At-home COVID-19 antigen tests could detect omicron effectively

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In a new study from the University of Massachusetts Medical School, researchers found that at-home antigen tests performed similarly in detecting omicron and delta coronavirus variants in comparison to polymerase chain reaction (PCR) tests.

At-home antigen tests are valuable tools to inform people of their infection status quickly.

Previous reports suggested that there is decreased and delayed sensitivity of at-home antigen tests in detecting the omicron variant in comparison to PCR tests.

The current study reveals that the early reports are overstated.

In fact, this analysis found that at-home antigen tests performed slightly better in detecting omicron variant infections, versus delta, within 48 hours of testing positive on a molecular PCR test.

In the current study, the team examined used data from 5,726 participants in a prospective cohort study that is part of NIH’s RADx initiative, Test Us At Home.

Researchers assessed differences in performance of at-home antigen tests for detecting delta and omicron variants by measuring two factors: the likelihood of a positive result from an at-home antigen test compared with a PCR test, and the likelihood of a participant testing positive on an at-home antigen test based on the number of days since the first positive PCR test.

Researchers also factored in a measure reflecting the level of virus present in a sample, so they could compare how the different test methods performed for a given viral load.

They found that during the test period, 281 participants tested positive for SARS-CoV-2 using PCR testing. Two-thirds of these positive tests were the omicron variant and one-third were delta.

82% of delta-infected individuals and 92% of omicron-infected individuals tested positive by at-home antigen test within 48 hours of their first positive PCR test.

The findings suggest that in a world where there is still a testing shortage and PCR tests could take days to get results, at-home antigen tests perform relatively well delivering results in 15 minutes or less.

They offer a tool that’s helpful to bring the surge volumes down.

If you care about COVID, please read studies about drugs that may reduce COVID-19 vaccine effectiveness, and rapid test for detecting COVID-19 highly accurate.

For more information about COVID, please see recent studies about the most effective face-mask practices to reduce spread of COVID-19, and results showing that scientists find antibodies that can neutralize Omicron.

The study was conducted by Apurv Soni et al., and published in medRxiv.

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