April 6, 2021
Professor of Practice in Biomedical Diagnostic, Arizona State University
Since their approval, much of the COVID-19 discourse has been around vaccines. Citizens have eagerly awaited getting vaccinated to start the process of a return to normalcy. However, testing for COVID-19 still needs to be prioritized because it is an effective method for combatting the virus — especially for companies that will have employees return to the office and use testing to keep their employees safe.
Many people have concerns and curiosities regarding COVID-19 testing, from its accuracy to its demand in the workplace. Here are four common questions about COVID-19 testing — answered.
Rapid COVID-19 Testing Rarely Gives False Positives and Has a Low Percentage of False Negatives
One of the most common questions about COVID-19 testing is how accurate rapid tests really are. Mara Aspinall, managing director of Health Catalysts Group and professor of practice in biomedical diagnostics at Arizona State University, noted that most rapid tests are called “antigen tests” and have a high accuracy rate.
“Most of the antigen tests [are] pretty close to 100% sensitive, i.e., very, very few, if any, false positives,” Aspinall said. “Their challenge is that they could be between 95% and 98% sensitive, meaning they have [2 to 5%] false negatives.”
COVID-19 Tests Do Detect New Variants of the Virus
With so many new variants of the COVID-19 virus, Aspinall reassured the public that testing does detect these variants.
“The antigen tests … focus on what's called the N protein,” she said. “The variants to date have been on these S proteins, but the antigen tests test on the N protein as nuclear capsid, and they are still just as effective. You will get an [accurate test result] whether you have the Wuhan strain, whether you have the UK variant, the South African variant, [or] the Brazilian variant.”
The only thing it won’t tell you, she continued, is which variant you contracted.
Only Individuals With COVID-19 Symptoms Need to Be Tested After They Are Fully Vaccinated
“[If you are vaccinated], the CDC has made clear that even if you're exposed, [or], you believe you're exposed to COVID-19, you do not need to quarantine and you do not need to test unless you're symptomatic,” said Aspinall. “If you begin to feel symptoms of any type, and there are a broad range of symptoms for COVID-19, then indeed you should test.”
“The mRNA vaccines [from] Pfizer and Moderna have between 90% and 92% effectiveness in real-world situations,” Aspinall continued. “In the clinical trials, they were 94% and 95%.”
Because of the slim chance of still contracting the virus, she said, “If [testing] is part of a broad screening program in a school or in an office environment … I would recommend putting fully vaccinated people into that testing regimen.”
Aspinall added that while you still can get COVID-19 after being vaccinated, “the likelihood of you having a severe case is virtually zero because both vaccines were essentially 100% [effective] in preventing aggressive disease, hospitalization or death.”
Employers Should Prepare for Routine Testing in the Post-Pandemic Workplace
“It's all about telling people that they have the power to do it,” said Aspinall. “They have the power in themselves … to control this pandemic.”
She added that employers should reassure employees that testing is quick and easy — it won’t take up more than three minutes of their day. Additionally, since the cost of testing has decreased dramatically, it won’t cause any financial stress on businesses.
“The last thing that I would add as an employer is [to] emphasize confidentiality and [understand] this is not something that you would target one part of the company or another,” Aspinall continued. “Do it broadly, not for parts of the company, so everybody's in on it and it's done quickly and that you will keep the information confidential.”
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