“Viral” load is a common measure that one often hears about from the CDC/WHO/MSM when discussing “Covid-19” and disease severity. It is considered an estimation of the amount of “virus” that is within a person’s body fluid. This is primarily determined through calculations based off the Cycle Threshold (Ct) Value from a PCR test. Virologists assume that if a person has a low Ct value, they have a high “viral” load and vice versa. They also assume that a low Ct value/high “viral” load equates to more severe disease. However, looking through various sources shows that correlation does not equal causation no matter how hard virologists may want that to be the case:
This first article states that various studies have found no difference in the “viral” load between those who have symptoms of “Covid-19” and those who are considered asymptomatic. They also note that there is no difference in “viral” loads between kids and adults, with kids being primarily asymptomatic. This clearly shows that a person’s supposed “viral” load (i.e. amount of “virus” estimated to be in the body) has no relation to disease severity whatsoever:
“Scientists have cleared up many mysteries surrounding the coronavirus, but one question still inspires debate: Does a person’s viral load, the amount of the virus in their body, determine how sick they get?
Common sense suggests the answer should be yes, higher viral loads produce a more severe outcome. But the coronavirus hasn’t always neatly followed that rule.
Studies have found little difference between the viral loads of patients who show symptoms and those who don’t. Scientists also haven’t found much difference in the viral loads of adults versus children, even though infected kids are more likely to be asymptomatic.”
“To measure viral loads, they relied on cycle threshold values: a measure of how much virus is detected within a sample from a standard PCR test. Patients with lower viral loads tend to have a higher threshold, since it takes more cycles to amplify the virus’ genetic material in order to detect it.”
“But the researchers offered a few caveats to these findings. When comparing outcomes, they didn’t examine confounding factors such as age or preexisting conditions, so more studies are needed. Cycle threshold values can also vary widely depending on how a sample is collected and how quickly it gets analyzed.“
However, one source is surely not good enough to make any definitive conclusions regarding the validity of a “viral” load. Let’s see what else we can find.
A study from January 2021 found no correlation between “viral” load and disease severity. In fact, mild cases had lower Ct values (suggesting higher “viral” loads) than those with severe disease. The use of “viral” loads as an estimate for disease severity was questioned as there were numerous factors that influenced the outcome of the Ct results, even with varying Ct results using the same sample and kit:
No correlation between Ct values and severity of disease or mortality in patients with COVID 19 disease
“In our small study we could not demonstrate any correlation between Ct values and severity of disease. Though patients with mild disease had lower Ct values and possibly higher viral loads they had also been tested earlier (median 3 days) than those with severe disease (median 5 days). However in patients with severe disease the Ct values of those who died were significantly lower than those who survived; but at the same time these patients had shorter duration of symptoms before testing (median 3 days as against 5 days). While it is difficult to draw conclusions from these results, it appears that time since onset of symptoms has a stronger relationship with the Ct values as compared to the severity of disease.”
“Recently the ability of Ct values to reflect the true viral load has been questioned . Experts state that the Ct values for a specimen vary between different kits and techniques (including target genes, primers and threshold fluorescence values) and Ct values may vary between different runs of the same kit.  The Ct value also depends on the method of collection of the sample and hence there may be variation in Ct values between two different samples obtained from the same person on the same day and run on the same kit. The Ct values also depend on the timing of sample collection in relation to onset of symptoms; samples collected earlier in the illness will have lower Ct values than those collected later in the illness . Therefore, the time of sampling since onset of illness has to be controlled while comparing Ct values between mild and severe disease. Our study proves the same point.”
What is interesting about this next study from June 2021 is the two instances where the researchers point out that there is a class of scientists who currently disagree with the use of PCR as the “gold standard” diagnostic tool for “SARS-COV-2.” Maybe the aforementioned scientists are ones who are intellectually honest and understand the severe limitations of the technology? The authors concluded that it is of the utmost importance to develop reliable and efficient methods to estimate “viral” load. They acknowledged that further studies are needed in order to depict the relationship between “viral” loads with viable “viruses” and disease severity/infectivity and that questions and knowledge gaps remain regarding any correlation between Ct values and disease severity. In other words, “viral” load estimates are absolutely meaningless:
Viral Dynamics and Real-Time RT-PCR Ct Values Correlation with Disease Severity in COVID-19
“Abstract: Real-time RT-PCR is considered the gold standard confirmatory test for coronavirus disease 2019 (COVID-19). However, many scientists disagree, and it is essential to understand that several
factors and variables can cause a false-negative test.”
“However, there are some ambiguities, such as whether it is best to use Ct values in predicting the level of infectivity and disease severity in patients infected with SARS-CoV-2. In addition, one class of scientists has questioned whether RT-PCR be termed a gold standard technique for the detection of SARS-CoV-2 infection [29,30].”
“In the future, there is an utmost need to develop reliable and efficient methods to estimate viral load, and further studies depicting the relationship between viral loads with viable viruses and disease severity/infectivity are also needed. It should also be considered that decisions about predicting the severity of disease, fatality rate, and viral dynamics should be based on a wide range of clinical parameters such as age, co-morbidities, and biomarkers, namely lymphocyte counts, C-reactive protein level, and D-dimer level, as there are several question marks and knowledge gaps associated with a positive correlation between Ct values and disease severity, which is yet to be explored.“
This study from July 2021 showed again that there is no difference between “viral” loads of asymptomatic and symptomatic “Covid” patients. Obviously, this would go against logic. If one has no symptoms, it would be assumed that they would have less “virus” in their bodies and those with symptoms would have more “virus” within them. However, this is demonstrated over and over again not to be the case. There are asymptomatic cases with high “viral” loads and severe cases with low “viral” loads:
Viral Load Difference between Symptomatic and Asymptomatic
COVID-19 Patients: Systematic Review and Meta-Analysis
“Results: Overall, 703 COVID-19 patients (553 symptomatic and 150 asymptomatic) were analyzed. Five investigations reported the mean age of patients, evidencing that asymptomatic patients were younger than symptomatic patients (34.0 vs. 40.3 years, respectively). Pooled data regarding the levels of expression of the RdRp gene revealed no significant difference between symptomatic and asymptomatic subjects. Similarly, no differences were observed comparing the mean Ct values for the E and N genes. Based on real-time RT-PCR data, no differences exist in the viral load between symptomatic and asymptomatic COVID-19 subjects considering Ct values for RdRp, E and N genes’ expression. Asymptomatic subjects may represent a reservoir of the infection and significantly contribute to the maintenance of the pandemic.”
“Our analysis evidenced that symptomatic and asymptomatic SARS-CoV-2 patients have the same viral load since no differences were observed in terms of mean Ct values for the RdRp, E and N genes among the two groups. As it was recommended by the World Health Organization (WHO), the RdRp, E and N genes represent the targets for the detection of SARS-CoV-2, specifically the E gene for first-line screening, the RdRp gene for the confirmatory assay and the N gene for the additional confirmatory assay .”
It is clear from the above sources that “viral” load is an utterly useless measure. Together, they are pretty damning. Yet, as a final nail in the coffin for how PCR can not be used to determine a so-called “viral” load, the Association for Public Health Laboratories released a rather informative guide in November 2020 from which I have provided a few highlights:
Is there variability in Ct values?
Short answer: Yes.
The number of cycles required for detectable amplification of viral RNA is dependent on a long list of variables beyond simply how much viral RNA is present in a patient specimen. The relative impacts of these variables on the Ct value differs between test platforms and can vary widely.
Variables that can impact Ct values include but are not limited to:
• Efficiency of the collection of specimen
• Time of collection of specimen after onset of infection
• Specimen type—matrix effect
• Specimen type – level of viral RNA in different specimen types (e.g., upper vs. lower respiratory tract) can differ between specimens from the same patient at the same time
• Storage and transport conditions of specimen prior to testing
• Age of specimen
• Nucleic acid extraction efficiency
• Amount of viral RNA in the specimen
• Nature of the target RNA and design of the primer/probe sequences
• Efficiency of the real-time PCR chemistry in the assay (singleplex, multiplex)
• Method for defining/determining Ct value
I can get a quantitative test for HIV, why can’t I get one for COVID-19?
Short answer: They are not currently commercially available in the US.
Quantitative viral load assays are specifically designed for this purpose. They are run on specimen types that mitigate the impact of variables on the Ct value and include controls and calculations to assess viral load. For example, an HIV quantitative viral load assay is performed on a blood specimen. This specimen is homogenous and can be collected in a very standardized manner. The real-time PCR assay used to calculate viral load includes a set of controls to “standardize” the specimen (e.g., a control for specimen adequacy) and a set of standards (i.e., known dilutions of virus for calibration). Ct values of the patient specimen are compared to those of the standard curve to calculate the viral load in a standardized specimen.
This type of assay is not yet available for SARS-CoV-2. Respiratory specimens are not homogeneous and are challenging to standardize. The collection process of a respiratory specimen does not lend itself to quantifying the amount of virus present. Each swab collection is different and does not assure that the same amount of sample is collected. Quality of specimen collection is impacted by other variables including the skill of the collector, which nostril is swabbed first, or whether the patient recently ate or drank. Many COVID-19 diagnostic real-time PCR assays do not include specimen adequacy controls, and those that do still lack the standardization necessary to calculate viral load.
Cts and infectiousness—can we infer one from the other?
Short answer: No.
There are a number of reasons that Ct values should not be used to determine how infectious someone is. The first relate to the nature of the available testing methods and the inherent variability of Ct values:
• The available assays are qualitative, not quantitative. Qualitative tests are not designed to provide an indication of possible infectivity.
• There are many variables that impact Ct value that are unrelated to the amount of viral RNA in a specimen (see
• The only method available for determining the presence of live virus in a specimen is inoculating the virus into cell culture to determine if the virus can grow there. This is a very insensitive and qualitative method, may not detect low levels of infectious virus and does not necessarily correlate with infectiousness.
There are also simply not enough data at this time to infer a correlation between detectable SARS-CoV-2 viral RNA and infectiousness. We do not know how much virus (as measured by detecting viral RNA) is needed in a respiratory specimen for a person to be able to transmit it to someone else. We also do not know what the “cutoff” is for a person to no longer be infectious (i.e., at what point the amount of virus in a person’s respiratory specimen is too little for them to be able to infect others).
Do Ct values correlate with viral load?
Short Answer: Often, but not always.
There is a relationship between Ct values and amount of virus in a patient specimen, but they are not equivalent. There are many variables that impact Ct values (see above). Although Ct may be used as a proxy for viral load, caution must be taken when interpreting in this manner. A high Ct value often correlates with a low viral load, but not always.
A specimen could have a very high viral load, but also a high Ct value (i.e., it took more cycles to detect the viral RNA) because the extraction was inefficient, the patient just drank something that inhibited the real-time PCR reaction, or the specimen was packaged inappropriately and reached a high temperature during transportation to the lab and the viral RNA in the specimen degraded in the heat.
Any specimen that generates a result that is defined as “positive” by the test manufacturer is considered positive. As with any diagnostic test, the result should be interpreted in the clinical context.
The process of viral replication and infection must be taken into consideration as well. If a specimen is collected very close to the time of the initial infection the viral load may be very low as the virus has not had a lot of time to replicate; a specimen collected in the coming days may have a much higher viral load. A specimen collected many days to weeks after the initial infection may have a low viral load, and viral RNA can be detectable for many weeks after infection in some patients. Limited epidemiological and culture data indicate that patients are not infectious more than 10-15 days post-onset of symptoms.
Can I compare a Ct value from one test method to another?
Ct values and cutoffs are assay- and method-specific. A specimen with a Ct of 35 by one assay will not necessarily have the same Ct value by other assays. These values can vary up to two to three logs from test to test due to how the tests are designed.1
There can be a difference in the relative sensitivities of FDA authorized tests which may also impact Ct values. According to comparison data recently published by FDA using a standard panel, there can be as much as a 1000-fold difference between the various assays.2“
That was yet another scathing warning regarding the use of Ct values to determine a so-called “viral” load. Perhaps it’s because of the scientific data (or lack thereof) that the CDC has also said the same regarding Ct values and “viral” load.
According to a CDC study:
“The exact RT-PCR Ct values associated with the presence of infectious SARS-CoV-2 is unknown“
According to the CDC Q & A:
Q. Can cycle threshold (Ct) values be used to access when a person is no longer infectious?
A. No. Although attempts to culture virus from upper respiratory specimens have been largely unsuccessful when Ct values are in high but detectable ranges, Ct values are not a quantitative measure of viral burden. In addition, Ct values are not standardized by RT-PCR platform nor have they been approved by FDA for use in clinical management. CDC does not endorse or recommend use of Ct values to assess when a person is no longer infectious.“
The CDC understands as well that there can be no correlation between Ct values, “viral” load, and disease severity/infectivity. The data does not exist and what is out there contradicts their narrative. However, even though they admit that there is no correlation, this does not stop the CDC/WHO/MSM from constantly using “viral” load to drum up evidence-less and inaccurate headlines/conclusions in order to generate fear.
- Studies have found little difference between the “viral” loads of patients who show symptoms and those who don’t
- Scientists also haven’t found much difference in the “viral” loads of adults versus children
- Cycle threshold values used to determine “viral” load can vary widely depending on how a sample is collected and how quickly it gets analyzed
- One small study from India could not demonstrate any correlation between Ct values and severity of disease
- Patients with mild disease had lower Ct values and possibly higher “viral” loads
- The ability of Ct values to reflect the true “viral” load has been questioned
- Experts state that the Ct values for a specimen vary between different kits and techniques (including target genes, primers and threshold fluorescence values) and Ct values may vary between different runs of the same kit
- Many scientists are disagreeing that RT-PCR should be considered the gold standard confirmatory test
- There is an utmost need to develop reliable and efficient methods to estimate “viral’ load, and further studies depicting the relationship between “viral” loads with viable “viruses” and disease severity/infectivity are also needed
- There are several question marks and knowledge gaps associated with a positive correlation between Ct values and disease severity, which is yet to be explored
- A meta-analysis revealed, based on real-time RT-PCR data, that no differences exist in the “viral” load between symptomatic and asymptomatic “COVID-19” subjects considering Ct values for RdRp, E and N genes’ expression
- Their analysis showed symptomatic and asymptomatic “SARS-CoV-2” patients have the same “viral” load
- According to the Association for Public Health Laboratories, there is wide variability in Ct values and they are dependent on a long list of variables beyond simply how much “viral” RNA is present in a patient specimen
- These include Pre-analytic Variables such as:
- Efficiency of the collection of specimen
- Time of collection of specimen after onset of infection
- Specimen type—matrix effect
- Specimen type – level of viral RNA in different specimen types (e.g., upper vs. lower respiratory tract) can differ between specimens from the same patient at the same time
- Storage and transport conditions of specimen prior to testing
- Age of specimen
- They also include Analytic Variables such as:
- Nucleic acid extraction efficiency
- Amount of “viral” RNA in the specimen
- Nature of the target RNA and design of the primer/probe sequences
- Efficiency of the real-time PCR chemistry in the assay (singleplex, multiplex)
- Method for defining/determining Ct value
- Quantitative assays are not yet available for “SARS-CoV-2”
- Respiratory specimens are not homogeneous and are challenging to standardize
- The collection process of a respiratory specimen does not lend itself to quantifying the amount of “virus” present
- Many “COVID-19” diagnostic real-time PCR assays do not include specimen adequacy controls, and those that do still lack the standardization necessary to calculate “viral” load
- The APHL admits there are a number of reasons that Ct values should not be used to determine how infectious someone is
- They claim cell culture is a very insensitive and qualitative method, may not detect low levels of infectious “virus” and does not necessarily correlate with infectiousness
- It is not known how much “virus” (as measured by detecting “viral” RNA) is needed in a respiratory specimen for a person to be able to transmit it to someone else
- It is also not known what the “cutoff” is for a person to no longer be infectious
- Ct values and “viral” loads are not equivalent and do not always correlate
- Although Ct may be used as a proxy for “viral” load, caution must be taken when interpreting in this manner
- A specimen with a Ct of 35 by one assay will not necessarily have the same Ct value by other assays
- According to comparison data recently published by FDA using a standard panel, there can be as much as a 1000-fold difference between the various assays
- The CDC has stated that the exact RT-PCR Ct values associated with the presence of infectious “SARS-CoV-2” is unknown
- The CDC also states:
- Ct values are not a quantitative measure of “viral” burden
- Ct values are not standardized by RT-PCR platform nor have they been approved by FDA for use in clinical management
- It does not endorse or recommend use of Ct values to assess when a person is no longer infectious
Kary Mullis, the creator of the PCR test, repeatedly warned against using his invention as a quantitative measurement of “viral” burden:
“Kary Mullis … is thoroughly convinced that HIV is not the cause of AIDS. With regard to the viral-load tests, which attempt to use PCR for counting viruses, Mullis has stated:
“Quantitative PCR is an oxymoron.” PCR is intended to identify substances qualitatively, but by its very nature is unsuited for estimating numbers. Although there is a common misimpression that the viral-load tests actually count the number of viruses in the blood, These tests cannot detect free, infectious viruses at all; they can only detect proteins that are believed, in some cases wrongly, to be unique to HIV. The tests can detect genetic sequences of viruses, but not viruses [(29), p. 3].”
“I think misuse PCR is not quite, I don’t think you can misuse PCR. The results, the interpretation of it, If they could find this virus in you at all, and with PCR, if you do it well, you can find almost anything in anybody. It starts making you believe in the sort of Buddhist notion that everything is contained in everything else. Right, I mean, because if you can amplify one single molecule up to something which you can really measure, which PCR can do, then there’s just very few molecules that you don’t have at least one single one of them in your body, okay. So that could be thought of as a misuse of it, just to claim that it’s meaningful.”
“It’s [PCR] just a process that’s used to make a whole lot of something out of something. That’s what it is. It doesn’t tell you that you’re sick and it doesn’t tell you that the thing you ended up with really was going to hurt you or anything like that.”
He would have torn these studies and articles apart were he alive today. It’s clear that “viral” load estimates are inaccurate, are not standardized, are influenced by numerous variables outside of the quantity of RNA, and that they have no correlation to disease severity/infectivity.
Don’t fall for their lies.
It’s time to flush virology down the toilet with the rest of the crap.