Michael norton:
– “So we are “finding” people who have some covid in them, even if they have been doubled jabbed, like our new Health Secretary. We test double any other country, if France tested as many as are tested in the U.K. they would “find” many more people with some covid in them.”
PCR indeed can be sensitive enough to detect fragments of virus from old infections that people’s immune system have killed, but if the high infection prevalence found were caused merely by the number of tests performed, the graph of positive test results would have a shape similar to the graph of total tests performed. It doesn’t. The graph of tests performed is here:
https://coronavirus.data.gov.uk/details/testing
No resemblance. The positive tests graph has the characteristic rising curve of anything that grows, including a spreading infection.
A proportion of samples that tested positive are also sent to Milton Keynes for genetic sequencing. Virus fragments from old infections are revealed because they’re too short to be sequenced. And when infection prevalence is rising fast, as it is now, new, active infections will always greatly outnumber detections of old virus fragments.
If testing were reduced we’d just degrade our data source for assessing how effective the various vaccines are, and our warning about potential oncoming hospital demand. Abandoning testing is a “rose tinted spectacles” strategy, or “head in the sand” to be less polite about it.