Photo courtesy of phila.gov.
By Erin Maxwell || Editor-in-Chief
For those not exhibiting symptoms, testing shows the Rapid COVID-19 test identifies the coronavirus 58% of the time. For those with symptoms, that number is 92%. Even scarier, the Food and Drug Administration acknowledged earlier this year that the tests may be ineffective at detecting the omicron variant, which remains the dominant strain in much of the United States.
Rapid tests are much more accessible to the consumer, especially as medical facilities continue to struggle with PCR test shortages. Without insurance, rapid tests will run you around $20 for a pack of two, as compared to the $150 for a PCR.
The PCR test is considered the gold standard, as it seeks out any genetic material evidence from the coronavirus and is much more sensitive. The rapid antigen test, also called the lateral flow test, targets the antigen, which is a type of protein on the surface of the virus. However, there have to be enough antigens in a person’s system for the test to pick up on them- a few floating around won’t do the trick. Also, a person’s viral load fluctuates wildly over time, so a negative test result could be a positive one within even a 12 hour period. As Pablo Penaloza-MacMaster, a viral immunologist at Northwestern’s medical school says, “at-home tests are most effective when the person has high viral loads,” which can easily change. Still, false-positive results are extremely rare. The biggest risk is not catching the positive test, instead of accidentally getting a positive result. If you test positive, you have it- if you test negative, you may or may not.
So what should we do? Public health experts aren’t willing to give up on the rapid tests, which can be a vital and accessible source of information, and are accurate a majority of the time. Instead, they suggest taking tests serially- that is, repeatedly and over a course of about a week. The best rule of thumb is to aim for five days after your potential exposure, as COVID-positive individuals usually have enough viral load to be detected at that stage.
The bottom line: don’t dump the tests just because they might not catch every antigen at every stage. Instead, use tests as a tool to guide your decisions, and don’t treat them as a one-and-done deal.
Erin Maxwell is a junior and the Editor-in-Chief for The College Reporter. Her email is firstname.lastname@example.org.