We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress hp
Sign In
Advertise with Us

Download Mobile App





COVID-19 Rapid Tests Perform on Par with PCR Tests, Finds New Study

By LabMedica International staff writers
Posted on 02 Jul 2021
Rapid antigen tests perform on par with lab tests when used every three days, according to a new screening study, thus building the case for frequent COVID-19 antigen testing.

Researchers at the National Institutes of Health (NIH; Bethesda, MD, USA) have found that detecting SARS-CoV-2, the virus that causes COVID-19, improves with regularity of testing, whether using rapid antigen tests or PCR molecular tests. More...
The PCR test is considered the gold standard for diagnosing COVID-19 infection, but cost and infrastructure issues, as well as wait times for PCR results, have limited its use more broadly as a screening tool for asymptomatic people because rapid results are needed to interrupt the chain of transmission.

In the highly anticipated study, researchers affiliated with the NIH’s Rapid Acceleration of Diagnostics (RADx) initiative compared rapid antigen and laboratory PCR approaches for COVID-19 serial screening and reported results from 43 people infected with the virus. The researchers compared three COVID-19 viral testing modalities - PCR testing of saliva, PCR testing of nasal samples and rapid antigen testing of nasal samples. The researchers calculated the sensitivity of each test modality to detect SARS-CoV-2 and measured the presence of live virus over a two-week period following initial infection. They found that PCR molecular tests - both from saliva and nasal samples - are more sensitive than rapid antigen tests at detecting the SARS-CoV-2 virus prior to the infectious period. If the result from PCR tests could be quickly returned, the person receiving the result could undertake measures much sooner to prevent transmitting the virus to others. Unfortunately, results from PCR are rarely returned the day of testing.

The authors calculated test sensitivity based on test frequency, finding that a cadence of tests every three days achieved better than 98% sensitivity to detect infection, whether using rapid antigen tests or PCR tests. When they assessed frequency of testing once per week, nasal and saliva PCR testing sensitivity remained high, at around 98%, but antigen test sensitivity declined to 80%. These results show, for the first time, that testing at least twice per week with rapid antigen tests has comparable performance with PCR testing and maximizes the likelihood of detecting people infected with SARS-CoV-2. The sensitivity of PCR molecular tests and rapid antigen tests is highest when viral cultures are positive for SARS-CoV-2, as might be expected. Even beyond this infectivity period, though, PCR tests continue to detect particles of virus, when the virus is most likely no longer transmissible. Because antigen tests at the point of care or at home can deliver immediate results and are less costly than laboratory tests, these results suggest that they could be a highly effective screening tool to prevent disease outbreaks.

“Rapid antigen testing at home, two to three times per week, is a powerful and convenient way for individuals to screen for COVID-19 infection,” said Bruce Tromberg, Ph.D., director of the National Institute of Biomedical Imaging and Bioengineering (NIBIB), part of NIH. “With schools and businesses reopening, an individual’s risk of infection can change from day to day. Serial antigen testing can help people manage this risk and quickly take action to prevent spread of the virus.”

“Silent transmission of the SARS-CoV-2 virus from individuals with no symptoms contributes significantly to the spread of the virus,” said co-author William Heetderks, M.D., Ph.D., a RADx Tech program advisor at NIBIB. “Faster, cheaper and broader testing with antigen tests can be a big help in the kind of large-scale screening scenarios that can find these silent transmitters.”

Related Links:
National Institutes of Health


Gold Member
SARS‑CoV‑2/Flu A/Flu B/RSV Sample-To-Answer Test
SARS‑CoV‑2/Flu A/Flu B/RSV Cartridge (CE-IVD)
Portable Electronic Pipette
Mini 96
New
ESR Analyzer
TEST1 2.0
New
Gold Member
Collection and Transport System
PurSafe Plus®
Read the full article by registering today, it's FREE! It's Free!
Register now for FREE to LabMedica.com and get access to news and events that shape the world of Clinical Laboratory Medicine.
  • Free digital version edition of LabMedica International sent by email on regular basis
  • Free print version of LabMedica International magazine (available only outside USA and Canada).
  • Free and unlimited access to back issues of LabMedica International in digital format
  • Free LabMedica International Newsletter sent every week containing the latest news
  • Free breaking news sent via email
  • Free access to Events Calendar
  • Free access to LinkXpress new product services
  • REGISTRATION IS FREE AND EASY!
Click here to Register








Channels

Molecular Diagnostics

view channel
Image: The study has linked blood proteins to Alzheimer’s disease and memory loss (Photo courtesy of Shutterstock)

Blood Test Could Detect Proteins Linked to Alzheimer's Disease and Memory Loss

Alzheimer’s disease has long been associated with sticky amyloid plaques in the brain, but these markers alone do not fully explain the memory loss and cognitive decline patients experience.... Read more

Hematology

view channel
Image: New research points to protecting blood during radiation therapy (Photo courtesy of 123RF)

Pioneering Model Measures Radiation Exposure in Blood for Precise Cancer Treatments

Scientists have long focused on protecting organs near tumors during radiotherapy, but blood — a vital, circulating tissue — has largely been excluded from dose calculations. Each blood cell passing through... Read more

Pathology

view channel
Image: An adult fibrosarcoma case report has shown the importance of early diagnosis and targeted therapy (Photo courtesy of Sultana and Sailaja/Oncoscience)

Accurate Pathological Analysis Improves Treatment Outcomes for Adult Fibrosarcoma

Adult fibrosarcoma is a rare and highly aggressive malignancy that develops in connective tissue and often affects the limbs, trunk, or head and neck region. Diagnosis is complex because tumors can mimic... Read more

Technology

view channel
Image: Conceptual design of the CORAL capsule for microbial sampling in the small intestine (H. Mohammed et al., Device (2025). DOI: 10.1016/j.device.2025.100904)

Coral-Inspired Capsule Samples Hidden Bacteria from Small Intestine

The gut microbiome has been linked to conditions ranging from immune disorders to mental health, yet conventional stool tests often fail to capture bacterial populations in the small intestine.... Read more
Copyright © 2000-2025 Globetech Media. All rights reserved.