Off we go with another scintillating review of new research on the exciting field of CV-19. Ooops, a little excessive enthusiasm there, too much Dr. Pepper early in the morning (actually I got detoured with real work most of the day so just finally finishing this up tonight).
My guess (if it comes true I am going to call it a prediction) of peak or plateau being in the Nov. 9 and Nov. 16 weeks is starting to look kind of good. Thanksgiving will hose up the analysis, but that timing appears possible now. If that is the case, it has absolutely nothing, zero to do with anything the Governor did, it will have happened before anything he did could have taken effect. With every day it becomes clearer that the Dakotas and Wisconsin have peaked/plateaued and today the Mayo Clinic said positivity rates were down in its service areas. Just remember the Governor said it takes four weeks for the effect of his orders to be seen.
I am tired of reading these stories and reporting them. I am calling for a national commission to prosecute politicians, the teachers’ unions and school boards for crimes against children. Someone has to pay for the inexcusable and immense damage being done. Even the whacko Washington Post has noticed. In Fairfax County, Virginia, (WP Story) As a result of online learning the percentage of F grades rose over 80% and this in schools that have incredibly low standards and expectations. And guess what group of students was most impacted? Minorities and low-income ones. But, oh yes, we really care about our children and about equality.
This article estimates total antibody prevalence in the US as of September, based on tests done at two large clinical lab companies over the course of the epidemic. (JAMA Article) The people doing the surveys aren’t keeping up with the research. Circulating antibodies don’t matter much, memory B cells and memory T cells seem most important and those seem present in almost every infected person and seem to last for as long as a patient can be studied. In addition, there continue to be questions about the adequacy of some assays to detect antibodies accurately. In any event, these researchers summarize prevalence at around 1% to 23% (New York), depending on location. Some odd results occurred, including a supposed decrease in prevalence in North Dakota during the entire two month testing period. Minnesota was singled out for its increase in prevalence and as of late September was at a mid-range of over 10% with a high end of around 15%. At 10%, that is 570,000 cases or 6 times the reported number of cases as of September 24, the end of the study. Given case growth since then, if the same ratio applied, we are at well over 1.5 million cases, which would greatly slow transmission. Very interesting stuff.
I have mentioned before hypotheses that certain vaccines, including the tuberculosis one, may protect against infection or severe disease. This paper again looks at the BCG, or tuberculosis vaccine and finds a basis for a protective effect by comparing certain peptide sequences in the vaccine against CV-19 peptide segments. (Medrxiv Paper) Trials are apparently under way to test the effect of BCG vaccines on CV-19.
Another paper on the issues with PCR tests and CT number cutoffs. (Medrxiv Paper) The paper notes that PCR thresholds that are commonly used are too high and recommends that each lab should do a correlation study to find the threshold that relates to culturing viable virus. For labs that can’t do this, they recommend a statistical analysis, which would suggest positives above 32 cycles are not identifying infectious cases.
A couple of antibody related studies. In the first, persistency was studied in patients for up to eight months following acute infection. (Medrxiv Paper) Three-quarters of the patients had a strong response of one type of antibody for the entire period, with those with severe illness more likely to show this effect. The second paper focused on the difference in antibody response, if any, from persons with mild, severe and critical illness in Japan. (Medrxiv Paper) The researchers found that those with severe and critical illness had a different course of antibody development than did those with mild illness. Their interpretation of this was that the mild cases actually had pre-existing cross-reactive antibodies which limited the infection and the need for development of additional antibodies.
These authors were attempting to identify the first index case in Hubei province, where the epidemic appears to have originated. (Medrxiv Paper) They estimated that this occurred in October or November of 2019. Most interesting is the speculation that there were likely multiple attempts by closely related strains to jump to humans, and the early ones failed to start an epidemic, but eventually a slightly different bug that was more infectious was successful.