Rapid COVID-19 Tests Efficacy, Trustworthiness, and Timing of Results Against Omicron BA.2 Subvariant Analyzed

Rapid at-home antigen tests have become the first-choice diagnostic tool for many people who think they might be infected with COVID-19.

This comes after reports of COVID-19 cases slowly ticked up in the United States, with the Omicron BA.2 subvariant currently the dominant strain in the country, an NPR report specified.

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While such rapid tests are useful for detecting the transmission of the virus, the high infectivity of this particular subvariant and concerns around self-reporting has given rise to numerous questions.

Experts have said antigen tests are working against BA.2, although there are some caveats. Even though it's long been known that rapid tests have a lower degree of preciseness than the standard PCR test, there is no specification that they are any less efficient when it comes to detecting BA.2 compared to strains that have ever been seen.

At-Home Rapid Antigen Tests

Dr. Celine Grounder, a senior editor and editor-at-large for public health at Kaiser Health News, said rapid tests might take longer to produce positive results.

Typically, there's a day or two delays between when an individual might test positive on a PCR against when one might test positive on one of these at-home rapid antigen tests; Gounder explained and added, they do work to pick up an infected and when they need to be used often.

Nonetheless, according to physician and bioengineer Dr. Wilbur Lam, who's working with the federal government to analyze COVID-19 diagnostic tests, given the higher infectivity of BA.2, there's a chance that the virus might infect other people before a positive result comes out from a rapid test.

Lam elaborated that one aspect of the Omicron variant, which includes the BA.2 subvariant, is biological and is likely more infective than the other previous strains.

Therefore, as indicated in a similar WBHM.org report, the test might not even have time to pick it up before it jumps from one patient to another.

Serial Testing

Nonetheless, rapid antigen tests have the edge of being widely available and producing a result within minutes, Lam said, adding that the key to using them efficiently against the subvariant is to test early and often.

Since these things are more available than PCR testing, each individual can test himself serially if able to get hold of them. Lam also explained that people need to test multiple days following the onset of COVID-19 symptoms.

Serial testing, in particular, does end up mitigating the disadvantages of at least the preciseness of these test types compared to PCR tests.

Some people may find they experience symptoms consistent with an infection from COVID-19, although they are still testing negative from rapid tests.

Omicron BA.2 Subvariant

At-home tests may make it easier for individuals to detect a COVID-19 infection, but the data might not reflect actual infection rates if there is an absence of self-reporting.

This is an important issue for the governmental, public health, and medical communities are just currently addressing, said Lam.

In fact, the present number of cases of BA.2, which is detailed in a related BBC News report, may be underestimating the figures since a considerable number of positive cases are either self-detected or unreported.

More so, while some rapid tests provide smartphone apps to help people self-report a positive result, there is no requirement to do so.

A related report about COVID-19 repaid test is shown on Alberta Health Services' YouTube video below:

Check out more news and information on COVID-19 Tests in Science Times.