Okay, so just a couple of big-picture comments before a few more research summaries, that are related to these comments. Number one, notwithstanding Dr. Fauci’s apparent ignorance on the topic (I know he is busy, but it is pretty inexcusable to be so far behind on a very key piece to the puzzle), there is now a literal flood of research demonstrating that memory B cells and T cells from prior coronavirus infections do react against regions of the CV-19 genome. It is almost certain that this accounts for the vast majority of cases being asymptomatic or mild. This is extremely good news, which I do think is played down or ignored in part because it runs counter to the hysteria trend, and in part because it suggests a vaccine isn’t all that important, which big pharma definitely doesn’t like. We should take our time on the vaccine and get it right and as we do with flu, focus on a vaccine that is likely to prompt adaptive immunity against a wide variety of CV strains, as the study I posted on earlier today suggested.
Second, could it be more obvious that we have a testing problem, and the more we test the worse it gets. In a low prevalence environment, and that is what we have, false positives are inevitable and can comprise a significant part of all “positive” results. Second, the cycle number issue on PCR tests is real, and using false positives as cases diverts resources and feeds hysteria. Doctors need cycle number information for triage and treatment purposes. We should cut testing back to those who are symptomatic and those who are known to have been in contact with a symptomatic person.
This first study relates to one of my other pet peeves, getting children back to normal school. (ES Study) Coming from Germany, it tracked case development after schools were opened. “Outbreaks” in schools accounted for one-half of one-percent of all cases, and only 3 tenths of a percent of cases. And since they included college students, half the cases were actually in “children” over the age of 21. You get the picture, younger school age children represented almost no cases. Most cases were asymptomatic.
This paper looked at viral loads in nursing home residents and staff with and without symptoms. (Medrxiv Paper) 15.5% of residents and 4% of staff tested positive. 70% of residents and 90% of staff who were positive had no symptoms at the time of testing. Cycle numbers were similar for symptomatic and asymptomatic positives early in the epidemic but diverged later. The range, about 11.5 to 37, similar for the groups, as was the average, around 28 to 29 cycles. The range implies a variation in viral load of 250 million times. Yes, you saw that correctly. So most of the viral load is in people with low cycle numbers. 24% of tested people, with cycle numbers of 21 or under, had 99% of the total viral load. Some of the aysmptomatics may have been presymptomatic, the study did not determine this. So this research suggests similar viral loads in asymptomatic (some may be presymptomatic) and symptomatic persons at the time of test, but also suggests that when you get above even cycle number 25 you are dealing with very small virus loads.
And here is a commentary in Lancet discussing the issues with false positives from PCR tests. (Lancet Article) Among issues touched upon is the likelihood that test performance is not the same in the real world as when the test is validated in the lab, the effect of a testing strategy which expands to a low prevalence population, and mis-direction of resources and policies. Even if false positives are less than 4% according to test validation, in a low prevalence environment a far higher percent of positive results would be erroneous.
And this is the third study in a couple of days identifying cross-reactive immune responses. (Medrxiv Paper) T cell responses were studied in 168 CV-19 patients and 118 non-infected persons. The authors were not only attempting to assess the presence of a cross-reactive response but were testing the ability of various T cell assays to identify the cross-reactivity. A very important finding is that they got very different results depending on the assay used. As others have, they found a strong, multiplex T cell response to infection, but also variable in regions of the CV-19 genome reacted to. Some assays detected little response, while more sensitive ones picked up a significant T cell response. And among those persons who had not been infected, while one common assay detected no cross-reactivity, the more sensitive one again picked up significant response, 85% for helper T cells and 50% for killer ones. And this response was directed at the spike protein, which contains the receptor binding domain used to gain access to human cells. Aside from validating the existence of cross-reactive responses, the study shows the importance of using multiple assays to detect and track immune responses.