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Getting the Story Straight on PCR…

A lawyer hyperventilating about PCR needs to be corrected…

Hyperventilating…

Here is an interview with a lawyer named Reiner Fuellmich showing what a full-blown hyperventilating fact-free attack looks like (please note: despite the introduction, the main body of the interview is all in English)

Going through his arguments is like shoveling the Augean Stables. But I’m no Hercules so I’ll focus on a very small but critical part of his argument, where Fuellmich tries to cast doubt on the polymerase chain reaction or PCR test. This is key because PCR is used to diagnose and track the COVID-19 disease and the SARS-CoV-2 virus that causes it.

What is Fuellmich saying?

Thanks to Robert Turner, we have a transcript of Fuellmich’s statements from that interview complaining about the PCR test:

[4:15] It [the PCR test] cannot be relied upon as it cannot distinguish between live and dead matter, meaning whatever tests positive to could very well be the fragments or remnants of your body’s own immune system’s fight against the common flu or the cold and it cannot tell whether a virus, and you need a whole virus, not just a fragment, whether a virus has entered your cells and is replicating because that’s the only way for you to become contagious.

[5:38]…you have to put this into a machine and then magnify it. This is called cycles of amplification, 2, 4, 8, 16, 32 and everyone agrees in the meantime that anything beyond 24 is unscientific. Apart from the fact, these tests cannot tell you anything about infection because they can’t distinguish between live and dead matter, but, if, if you go beyond 24 cycles, if you go for example to 34 cycles of application then you end up with at least 97% false positives, that’s what Mike Yeadon, former vice president of Pfizer told us.

Here I’ll focus on quickly laying down the facts to correct Fuellmich’s claims, and show where he is misleading people.

If you are interested in more in-depth primers on PCR, I have a couple posts here and here that I wrote for a friend who joined me in the lab doing biological research (including lots of PCRs).

Let’s break down Fuellmich’s comments piece by piece.

…It [the PCR test] cannot be relied upon as it cannot distinguish between live and dead matter…

Fuellmich tries to dismiss a test while displaying ignorance of what it does. First, a PCR test does not distinguish between living and dead. Second, being alive or dead has nothing to do with diagnosing COVID-19.

A PCR, or polymerase chain reaction, detects the presence of a defined genetic sequence by specifically amplifying it. That is the entire purpose of a PCR.

That genetic sequence can be encoded in DNA or RNA. In humans, our genetic information is permanently encoded in DNA, and transiently encoded in RNA. In some viruses like the one causing COVID-19, the genetic information is permanently encoded in RNA.

To detect RNA, such as that within the SARS-CoV-2 virus, an additional step transforms the RNA to DNA. This step is abbreviated RT (for reverse transcription). So, the test to detect COVID-19 is actually called an RT-PCR test.

The goal of PCR is to amplify, and therefore detect, specific genetic information encoded in either DNA or RNA.

PCR can, for example, detect the presence of a genetic sequence in tissue from a live person and one who has been dead for hundreds or even thousands of years. So, living and dead are irrelevant to the argument of PCR’s effectiveness.

Furthermore, being alive or dead has nothing to do with diagnosing COVID-19. The SARS-CoV-2 virus that causes COVID-19 does not even qualify as a living organism in many people’s opinions.

…whatever tests positive to could very well be the fragments or remnants of your body’s own immune system’s fight against the common flu or the cold…

Fuellmich displays complete ignorance of testing and biology in this statement. The RT-PCR test amplifies virus-specific genetic information. The RT-PCR test does not have anything to do with the patient’s immune system. The RT-PCR test does not detect anything specific to the patient at all.

Furthermore, testing has shown the RT-PCR test is so specific that it can distinguish the SARS-CoV-2 virus from other viruses including other coronaviruses.

The “common flu” is caused by several influenza viruses which are very different from the SARS-CoV-2 virus. Genetically and biologically, influenza and coronaviruses are very distinct classes and species. There is no possibility for the RT-PCR test to confuse the two.

The cold is caused by several human viruses including rhinovirus, several coronaviruses, influenza viruses, and others. Some of these belong to at least the same class of virus as the SARS-CoV-2 virus. However, the cold and COVID-19 viruses are all very different species. The RT-PCR test will not confuse any of them with SARS-CoV-2.

There are a couple recent coronaviruses which are much closer genetically to SARS-CoV-2, but testing has shown that the RT-PCR tests are able to distinguish between them. The one most closely related to the current pandemic virus is SARS-CoV, and one a little more distantly related is called MERS-CoV.

…it [PCR] cannot tell whether a virus, and you need a whole virus, not just a fragment, whether a virus has entered your cells and is replicating because that’s the only way for you to become contagious…

This statement is partially true, but is irrelevant to the logic and process of diagnosis, and irrelevant to the logic and process of public health.

The part of Fuellmich’s statement which is true is that the RT-PCR cannot distinguish between an intact virus, and free-floating viral RNA (perhaps what he calls “fragments”).

A clinical diagnosis of COVID-19 includes RT-PCR data as an important factor, but also uses clinical (symptoms) and exposure (who contacted whom) information as well. A clinical diagnosis requires multiple sources of information to increase confidence because treatments carry risks.

Public health does not try to make clinical diagnoses, but requires just enough data to suggest the spread of a virus. A positive RT-PCR result, whether the virus is intact or not, suggests that a transmission event (spreading from one person to another) has occurred. This spreading must be stopped quickly, and health officials must limit contact even before they have full clinical data.

…you have to put this into a machine and then magnify it. This is called cycles of amplification, 2, 4, 8, 16, 32 and everyone agrees in the meantime that anything beyond 24 is unscientific…

Again, a small part of this statement is true. During the RT-PCR test for COVID-19, the patient sample is put into what we call a thermal cycler, a machine which automatically heats and cools the sample according to a program in order to amplify (or make many copies of) a specific DNA sequence.

The detectability of the genetic sequence depends on how much DNA is there to begin with. If there is a lot of genetic material in the original sample, fewer cycles are required to detect its presence. If very small amounts of genetic material are present in the sample, more cycles are required. There is nothing about the magic number of 24 as being “unscientific”. The mere statement itself is unscientific, as it betrays a complete lack of understanding of the RT-PCR test.

RT-PCR tests routinely go into 40 or 50 cycles to amplify very small amounts of genetic material. Here is a graph of a typical RT-PCR to detect the SARS-CoV-2 virus, showing specifically that higher cycle numbers detect smaller amounts of RNA.

Example for amplification curves of the SARS-CoV-2 RNA at 100,000 copies/mL (1), 10,000 copies/ml (2), 1,000 copies/ml (3) and 100 copies/ml (4). Light blue curves: signals of the internal control (5) (Pfefferle et al, 2020)

… if you go for example to 34 cycles of application then you end up with at least 97% false positives, that’s what Mike Yeadon, former vice president of Pfizer told us…

Again, there is a tiny kernel of truth in this statement, but which is highly distorted. In the RT-PCR test, the genetic sequence is detected when DNA is amplified enough for a fluorescent signal to be detected. The number of cycles required to obtain a detectable signal is called the Ct, or cycle threshold number. A very high Ct number is associated with false positives. However, the number Fuellmich gives, 24 and 34, are ludicrously low and incorrect.

Here is one of many papers which explains the Ct value, and some typical values of cutoffs for acceptable values:https://drive.google.com/viewerng/viewer?url=https%3A//www.publichealthontario.ca/-/media/documents/ncov/main/2020/09/cycle-threshold-values-sars-cov2-pcr.pdf%3Fla%3Den&embedded=true

This paper suggests a Ct cutoff of 40. Far higher than 24 cycles or 34 cycles Fuellmich cites as being “unscientific”.

There are many causes of false positive RT-PCR results, of which the RT-PCR’s Ct is only one:

Causes of False Positive SARS-CoV-2 RT-PCR Results

Contamination during

  • Sampling (eg, an infected worker or surfaces; aerosolization of virus during collection)
  • Extraction (eg, aerosolization in containment hood)
  • PCR amplification
  • Production of Lab Reagents (eg, manufacturers of the positive control may have contaminated other reagents produced in the same facility; contamination of other consumables)
  • Contamination of the equipment by high viral titer specimens (eg, sample carryover)
  • Cross-reaction with other viruses (eg, other coronaviruses)
  • Sample mix-ups
  • Software problems
  • Data entry or transmission errors
  • Miscommunicating results
  • Variations in parameters around the LOD and definition of an indeterminate result
  • Assuming that an indeterminate result is a positive
  • Non-specific reactions

LOD, limit of detection; RT-PCR, reverse transcriptase-polymerase chain reaction.

(Table by Braunstein et al, 2021)

Conclusion

Fuellmich is engaging in a poorly-informed and dangerous campaign against public health measures such as vaccination, testing, and distancing. Even a cursory examination of RT-PCR shows how ignorant Fuellmich is of the process and capabilities of this important test.

Editors Note: For a complete dissection of Fuellmich’s Fiction, refer to this article

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Science Duuude
Science Duuudehttps://scienceduuude.medium.com/
Husband, dad, scientist, loves to share sciency stuff and goofiness. Follow me on Twitter

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