Coronavirus PCR test accuracy ‘may vary by time of day,’ new study finds
March 24, 2021 (LifeSiteNews) – The accuracy of coronavirus PCR tests “may vary by time of day,” according to a new study. In an analysis of 31,094 results from PCR throat swab tests, researchers from Vanderbilt University found “a two-fold variation in test sensitivity” based on the time that the swabs were administered.
Tests were most likely to come back positive when taken around 2 p.m., the researchers said in a pre-print paper published on medRxiv earlier this month. The skewed pattern “suggests a cyclic pattern in viral shedding, with a peak in the early afternoon,” they added.
“Such temporal considerations may be leveraged to maximize the effectiveness of non-pharmaceutical intervention strategies,” the authors commented. “That could entail emphasizing midday to early-afternoon masking at home while isolating,” Reuters said.
The Vanderbilt paper is the latest of several studies that have exposed significant accuracy issues of the “gold-standard” PCR testing method for coronavirus. Last year, a paper published in the BMJ reported that PCR throat swab tests may have a mere 32 percent sensitivity rate and nasal swabs might have only 63 percent accuracy.
A study highlighted by the U.S. Centers for Disease Control (CDC) in November likewise found that PCR tests missed nearly half of all positive Wuhan virus cases among students tested for the virus one time. Another pre-print article published in medRxiv in April said the PCR method may yield false negatives for up to 29 percent of patients.
Leading scientists also have raised concerns about false positives from PCR tests. “The PCR-based system routinely reports positivity values exceeding the absurd, and these are accepted without comment,” Mike Yeadon, former vice president of coronavirus vaccine-maker Pfizer, has said. “This has been allowed to happen because the assumption is that PCR is high science and cannot be far wrong. Nothing can be further from the truth.”
Substantial accuracy issues also have been noted for other testing methods, as the CDC and U.S. Food and Drug Administration (FDA) have admitted.
Coronavirus tests nevertheless increasingly have become a mandatory precondition for returning to normal life. Test results have been required for in-person work, academic study – even off-campus – and essential medical treatment at hospitals in recent months.
Since January, Canadian officials repeatedly have detained citizens re-entering the country without PCR coronavirus test results.
“Our rights are slipping right before our eyes and our freedoms are being stripped,” said a pastor whose wife was detained in an undisclosed facility last month after she presented results from the wrong type of Wuhan virus test. “It’s time to wake up.”