from 160,000 at the Delta peak.  The current nationwide positivity rate dropped to 6.8%

Texas’ seven-day average for “new cases” has dropped by nearly half in the last two weeks, falling from about 15,000 to 9,000.  The positivity rate for the State’s date of specimen testing has also begun moving dramatically down in the last week.  It ended September at 9.8% after being stuck at around 15% for most of the month.

Conclusion

Following up on the analogy I suggested in my last report, it is becoming increasingly clear that the seesaw has tipped back in favor of herd immunity and that the Delta wave in the US will have largely subsided within the next few weeks.  The question on everyone’s mind is what comes next.

There are still those that argue that the epidemic will go on forever because (i) of breakthrough infections, (ii) immunity does not block transmission and (iii) more new variants will arise interminably, tipping the seesaw back.  I do not find any of these arguments persuasive.

I plan to write on breakthrough infections in the next week or so but suffice it to say for now, that they are roughly what we should have expected based on the vaccines’ trial results.  There is very little data on breakthroughs after a previous infection but since the vaccines basically induce the body to mount its natural defense mechanisms, the rate of breakthroughs for natural immunity is likely similar to that of vaccines.  The bottom line is that there are not enough breakthrough infections to support an epidemic level of the disease.

The consensus of the studies emerging on transmission after vaccination is increasing concluding that while the vaccines do not completely prevent transmission, they likely very significantly reduce it.  This may be because immunity works to reduce the viral load in a second exposure which appears to be a key factor in transmission.  Again, we have almost no data on transmission after natural immunity, but the best bet is that it is similar to vaccines.

Most of the angsty about transmission came from this contact tracing report the CDC published on  bizarre case in Provincetown, Massachusetts.  It was this report which caused the CDC to recommend people who had been vaccinated to wear masks indoors.  I was unimpressed by the methodology or that analysis of the report and no similar case study has emerged since then.  Personally, I think the CDC overreacted and in the process, gave anti-vaxxers ammunition for their argument that the vaccines do not work.

Finally, while it is certainly possible a new variant could emerge, it is hard to imagine one that is more contagious than Delta.  So, the concern would be that a variant evolves that escapes previously acquired immunity.  So far, while some of the variants appear somewhat less vulnerable to pre-existing immunity, none to the extent that they could fuel another epidemic phase.

Probably the most exciting development is that Merck has announced a new anti-viral pill that interferes with the virus’ ability to replicate.  In trials it reduced serious COVID by over 50%.  This could be a real game changer.  The developers of the drug also think it may have application in other viruses, including the flu.

I will not report to you again until the end of October unless there is some change in the trajectory of the decline of the Delta wave.  Based on the previous waves, we will hopefully be telling Delta, “Good-bye and good riddance.”