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How Accurate Are Rapid Antigen COVID Tests?

The emergence of COVID-19 virus variants paved the way for the increasing use of rapid antigen testing. 

Rapid antigen tests have become popular to detect COVID-19 because they offer results fast. Aside from helping curb COVID-19 infections, they are convenient to use, give results in minutes and are relatively inexpensive.

But the most anticipated question arises—how accurate are rapid antigen COVID tests?

Before providing the answer to this question, let us work around some facts why rapid tests are crucial against COVID-19 detection.

When Is the Best Time to Get Tested for COVID-19?

If you are exposed to someone with COVID-19, it is imperative to get tested whether you have symptoms or not. This way, it is easier to prevent a large percentage of transmission and infections.

Looking for individuals that are asymptomatic allows the prevention of the virus from spreading. This is essential because asymptomatic infection is a silent spreader of COVID-19. And medical experts made the tests possible to detect asymptomatic patients.

The incubation period of the coronavirus is around 5 to 7 days, yet it can go up to 14 days or more. So, you don’t need to get tested if you have no history of exposure with infected people.

In case you get tested a little early right after exposure, some results would yield a false-negative. Some people have little to zero cultivable virus after 9–10 days despite a positive polymerase chain reaction (PCR). Meaning, an individual had the virus but tested positive long after they were no longer contagious to others. 


Rapid Tests Vs PCR Tests

Generally, there are two types of tests for COVID-19 detection. 

The rapid antigen testing detects a portion of protein. The process of collecting mucus and cells is similar to that of a PCR test. However, this test doesn't require lab visits and waiting times.

Rapid antigen tests contain a test strip in which it reacts with the coronavirus antigens present in your mucus sample. In the rapid test, the strip will change colour in case you are positive. 

On the other hand, the RT-PCR test is molecular-based; it looks for the virus’ genetic material that is in the patient’s mucus and infected cells sample. It is collected by inserting a cotton swab up your nose or swabbing the inside of your cheek. The collected specimen is added to a tube of fluid and is sent to the lab. 

What Is a False Positive Result? False Negative?

Getting a false-negative result means you may be sick or infected but yielded negative results, False-positive, on the other hand, means, results yielded positive but your viral level isn’t enough.

What Does a Faint Line Mean on a Rapid COVID-19 Antigen Test?

A single red line beside the control marker C on the test kit suggests a negative result. If there is a second line next to the marker T, it indicates a positive result. Even a faint second line would suggest your test is positive.

Regardless if the lines are faint or smudged, they are still valid and should be turned in. 


Where Can I Get Rapid Antigen COVID Tests?

The result from a rapid antigen test for COVID-19 does not need to be checked in a laboratory. It can also give you results within minutes.

A rapid antigen test or point-of-care test can be done at the following: 

  • Pharmacies
  • School clinics
  • At home 
  • At the doctor’s clinic
  • Airports
  • Long-term facilities 
  • Drive-through testing locations

A medical professional (or yourself) inserts a cotton swab inside your throat, nose or both to collect cells and mucus samples. The sample is applied to a strip that can change colour if you are positive for coronavirus. 


How Accurate Are Rapid Antigen COVID-19 Tests?

Rapid antigen testings are not as accurate compared to laboratory tests because they need more virus level in your sample for it to be reported as positive. This type of test has a higher risk of showing a false-negative result. This means that the test can indicate that you don’t have the virus when, in fact, you have it. 

1. If You Have COVID-19 Symptoms?

If you are showing COVID-19 symptoms, rapid antigen tests can give correct positive results around 72% of the time. The 95% intervals of confidence fall between 64% to 80%. This means experts are 95% confident that the average level falls under these values. 

2. If You Don't Have Symptoms?

Researchers figured out that if you don’t have coronavirus symptoms, you will get a positive result in about 60%. 

3. In the First Week of Symptoms?

You will get accurate positive test results for COVID-19 when given during the first week of your symptoms. Rapid tests can correctly identify COVID-19 in an average of 74% of cases, and this is during the first earliest week. There is a significant drop to 51% in the second week. 

4. Why Use It If It’s Less Accurate?

Rapid antigen tests for COVID-19 provide numerous advantages over PCR tests amidst the high probability of getting a false-negative result. 

  • Inexpensive options compared to lab tests
  • Can give results in minutes 
  • More accessible and convenient 
  • No lab specialist needed 


Several locations provide rapid COVID-19 testing, such as airports, theme parks, arenas and other crowded places, to screen for positive cases. Rapid antigen tests may not be the most accurate to detect the coronavirus, yet they can catch some cases that may have gone undetected. 


Dexcon | Leading Medical PPE Supplier in Australia


The pandemic is not totally over yet. Our vigilance to health and safety protocols is being called for to save or heal us from the virus. In this light, rapid antigen tests serve as a promising tool to help fight COVID, vaccinated or not. Personal discrepancy in good hygiene and obeying health protocols is an ultimate protection you can give to yourself.

If you are looking for rapid antigen tests to serve their purpose, Dexcon, a trusted rapid antigen test kit provider in Australia has your back. We are your partner in getting quality test kits. For more information on our PPE and medical device solutions, give us a call on 1300 847 000.


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