A guest on The Joe Rogan Experience podcast has made several misleading claims about COVID-19 reinfection and PCR tests, including one that people cannot catch the disease twice.
In a video clip seen by thousands (here, here, here, here), American cardiologist Dr Peter McCullough claims the U.S. Centers for Disease Control and Prevention (CDC) “admitted” through a Freedom of Information (FOI) request that COVID-19 cannot be caught twice.
McCullough also claims those who have tested positive twice, of which there are “about 100 purported cases”, must have received false positives or be carrying “dead virus” after infection.
He goes on to claim that no COVID-19 reinfection cases met a “rigorous” testing criterion. He suggests this would consist of a positive PCR at a “low cycle threshold, less than 28”, a positive “antigen immuno-assay test, so the nucleocapsid is there” and sequencing of the virus after initial infection, as well as six months later during suspected reinfection.
However, a CDC spokesperson told Reuters the FOI request in question did not solely concern COVID-19 reinfections.
The request regarded “any documented case of an individual who never received a vaccine for COVID-19, and after a reinfection (second positive case after recovery from COVID-19) transmitted SARS-CoV-2 to another person”, they said.
Due to privacy protections, the CDC could not share more information on the individual case.
COVID-19 reinfection cases remain rare but have been reported, according to the CDC (here).
The CDC spokesperson pointed Reuters to studies it has published demonstrating suspected reinfections.
One of the studies found five residents of a Kentucky nursing facility received positive SARS-CoV-2 nucleic acid test results in two separate COVID-19 outbreaks three months apart (here). The individuals had received at least four negative test results between the two outbreaks, suggesting reinfection, it says.
Another CDC study showed unvaccinated people were more than twice as likely to get reinfected in comparison to vaccinated individuals (https:/www.cdc.gov/mmwr/volumes/70/wr/mm7032e1.htm).
A November 2021 study published in the New England Journal of Medicine confirmed 1,304 reinfections among 353,326 people who contracted COVID-19 in Qatar (here). Most of those reinfected had mild disease.
Experts at Meedan Health Desk, a group of public health scientists working to tackle medical misinformation, affirmed that there is documented evidence of reinfection with SARS-CoV-2.
Data is limited, however, on the frequency and outcomes of reinfection.
“While getting sick with the virus might help us gain some immunity from another COVID-19 infection, it is unknown how long that immunity lasts,” Meedan’s said health experts in an email to Reuters.
“People who have been infected with SARS-CoV-2 can potentially get infected within a few months. Reinfection and its severity also depend on individual susceptibility.”
They also pointed to documented evidence of COVID-19 reactivation, or “relapse”, in which a person who appears to have recovered still has small amounts of “dormant virus” that becomes active again, reactivating symptoms (here, here).
Meedan’s experts explained: “Differentiating reactivation from reinfection is difficult because scientists can only truly identify reactivation if patients give samples during their first episode of illness, which are then kept and sequenced genetically.
“Because these types of tests are not often done it’s difficult to know how common COVID-19 reactivation is.”
One small May 2021 study found 29 out of 109 patients experienced reactivation (here).
Prolonged viral shedding -- separate to reactivation as symptoms do not return -- can also be confused with reinfection, Meedan Health Desk told Reuters.
“While the viral load of COVID appears to peak in the first week of illness, viral shedding from the upper respiratory tract has occurred up to 83 days later,” they said.
The CDC did not respond to Reuters questions about how it confirms COVID-19 reinfections.
McCullough also claims in the video that the CDC said its methodology for PCR tests early in the pandemic could not distinguish between the flu and COVID-19, resulting in false positives.
However, the CDC did not say that PCR tests could not distinguish between influenza and COVID-19, as Reuters previously reported (here).
A July 2021 CDC update suggesting PCR tests for SARS-CoV-2 should be phased out by the end of the year was misinterpreted. The agency said it was opting for multiplex tests (that can detect both viruses) to save time and resources.
Previous Reuters reports (here) suggest PCR tests work by detecting the genetic sequences of viruses, not the viruses themselves, adding, “PCR test for COVID-19 detects the presence of the RNA of the virus in the swab sample.”
False and misleading. The FOI request to the CDC concerned documented cases of unvaccinated people becoming reinfected with COVID-19 and transmitting the virus to another person. There are documented cases of reinfection, however they remain relatively rare. Challenges with confirming reinfections include virus reactivation and prolonged viral shedding.
This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here.
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