Even as more people become fully vaccinated against COVID-19, testing is still a crucial measure in curbing the spread of SARS-CoV-2, the novel coronavirus.
"Testing is important for us to be able to have public health measures to prevent people from being infected in the first place," says Lisa McFarlane, PhD, director of laboratory services at Atlantic Health System in New Jersey.
Why? Because an estimated one-third of people with COVID-19 don't show any symptoms, according to a January 2021 review in Annals of Internal Medicine.
"We need to be able to identify those people and have measures in place to prevent them from infecting others," McFarlane says.
That's not to say you should necessarily run out and get swabbed every single day. Rather, follow these guidelines for situations that warrant a COVID test.
Get tips on how to stay healthy, safe and sane during the novel coronavirus pandemic.
1. You Have Symptoms
If you have COVID-19 symptoms — which include fever, cough, shortness of breath or loss of taste and smell — your doctor might recommend getting tested, per the Mayo Clinic, regardless of your vaccination status, according to the CDC.
Reach out to your health care provider before getting tested if you suspect you have COVID-19, per Johns Hopkins Medicine. If your symptoms are mild, your doc may tell you to hold off. And, if you do get tested, you'll want to be particularly cautious to avoid spreading the infection.
But being symptomatic is not the only reason to get a COVID-19 test. If you live in an area where tests are available, here are other scenarios when it's appropriate — even necessary — to get tested.
2. You Work in a High-Risk Profession
This might include health care or a nursing-home setting.
"If you're working in a situation where you do have high contact with sick patients, it's also imperative to be tested somewhat frequently," McFarlane says.
People who work in health care are considered a high priority because they come in contact with vulnerable populations, per the CDC.
3. You Want to See a High-Risk Relative or Friend
"If they're infected, it could cause the infection to spiral out of control," McFarlane says. You should also get tested if you're a caregiver for someone at high risk, she adds.
Given that tests are only so accurate, you should also monitor for signs and symptoms, says Ravina Kullar, PharmD, a spokesperson for the Infectious Diseases Society of America. Symptoms show up an average of about five days after exposure to the virus, with most patients seeing symptoms within 12 days, per a July 2020 article in the Journal of the American Medical Association (JAMA).
4. You Have Surgery or a Medical Procedure Scheduled
This might actually be out of your hands. Many facilities are requiring COVID-19 tests before a procedure or surgery, Kullar says. Once you have a negative result, then you can go in. The Anesthesia Patient Safety Foundation recommends that all patients have a SARS-CoV-2 test before non-emergency surgery.
Atlantic Health System, where McFarlane works, requires patients to be tested before procedures.
"We went from testing symptomatic patients who came into institutions or doctors' offices to now broad-based testing of everybody," she explains. "And certainly from the hospital perspective we do try to protect patients and employees as well."
5. You're Unvaccinated and Had Direct Contact With Someone Positive or Symptomatic
SARS-CoV-2 travels with extreme speed and efficiency. "If you've been in contact with someone who has actually tested positive, absolutely, absolutely, yes, you should seek out a test," McFarlane says.
If you're fully vaccinated and do not display any COVID-19 symptoms, you no longer need to be tested after exposure to someone who is sick, according to the CDC.
Similarly, if you tested positive for COVID-19 within the past 3 months and have recovered, you don't need to get tested after coming in contact with someone with symptoms, per the CDC, as long as you don't have any symptoms.
Don't Get Tested Too Early
If you test too early after you think you’ve been exposed to COVID-19, you may get a false negative result, McFarlane says. (That is, the test result will be negative, when in fact, you have the virus.) The chances of having a false negative are higher the closer you are to the infection date, according to an August 2020 study in Annals of Internal Medicine.
“In most people the viral load is increased within reason somewhere between three to five days after infection,” McFarlane says, so wait a few days before getting tested.
6. You're Unvaccinated and Have Been in a Crowd
Fully vaccinated people can begin to return to some more populated indoor and outdoor activities, according to the CDC, but it's still important for unvaccinated people to steer clear of crowds and wear masks if crowds are unavoidable.
After being somewhere you couldn't physically distance yourself to avoid potential COVID-19 exposure, the CDC still recommends testing — regardless of whether you know of anyone else in the group who develops COVID-19.
"You likely don't know everybody in that crowd, and you don't know what their practices are," Kullar says.
As many as half of all transmissions may be through people who have no symptoms, per a June 2020 model in the Proceedings of the National Academy of Sciences.
What to Do While You Wait for Test Results
Shelter in place. While you're waiting, "you should be isolating and quarantining yourself," says Matthew G. Heinz, MD, a hospitalist in Tucson, Arizona. You also shouldn't be visiting with high-risk folks, even if it's just to deliver a meal, he adds. And it definitely means avoiding crowds.
"The test is only as good as your behavior," McFarlane says. "If you've taken a test today and you still are going to high-risk environments, you do run the risk of actually being infected after. Therefore, the results would not be an indication of your current status."
Types of COVID-19 Tests
The gold standard for detecting potential active infections of COVID-19 is the reverse transcription-polymerase chain reaction (PCR) test, Kullar says.
PCR tests vary slightly, but all involve nasopharyngeal swabs, which means getting a sample from the area inside your nose and the back of your throat, according to Johns Hopkins Medicine.
Some collect samples from deep inside your nose. "That's the most accurate," Kullar says. It's also the most uncomfortable since the swab makes a deep dive. Fortunately, it only lasts a couple of seconds.
The "mid-turbinal swab" doesn't penetrate as far but may not be as accurate, McFarlane says. There are also new antigen tests to diagnose COVID-19, according to the U.S. Food and Drug Administration. The tests look for proteins on the surface of the virus, but these antigen tests are not widely used.
Test Results Are Only as Good as the Sample
“Sample collection is key to the performance of the test providing the health care provider is appropriately trained,” McFarlane says.
Look for a site that has a trained health care provider taking the sample.
Many drive-through testing sites require you to take your own sample, which could be iffy, Kullar says.
“You’re likely not going to give yourself a deep swab,” she adds. The same goes for at-home test kits. All samples go to a lab for results. There are approved rapid result tests, but they aren’t widely available, and it’s not clear how accurate they are, Kullar says.
What About Antibody Tests?
Antibody tests are different from PCR diagnostic tests for SARS-CoV-2, per the CDC, and are not used for diagnosing COVID-19.
Antibodies are produced when your body mounts an antibody response to an infection. That means antibody tests tell you if you have had COVID-19 in the past, but not if you have a current infection, per the CDC. Antibodies can take one to three weeks to develop after you've been infected.
What to Expect During a COVID-19 Test
Some testing sites, including Johns Hopkins Medicine, require appointments. Drive-through testing or pharmacy testing sites may not.
COVID-19 tests are available for free at certain locations, per the U.S. Department of Health and Human Services (HHS). That applies to people who have insurance and those who do not. If you do have insurance, it's a good idea to call your insurance company before you get the test to find out the cost, as prices can vary widely.
Where to Get Tested
See state-by-state information on where free COVID-19 tests are available, courtesy of the HHS.
The person taking the sample should be wearing multiple layers of safety gear, such as protective clothing, a mask, a face shield and gloves. You'll likely be asked to follow appropriate social distancing recommendations and wear a mask before and after the actual test.
During the test itself, swabs will be used to take samples from the back of your throat and inside your nose. No, this isn't a comfortable experience, but fortunately, the test is quite brief — it'll be over in mere seconds, per Johns Hopkins Medicine.
Concerned About COVID-19?
Read more stories to help you navigate the novel coronavirus pandemic:
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- Centers for Disease Control and Prevention: “Overview of Testing for SARS-CoV-2”
- Annals of Internal Medicine: “Variation in False-Negative Rate of Reverse Transcriptase Polymerase Chain Reaction–Based SARS-CoV-2 Tests by Time Since Exposure”
- Journal of the American Medical Association: “What Is COVID-19?”
- Proceedings of the National Academy of Sciences: “The implications of silent transmission for the control of COVID-19 outbreaks”
- Anesthesia Patient Safety Foundation: “Preoperative COVID Testing: Examples From Around the U.S.”
- Johns Hopkins Medicine: “Coronavirus Test FAQs”
- Food and Drug Administration: “Coronavirus Testing Basics”
- Centers for Disease Control and Prevention: “Test for Past Infection (Antibody Test).”
- Centers for Disease Control and Prevention: "Interim Guidance on Testing Healthcare Personnel for SARS-CoV-2"
- U.S. Department of Health and Human Services: "Community-Based Testing Sites for COVID-19"
- Mayo Clinic: "COVID-19 diagnostic testing"
- American Medical Association: "AMA statement on CDC changes to COVID-19 testing guidance"
- Annals of Internal Medicine: "The Proportion of SARS-CoV-2 Infections That Are Asymptomatic"