So much to get to all of a sudden and I am having trouble keeping up.
When the emergency ended in Minnesota, Scott Johnson at Powerline lost his access to submit questions. But there were questions piled up and Scott has received answers to all those. A couple of nuggets in there. The state gave us its process for deciding if someone died of CV-19. Among other things, if the death was more than 30 days after a positive test, they ask someone to see if it really was a CV-19 death. And if CV-19 isn’t listed but the negative test was less than 7 days before death, they ask for it to be rechecked too. I still don’t have a good picture of the interaction between the CDC and DOH. And given that they are clearly still cleaning up deaths from February and March and seem to be adding quite a few, I suspect we will have lots of deaths continuing to be added. Slowly but surely we are catching up to Sweden. We got the first breakout I have seen of outcomes by variant, but numbers are small so hard to read much into it. Based on those very small numbers Delta looks like it has a somewhat higher hospitalization rate than Alpha and the same death rate, but only 2 deaths from Delta. We also got more detail on breakthrough infections. The median age of hospitalizations was 74, as you might expect, it is the frail elderly getting hospitalized with breakthroughs. But again, DOH notes that many of these hospitalizations were not for CV treatment. The median age of death was 79. And once more we learn that many of the deaths among those hospitalized were not people admitted for CV. No person died of a breakthrough infection under the age of 45. And we got a really elaborate explanation for why we aren’t given cycle numbers from PCR tests, much of which made no sense, and which ignored all the research correlating cycle number with viral load and with likelihood of culturing viable virus.
A few more notes on the latest technical brief on the variants from the UK. I posted on this last week, but read through in more detail to see what little gems might be picked up. The UK is basically all Delta now. Between these technical briefs and other reports from the UK, like the regular survey to determine who has been infected, you can start to get some sense of how different Delta actually is from the other strains. The most interesting chart is on page 35 of that report. It shows cycle numbers from PCR tests across the Alpha and Delta cases among the vaxed and unvaxed populations, over time. Remember a lower cycle number indicates a higher viral load. What you observe is a changing average cycle number over time. How can that be? There might be several explanations, but one is that as a strain goes into a population, it differentially infects the most susceptible first, and these people tend to have more serious infections, higher viral loads and to be more infectious. As a wave proceeds, or a strain becomes more dominant, it infects less susceptible people who have lower viral loads. If you only see the front end, you think the strain is much more transmissible, but as time proceeds, you get a fuller picture and you see that on average, it has similar transmission characteristics. You would really need to stratify the population by susceptibility and compare viral loads in that fashion. And this hypothesis is borne out by the household and other contact tracing, which shows only modestly greater transmission by Delta. A similar effect of changing average cycle numbers is seen in the prevalence surveys in the UK. It should be noted that vaccination has likely also skewed detection of cases towards only those with higher viral loads, as many vaccinated infections are likely quite brief and symptomless. And the prevalence of the virus in the community also appears associated with average cycle numbers.
Remember that I have been saying for a long time that hospitalizations have to be viewed skeptically both because a lot aren’t for CV-19 treatment, but also because remdesivir requires inpatient administration and at least some of the patients who get it wouldn’t otherwise have to be hospitalized. This study details changes in hospital treatment of CV-19. (Annals Article) Among these patients, remdesivir use went from 1.7% in March to 53.8% in December 2020. Use of the ICU declined substantially, largely because use of mechanical ventilation also decreased dramatically. If you think doctors always know what they are doing, this is a great example of how what they swore they had to do, put everyone on ventilators, was really bad for patients, and now they try to avoid it.
This is an interesting article on some of the issues with the mRNA vaccines. The designers likely made some non-optimal choices, but as the author points out, those can be fixed. The bigger issue appears to be that they did not mimic the results of actual infection very well in terms of a wider targeting of viral segments to prompt a response to. (AT Article)
And here is a good post describing the situation in Japan, which is having a bump in cases, but not much serious illness. (Japan Post)
Here from our very own Mayo Clinic in Minnesota is research on vaccine effectiveness in that large health system. (Medrxiv Paper) The study covered both mRNA vaccines from January to July 2021. Matched cohorts of vaccinated and unvaccinated persons were created. Prior PCR testing was used to try to weed out previously infected persons, but that isn’t going to do it without antibody testing, so there is some possibility that the unvaxed group includes people with immunity. The Moderna vaccine appeared more effective. It had an 86% effectiveness against cases and 91.6% against death. Pfizer had a 76% effectiveness against cases and 85% against hospitalization. There were no deaths, so basically 100% effectiveness there. Going by month, in July effectiveness stayed high against hospitalizations but declined in regard to infections. Moderna is likely better because it uses a much higher dose.
More information on the effectiveness of vaccines among LTC residents and staff. (Medrxiv Paper) All staff and residents listed in the country’s registry were included initially and those with verified prior infection were then excluded. The median age was 87 for residents and 39 for workers. Even in this group of very old residents, vaccine effectiveness was estimated at 81.5% for infection and 93% for death. Interestingly the vaccines had similar effectiveness among the health care workers at the facilities.
And another study along the same lines from Ontario, Canada, looking at the antibody response among LTC residents and staff following vaccination. Once again Moderna appeared to prompt a stronger response. After two doses, most residents had an antibody response similar to that from infection. Residents, however, with an average age of 88, had a much lower antibody response than did staff, average age 47. And there was less of a neutralizing response in both groups in regard to the Beta variant.
This study from Utah examines vaccine effectiveness against variants. (Medrxiv Paper) By the end of June, Delta was the vast majority of cases in the state. The researchers estimated vaccine effectiveness would be 82%, a decline from the effectiveness against prior strains, but still relatively good effectiveness.
Antibody response curves following either infection were studied in this paper. (Medrxiv Paper) The strength of the response was associated with the severity of infection. All participants retained a response up to the 12 month maximum followup period.
Most suppression tactics have no actual, real, non-modeling research evidence. This paper debunks the idea that early closing of bars and restaurants made any difference in transmission in Japan. (Medrxiv Paper)