Testing for COVID is vital to helping reduce the spread of the SARS-CoV-2 virus.
Whether you’re experiencing symptoms, were exposed to someone with confirmed COVID, are following workplace guidelines, or taking precautions before traveling or visiting immunocompromised friends and loved ones, COVID tests remain an important public health resource.
Both vaccinated and unvaccinated individuals can get tested for COVID-19.
Importantly, there are different types of COVID-19 tests, each with their own specific advantages, disadvantages, and use-cases.
Rapid testing is a popular option for at-home or self-testing.
Demand for rapid testing has increased of late, due to its convenience and fast turnaround time.
However, there are some instances in which you may want to confirm a rapid test result with a lab or PCR test (also called a nucleic acid antigen test, or NAAT).
In this article, I’ll describe how rapid COVID tests work and when and how you can use them.
I’ll also cover the latest recommendations from the CDC on what to do if you test positive with a rapid COVID test.
What are Rapid COVID Tests?
Rapid COVID tests, also called self-tests, rapid antigen, or at-home rapid tests, are easy-to-use tests that screen for the COVID-19 virus.
The biggest advantage of rapid COVID tests is the turnaround time—unlike lab tests that require a 24-72 day turnaround for results, rapid tests deliver results within 15 minutes.
How Do Rapid COVID Tests Work?
Rapid COVID tests are a type of diagnostic test designed to determine whether or not you are infected with the COVID virus.
These tests work by looking for a specific protein that lives on the outer surface of the virus.
By contrast, molecular tests like laboratory-performed PCR tests instead look for the general presence of COVID viral material.
Though rapid tests can deliver results faster than lab tests, they aren’t as sensitive as lab tests and have a higher chance of missing an active infection.
When viral levels are low (which can happen at the beginning of an infection or if someone is asymptomatic), some rapid at-home tests may produce a false negative result.
For that reason, if you take a rapid test and get a negative result, your provider may recommend taking a confirmatory PCR test—especially if you’ve had known exposure to someone with confirmed COVID.
Alternative to At-Home Rapid Tests
In addition to at-home rapid tests, some companies offer at-home NAAT or PCR tests.
In these cases, you collect the sample (either nasal or saliva) from the comfort of your home either by following written instructions or with the guidance of a healthcare provider over a video call.
Then, you package the sample as directed and ship it back to the lab (often with next-day shipping).
Like other laboratory-based testing, turnaround time for receiving your results is generally between 2-3 days.
Though the turnaround time is longer than at-home rapid testing, there are some advantages of at-home laboratory-based testing:
- Higher accuracy and sensitivity than rapid tests
- You don’t have to travel to a clinic or pharmacy to collect your sample
Some employers may offer at-home NAAT testing for free to their employees, so it’s a good idea to ask your HR representative if this is an option for you.
Otherwise, keep in mind that these tests are more expensive than rapid antigen tests and could cost you around $100 per test.
Some companies and labs that offer this test include:
- Vault Health
- Quest Diagnostics
When Should You Take a Rapid Test?
There are several instances in which you might want to take an at-home rapid COVID test, including:
- When you’re experiencing symptoms of COVID-19 (even after vaccination)
- When you’ve had known exposure to someone with confirmed COVID-19
- Before gathering with immunocompromised loved ones
- If you’re complying with local or employer mandates
Above all, taking an at-home rapid test is a good idea if you cannot wait 2-3 days for the turnaround of a lab test or if you cannot find an appointment for a lab test.
Are At-Home Rapid COVID Tests Accurate?
Although rapid tests aren’t as sensitive as nucleic acid-based laboratory-performed tests, many still provide accurate results.
However, the accuracy is largely dependent on how the test is done (for example, if the swabbing is thorough enough), and if the person has symptoms.
Using the data from manufacturers, many at-home rapid tests indicate the same result as corresponding PCR tests over 80% of the time.
However, it’s important to note that real-world accuracy rates might not be as high.
Still, the vast majority of rapid tests reviewed in this systematic review and meta-analysis were able to detect COVID in the first week of symptom onset in those with a high viral load.
But another study found that two popular at-home testing options (QuickVue and BinaxNOW) may not be reliable at detecting cases of Omicron in the first few days of infection.
Ultimately, neither at-home nor laboratory-based tests are 100% accurate.
But rapid tests remain an important resource when access to laboratory-based tests are limited and immediate results can help to screen for and limit the spread of the virus.
How to Take an At-Home Rapid COVID Test?
Rapid at-home COVID tests are designed to be easy-to-use.
Regardless of which test you purchase, each one will come with a step-by-step instruction guide for you to follow.
Generally, test directions may ask you to:
- Wash your hands thoroughly before opening the test materials
- Use a clean and disinfected surface on which to lay out the test materials
- Using the same swab, collect a sample from the inside of each nostril for a designated time (usually between 10-15 seconds)
- Insert the swab into a vial or component of the test
- Wait a specific amount of time before reading the results of the test
Whether it’s your first or fourth time taking an at-home rapid test, it’s important to follow the instructions carefully, as some steps may vary depending on the test manufacturer.
Additionally, it’s important to wait the exact amount of time designated before reading your test results.
Some test results won’t be valid until that time is reached, while others may become invalid if you wait too long before interpreting the results.
Should You Swab Your Nose or Throat?
Most at-home rapid tests require a swab of your nose (collected via each nostril) and it’s important to follow the test’s instructions for sample collection carefully.
While some people have suggested that adding a throat swab to your at-home nasal-based test may increase the likelihood that the test can detect cases of Omicron, experts from the FDA caution against experimenting with at-home tests that were developed only using nasal swabs.
Put simply, if the test doesn’t specify taking a throat swab, don’t take one. When in doubt, follow the test instructions to the letter.
Where to Find At-Home Rapid COVID Tests?
At-home COVID tests do not require a prescription or provider’s note and can be purchased online or at a brick-and-mortar pharmacy.
When buying online, be sure to confirm the manufacturer is reputable and whether or not the test has received emergency use authorization (EUA) from the FDA.
Here are some manufacturers who make at-home rapid COVID tests:
- BD Veritor (BD)
- BinaxNOW (Abbott)
- CareStart (Access Bio)
- Celltrion DiaTrust (Celltrion)
- Clinitest (Siemens)
- SD Biosensor
- Flowflex (ACON)
- InteliSwab (Orasure)
- On/Go (Intrivo)
- QuickVue (Quidel)
- Lucira CHECK-IT (Lucira)
What to do If You Test Positive
If you test positive after taking an at-home rapid test, the CDC recommends that you:
- Inform your healthcare provider as well as any close contacts you spent time with in the 48 hours before you started experiencing symptoms or tested positive.
- Stay home and isolate for at least 5 days. Be sure to rest and drink plenty of fluids during that period.
- If you are asymptomatic or if symptoms resolve during the 5 day isolation, you can end your isolation period but continue wearing a well-fitted mask around others for another 5 days to limit spread of the virus. If you continue to be symptomatic after 5 days, continue to stay home and isolate until you feel better.
In most cases, vaccinated and otherwise healthy people are likely to experience a mild case of the virus.
However, if you’re unvaccinated or immunocompromised you may experience more severe symptoms.
If you experience any of the following symptoms after a positive COVID test result, seek urgent care immediately:
- Trouble breathing
- Persistent chest pain and/or pressure
- New confusion
- Inability to wake or stay awake
- Pale, gray, or blue-colored skin (depending on skin tone)
The Bottom Line
If you’re experiencing symptoms or looking for an easy-to-use diagnostic COVID tool, rapid tests are a convenient way to help you stay informed of your viral status.
If you’re unsure whether or not an at-home or PCR test is best for your circumstances, reach out to your provider for more information.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.
K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references.
Accuracy of novel antigen rapid diagnostics for SARS-CoV-2: A living systematic review and meta-analysis. (2021)
CDC Updates and Shortens Recommended Isolation and Quarantine Period for General Population. (2021).
Coronavirus Disease 2019 Testing Basics. (2021)
COVID-19 Testing: What You Need to Know. (2021)
Discordant SARS-CoV-2 PCR and Rapid Antigen Test Results When Infectious: A December 2021 Occupational Case Series. (2022).
Over the Counter At-Home Tests for COVID-19 from The Medical Letter. (2022)
Should you add a throat swab to your at-home covid test? Experts disagree. (2022)
Your Questions About Home COVID-19 Tests, Answered. (2021)