COVID-19 rapid antigen tests assays are intended to rapidly diagnose active infection by identifying a SARS-CoV-2 viral protein antigen (the virus that causes COVID-19.)

Self-administered rapid antigen tests are performed at home using a simple shallow nose swab. Rapid antigen tests take around 15 minutes to complete after specimen collection.

When there is a greater likelihood that you have COVID-19, testing is most accurate (e.g. you live in an area with high number of cases, are showing symptoms, etc.). Additionally, antigen tests are more likely to identify a genuine positive early in the course of illness, when the virus is more prevalent in your system. Rapid antigen tests are often less sensitive than molecular tests, which leads to the possibility of false-negative test findings. That is why DPH has supplied these advices for the next steps you should take in light of your test result.

Who Is a Candidate for an Antigen Test?

• Individuals who have COVID-19-related symptoms, particularly within seven days of symptom onset. Please refrain from visiting the library to receive a test if you are experiencing symptoms.

• Close contact with someone who has been diagnosed with or suspected of having COVID-19 but is asymptomatic. Take the test immediately upon discovering you are in close touch. If the test is negative, repeat it 5-7 days after your last encounter with the COVID-19 carrier — or soon if symptoms arise.

o Close contacts who are symptom-free AND completely vaccinated against COVID-19 are not need to be tested or quarantined after close contact exposure (exceptions for certain groups of fully vaccinated people to continue testing).

• Individuals who exhibit no symptoms yet engage in higher-risk activities and are unable to physically separate themselves as required (e.g., travel, attending large social or mass gatherings, or being in crowded indoor settings). Click here to learn some insight advice on rapid antigen tests.

• Individuals who exhibit no symptoms yet are anxious and need a prompt response (ie: before going to visit an immunocompromised family). This illness screening may aid in the early discovery of COVID-19, allowing for urgent public health action.

• Individuals with no symptoms who routinely employ antigen testing to identify suspected asymptomatic illness.

Many of us, in particular, are seeking for simpler and quicker methods to determine if we are virus-free. And doing an at-home COVID test seems to be an extremely practical option — particularly given that some provide speedy results.

Which COVID at-home test is the best?

To begin, verify that the at-home COVID-19 rapid antigen tests you’re contemplating are FDA-approved.

Following that, it’s time to evaluate the two classifications:

• Polymerase chain reaction (PCR) test — you take a sample at home and ship it to a laboratory for analysis.

Rapid antigen tests – you take a sample at home, test it with the kit materials provided, and get a result in minutes.

Which of the two is the better fit for you? It varies, and the correct answer may be both.

“Whether or not you have symptoms, a PCR test is always the most reliable and sensitive method of viral detection. Typically, the results of an at-home PCR test take a few days to arrive “Dr. Long asserts.

By contrast, rapid antigen tests provide immediate findings. However, Dr. Long advises that antigen testing is most effective early in the course of the illness if symptoms are present. If the test is negative, the findings should be validated using a polymerase chain reaction (PCR). This information is included in the package insert for the majority of rapid antigen tests.

“If you’ve had a known exposure and are exhibiting symptoms, a fast antigen test may be a useful tool for swiftly confirming that you’re positive for COVID-19,” Dr. Long explains.

Rapid antigen tests are not without limitations. False positives are possible with rapid antigen tests, but they are less probable if you are symptomatic.” What is more problematic, though, is a false negative. This occurs when your test results are negative despite the fact that you are infected with COVID-19. Because false negatives are very prevalent with rapid antigen tests, it is critical to confirm a negative antigen test with a PCR test — which is far more reliable and sensitive “Dr. Long adds.

Finally, keep in mind that PCR test results may not usually take a few days.

“At Houston Methodist, we provide rapid turnaround on PCR testing. While samples are collected at our sites rather than at your residence, we often turn over findings in less than 24 hours “Dr. Long continues.

If you are experiencing symptoms or have been exposed to COVID-19 and are interested in a PCR test at Houston Methodist, schedule an appointment with one of our Virtual Urgent Care doctors.

Can fast COVID testing performed at home really make a gathering safer?

In an ideal pandemic environment, you might attempt to schedule a “safer” meeting by doing at-home rapid antigen testing to ensure that neither you nor your visitors are infected with COVID-19.

Regrettably, these rapid antigen tests are not sensitive enough to ensure the safety of a meeting. Additionally, they may provide a false feeling of security.

Rapid antigen tests often overlook infection that is asymptomatic. Indeed, they are more likely to be false negative during that time period, and several are licensed for use only in patients who exhibit symptoms. I would caution against using at-home fast antigen testing to screen for COVID before to a gathering, particularly given that a person may spread the virus while asymptomatic “Dr. Long notes.

And if you develop symptoms before a gathering, an at-home fast antigen test may establish that you are COVID positive — but did you really need a test to realize that it is probably advisable to take a rain check and get a PCR COVID-19 test instead?

At-home testing does not replace immunization, masking, or social isolation.

Whether you’re planning a safe gathering, considering how to remain safe at work, or just want to take a chance at that crowded indoor event, bear in mind that at-home COVID testing does not replace the preventative measures that have been shown to keep us safe throughout this epidemic.

The most effective strategy to prevent the transmission of COVID-19 is to: 

  • Vaccinate 
  • Test for COVID-19 symptoms 
  • Wear a mask 
  • Maintain social distance 
  • Avoid poorly ventilated interior places 
  • Avoid crowds