We’re publishing an original piece today by Mike Hearn, the former Google software engineer who is the author of this site’s most read piece. (He used to contribute under the name Sue Denim, but has since come out.) It’s a review of a recent paper in the Lancet purporting to show that 20% of Danes infected in Denmark’s first wave became reinfected in the second wave. As Mike reveals, this conclusion was based on assuming the false positive rate of the PCR test is much lower than the researchers had any reason to assume. Here are the first three paragraphs:
A recent paper in the Lancet claims that one in five people might not get immunity from being infected with COVID. The study is invalid. Although these sorts of problems have been seen before, this is a good opportunity to quickly recall why COVID science is in such dire straits.
The research has a straightforward goal: follow a population of Danish people who tested positive in Denmark’s first wave, and re-test them during the second wave to see if they became infected a second time. Denmark has a large free PCR testing programme so there is plenty of data to analyse. Out of 11,068 who tested positive in the first wave, 72 also tested positive during the second wave. This fact is used to advocate for vaccination of people who’ve already had COVID.
The obvious problem with this strategy is that false positives can cause apparent reinfection even when no such thing has happened. The paper doesn’t mention this possibility until page 7, where the entire topic is dismissed in a single sentence: “Some misclassifications by PCR tests might have occurred; however, the test used is believed to be highly accurate, with a sensitivity of 97·1% and specificity of 99·98%.” My curiosity was piqued by this figure because, as I’ve written about previously, at least as of June last year nobody knew what the false positive rate of COVID PCR testing is. The problem is circular logic: COVID is defined as having a positive test, therefore by definition it has no false positives, even though we know this cannot be true.
Worth reading in full.
Stop Press: The New York Times reports on a new study showing that eight months after infection most people who have recovered from coronavirus still have enough immune cells to fend off the virus and prevent illness. A slow rate of decline in the short term suggests that these cells may persist in the body for a very, very long time to come.
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Re Toby’s tweet
‘Mixed messages on lockdown enforcement have created a no win position’.
Should read
‘Using strong arm bully boy tactics to illegally assault members of the public on camera has created a no win position for police.’
It should not be difficult to identify this thug in uniform repeatedly kicking an MOP who is already down.
The ginger twat has red shoulder markings and is carrying a red crash hat which, I believe, marks him as a snatch squad goon leader.
Action this day bozo.
This one
“The New York Times reports on a new study showing that eight months after infection most people who have recovered from coronavirus still have enough immune cells to fend off the virus and prevent illness. A slow rate of decline in the short term suggests that these cells may persist in the body for a very, very long time to come.”
But we already suspected this given that people who recovered from the original (and very similar to SARS-COV-2) SARS 1 still had resistance to it 17 years later, probably as a result of memory T cells recognising it.
I’m not sure Mike Hearn is barking up the right tree here? The Danish paper reaches its conclusion by comparing apparent re-infection rates (true or false) between two cohorts who had tested positive (truly or falsely) in the 1st wave and tested negative in the 1st wave (again truly or falsely). They find that the infection rate is just over four times lower. If false positives played an overwhelming role, the two reinfection rates would be very similar, because a false positive doesn’t require the patient to have the virus, so it would be irrelevant whether they are immune or not. The actual false positive rate would tend to dampen the result, but it is unclear by how much. They also analyze a subset who were tested frequently (typically 10 times in all) and find a very similar ratio, in fact they find the protection is slightly better. The actual infection rates approximately double between frequently and infrequently tested groups, but that might be due in part to the fact that they are high exposure groups (healthcare, social care) who are more likely to become (re)infected in the first place. Rather than querying the result itself, a better sceptical response… Read more »
Thanks for the comment. I’m afraid I’m having a bit of trouble following your argument. People who tested negative in the first wave cannot have a reinfection rate. The key issues here are a bit higher level though: There were only a small number of apparent reinfection. With even a small FP rate, every single “reinfection” would be noise. Their explicit conclusion that the immune system cannot be relied upon and everyone must be vaccinated requires that reinfections exist, although we’re talking about a whole 72 people in a population the size of Denmark. They do not know what the actual FP rate is and use a figure that’s simply made up. For me point (3) is critical. The research standards just aren’t there. A number that is simply a made up scenario input to a model is passed off in the text as the state-of-the-art belief about real FP rates. What kind of scientist uses made up numbers when they affect their conclusions? How can anyone trust academic output when these practices are rife (which they are)? You’re arguing the FP rate(s) don’t matter for this analysis, but that surely isn’t the case. As a thought experiment, if the… Read more »
Re the New York Times article and immunity – I wonder if Doris has had this read to him by one of his minions?