What is a rapid test?: An antigen-based COVID-19 test, often called a rapid test, can be purchased over the counter (online or in a pharmacy) and taken at home. It works by searching for protein pieces of the COVID-19 virus. Depending on the test, either a sample from the nose or mouth is obtained via a swab, then placed into a solution. In most kits, you put a few drops of the solution plus sample into a test disc and wait ~ 15 minutes. If the test is positive, there will be two-colored lines, the control line and the test line. If the test is negative, only the control line will be positive.
It is important to note that rapid antigen tests are less sensitive than polymerase chain reaction (PCR) tests which amplify even very tiny amounts of viral genetic material and thus rapid tests might be negative very early on in an infection. Also, whereas a PCR test can stay positive for weeks to months, even after you are no longer contagious, a rapid test will become negative once the virus count has dropped below the level of infectivity.
What does it mean if a test has been ‘authorized’, ‘unauthorized’, ‘approved’ or ‘unapproved’?: One of the responsibilities of the Federal Drug Administration (FDA) is ensuring that vaccines and medical devices are safe and effective. In order for a medical device, such as a COVID-19 test, to be deemed safe and effective it must undergo an extensive review. This time-consuming process is required for full FDA approval. If a product is needed urgently, though, it may undergo an expedited review; those that pass this more rapid review receive what is called an emergency use authorization (EUA).
Currently, none of the COVID-19 rapid antigen tests have received full FDA approval, but many have been authorized for emergency use. The FDA maintains an updated list of antigen and molecular diagnostic tests for SARS-CoV-2 which have received EUA: In Vitro Diagnostics EUAs - Antigen Diagnostic Tests for SARS-CoV-2 | FDA.
It is particularly important to check the list of authorized products if you are buying a rapid test online, as the internet is rife with fraudulent and unauthorized tests. Most recently, on March 1st 2022, the FDA issues safety notices warning against use of unauthorized rapid tests made by ACON Laboratories, SD Biosensor and Celltrion.
How much does a rapid test cost?: The out-of-pocket cost of rapid antigen COVID-19 tests varies, averaging ~ $15-20 per kit (two tests per kit). Thankfully, the government has ramped up the accessibility of free rapid COVID-19 tests. In January 2022, all US households became eligible to request a one-time order of four free rapid COVID-19 tests, either via the website COVIDTests.gov or by calling 800-232-0233. At his State of the Union address, President Biden announced that Americans would be able to receive a second set of free rapid tests; four more per household for those who already ordered one set and eight tests (two sets) for those who haven't yet ordered. Private health insurers are also mandated to cover up to eight at-home antigen tests per month, per covered individual, with reimbursement capped at $12 per testing kit (two tests per kit). The insurance provider will usually cover the upfront cost for in-network pharmacies and retroactively reimburse members who buy test kits from out-of-network pharmacies. Original Medicare beneficiaries will be able to receive up to 8 free over-the-counter COVID-19 tests in the early spring of 2022. In the meantime, they can obtain free at-home tests from community health centers and Medicare-certified health clinics.
