Dear Editor
A CDC paper of June 2020, entitled, ’Severe Acute Respiratory Syndrome Coronavirus 2 from Patient with Coronavirus Disease, United States’, describes the results of experimentally attempting to infect cell culture lines with clinically-obtained “SARS-CoV-2” virus samples:
“Therefore, we examined the capacity of SARS-CoV-2 to infect and replicate in several common primate and human cell lines, including human adenocarcinoma cells (A549), human liver cells (HUH 7.0), and human embryonic kidney cells (HEK-293T). In addition to Vero E6 and Vero CCL81 cells. ... Each cell line was inoculated at high multiplicity of infection and examined 24h post-infection. No CPE was observed in any of the cell lines except in Vero cells, which grew to greater than 10 to the 7th power at 24 h post-infection. In contrast, HUH 7.0 and 293T showed only modest viral replication, and A549 cells were incompatible with SARS CoV-2 infection.”(1)
However, the 13th July 2020 CDC paper, entitled, ‘CDC 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel For Emergency Use Only Instructions for Use’, stated that: “Since no quantified virus isolates of the 2019-nCoV are currently available, assays designed for detection of the 2019-nCoV RNA were tested with characterized stocks of in vitro transcribed full length RNA (N gene; GenBank accession: MN908947.2) of known titer (RNA copies/μL) spiked into a diluent consisting of a suspension of human A549 cells and viral transport medium (VTM) to mimic clinical specimen.”(2)
It appears, therefore, that despite knowing that the virus obtained from, “Patient with Coronavirus Disease”, could not be demonstrated to exhibit a cytopathic effect (CPE) in the human cell culture line A549 (human lung alveolar adenocarcinoma cells), the very same cell line was subsequently genetically modified to,”mimic clinical specimen”, in order to develop a RT-PCR test for SARS-CoV-2/’Covid-19’.
Given that there was no prior evidence of lethality of the clinically-obtained virus in human cells, why was a test developed on the basis that it was a dangerous pathogen causing a life-threatening disease? And why was the same cell culture line used which had already been demonstrated to be uninfectable by the virus?
In addition, the CDC stated,” We have made the virus isolate available to the public health community by depositing it into 2 virus reagent repositories”. (1).
In which case, why did Public Health England state that they had no cultivable clinical samples or direct evidence of viral isolation? (3).
Rapid Response:
Re: Covid-19: Ignoring the knowns
Dear Editor
A CDC paper of June 2020, entitled, ’Severe Acute Respiratory Syndrome Coronavirus 2 from Patient with Coronavirus Disease, United States’, describes the results of experimentally attempting to infect cell culture lines with clinically-obtained “SARS-CoV-2” virus samples:
“Therefore, we examined the capacity of SARS-CoV-2 to infect and replicate in several common primate and human cell lines, including human adenocarcinoma cells (A549), human liver cells (HUH 7.0), and human embryonic kidney cells (HEK-293T). In addition to Vero E6 and Vero CCL81 cells. ... Each cell line was inoculated at high multiplicity of infection and examined 24h post-infection. No CPE was observed in any of the cell lines except in Vero cells, which grew to greater than 10 to the 7th power at 24 h post-infection. In contrast, HUH 7.0 and 293T showed only modest viral replication, and A549 cells were incompatible with SARS CoV-2 infection.”(1)
However, the 13th July 2020 CDC paper, entitled, ‘CDC 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel For Emergency Use Only Instructions for Use’, stated that: “Since no quantified virus isolates of the 2019-nCoV are currently available, assays designed for detection of the 2019-nCoV RNA were tested with characterized stocks of in vitro transcribed full length RNA (N gene; GenBank accession: MN908947.2) of known titer (RNA copies/μL) spiked into a diluent consisting of a suspension of human A549 cells and viral transport medium (VTM) to mimic clinical specimen.”(2)
It appears, therefore, that despite knowing that the virus obtained from, “Patient with Coronavirus Disease”, could not be demonstrated to exhibit a cytopathic effect (CPE) in the human cell culture line A549 (human lung alveolar adenocarcinoma cells), the very same cell line was subsequently genetically modified to,”mimic clinical specimen”, in order to develop a RT-PCR test for SARS-CoV-2/’Covid-19’.
Given that there was no prior evidence of lethality of the clinically-obtained virus in human cells, why was a test developed on the basis that it was a dangerous pathogen causing a life-threatening disease? And why was the same cell culture line used which had already been demonstrated to be uninfectable by the virus?
In addition, the CDC stated,” We have made the virus isolate available to the public health community by depositing it into 2 virus reagent repositories”. (1).
In which case, why did Public Health England state that they had no cultivable clinical samples or direct evidence of viral isolation? (3).
(1) https://wwwnc.cdc.gov/eid/article/26/6/20-0516_article
(2) https://www.fda.gov/media/134922/download
(3) https://www.whatdotheyknow.com/request/679566/response/1625332/attach/ht...
Competing interests: No competing interests