There are two main types of diagnostic coronavirus tests easily available: the PCR and the rapid antigen. The PCR is often called the gold standard of tests and is more sensitive to the presence of the virus. The rapid antigen test can be administered at home and isn’t as sensitive. It may seem obvious then that people should always choose the PCR test and avoid the rapid antigen test, because why not choose the gold standard? In fact, both these tests have their place in the current Covid landscape because of their different sensitivities. We share the basic facts of the available Covid-19 tests so that seniors and caregivers in San Diego can choose the best test for their needs.
When the vaccine was still a faint hope and most testing was done in the hospital, we had few options for protection other than quarantine and masks. Now, we can travel, visit family, and attend public and private events but proof of vaccination and a negative Covid test are often required to participate. As Omicron spreads rapidly, a negative test can give employees the confidence to safely return to work after exposure or infection. The burden of getting tested is on the would-be travelers, visitors, revelers, and workers. There are two main diagnostic test types available and there is a right choice for each of these situations.
Current Covid-19 tests are either molecular, aka the PCR (polymerase chain reaction) test, or antigen, aka the rapid or home test. The test samples are collected the same way for each, but the processing methods are different. Both tests require a swab up the nose, or down the back of the throat, to collect a fluid sample. The PCR test swab is sent to a lab for processing, and the rapid test reveals results within 15-20 minutes, on the spot, similar to a home pregnancy test. Each test has pros and cons which will help seniors and companion caregivers decide which test is right for their circumstances.
The PCR Test:
- When: “The prime time to take a PCR test is when you have had a known or suspected exposure to someone with Covid-19 or are experiencing symptoms, and you want to find out if you have a coronavirus infection,” according to CNN Health.
- Where: PCR tests are administered at doctors’ offices, testing facilities and some pharmacies
- You have been exposed to the virus, and you want to know if you are also infected
- You plan to travel, visit with immunocompromised people, or attend a large event
- How Long: In California, “Turnaround time for COVID-19 test results is usually less than two days. About two-thirds come back within a day, and more than 85% are available within two days.”
- How Much: Free through insurance, free if you’re uninsured, and up to $300 or more for rapid tests depending on where you go and how urgently you need a test
- Pros: This test can detect the smallest amount of virus in the sample which means that infection will be confirmed (“a positive result”) even before symptoms show. The accuracy is nearly 100%
- Cons: Testing the sample requires a lab with skilled technicians and special equipment, so the results can take hours to days to come back
The Rapid Antigen Test:
- When: “[A] rapid antigen test (or rapid lateral flow test) is what you should be taking after you have had Covid-19 for several days and want to confirm you’re probably no longer infectious to other people,” reports CNN Health.
- Where: these tests are sold over the counter and online and shipped for free by USPS. You can take the sample anywhere you’re comfortable using a nasal swab.
- Why: You are sick now, or you were just very sick, and you want to know if you’re still infectious, i.e. can spread the virus to others
- How Long: Results appear within 15-30 minutes, depending on the test brand
- How Much: Free to not cheap, depending on how quickly you need the test, how many are available, and where you buy them. For example, CVS sells four home ‘self-tests’ ranging from $9.99 to $38.99 for one test.
- Pros: Easy to use
- Cons: This test only returns a positive result when it finds TONS of virus in the sample, so early stages of infection can come back negative.
Learn more about your testing options, including locations and appointments, on the Covid19.CA.Gov website.