The Ultimate Guide to COVID-19 and Flu A/B Rapid Antigen Tests

Naheed Ali, MD, PhD

COVID-19 is a highly contagious respiratory disease that has been on the rise since early 2020. Cumulatively, as of February 16, 2023, 756,291,327 COVID-19 confirmed cases with 6,841,640 deaths had been reported to the World Health Organization (WHO). The Australian government's Department of Health and Aged Care surveillance reports concerning the influenza virus are slightly worse than expected.

Because of this, we must take every precaution to protect ourselves and our loved ones from the virus. One way to do this is by getting tested for both COVID-19 and the flu A/B rapid antigen test. This article will walk you through what you need to know about these tests, including what they are and why they're essential.

What Is the Difference Between Flu and COVID-19?

The flu and COVID-19 are both respiratory illnesses caused by different viruses. The flu is caused by the influenza viruses (A and B), while SARS-CoV-2 causes COVID-19. Another key difference is the way the virus spreads. The flu primarily spreads through respiratory droplets from coughing or sneezing, while COVID-19 can also be spread by touching contaminated surfaces and objects. Treatment for the flu and COVID-19 can also differ. The flu can be treated with antiviral medications, but there is no specific treatment for COVID-19. Instead, treatment for COVID-19 focuses on managing symptoms and preventing complications.

Common Symptoms of Flu and COVID

1.Flu Symptom

Flu symptoms include fever, chills, a runny nose, a sore throat, fatigue, and muscle aches; some people also have vomiting and diarrhea. The flu virus can spread quickly through the air when an infected person coughs or sneezes. Symptoms may appear 5-7 days before the infected individual becomes contagious. Children can spread the virus for up to seven days after becoming ill.

2.COVID-19 Symptoms

COVID-19 is characterized by fever, cough, fatigue, and loss of taste and smell. The severity of this viral disease varies from person to person. In most cases, people who get infected will develop a mild to moderate illness and recover without hospitalization. However, the symptoms of this disease are similar to those of the flu, but in many cases, they can be much more severe. These include difficulty breathing, shortness of breath, loss of speech or mobility, confusion, and chest pain. Therefore, seek immediate medical attention if you have severe symptoms. However, if you are otherwise healthy, you can manage mild symptoms at home. COVID-19 symptoms usually appear 5–6 days after infecting someone with the virus, but it can sometimes take up to 14 days.

What Are COVID-19 and Flu A/B Rapid Antigen Tests?

The COVID-19 and flu A/B rapid antigen tests are used to quickly diagnose the presence of the viruses that cause COVID-19 and influenza (flu). These tests typically provide results within 15–20 minutes and are often used in settings where a quick diagnosis is needed, such as hospitals, clinics, and testing sites.

It works by detecting specific proteins (i.e., antigens) on the surface of the viruses. A sample of a patient’s nasal or throat swab is placed on a test strip and mixed with a solution that contains antibodies that can bind to the viral antigens. Suppose the viruses are present in the sample. In that case, the antibodies will bind to the antigens and produce a visible result, such as a line or a color change, indicating a positive test result.

What Are the Advantages of Using COVID-19 and Flu A/B Rapid Antigen Tests?

The rapid antigen test is a point-of-care test that allows healthcare professionals to quickly and accurately diagnose COVID-19 and influenza. The following are the advantages of using rapid antigen tests:

1. Quick Test Results

Rapid antigen tests can provide results within minutes, making them a valuable tool for identifying and controlling the spread of infectious diseases. The antigen test takes more than 15–20 minutes to complete, which means that you'll get your results faster than ever before.

2. Easy On Patients

Rapid antigen tests don't require special preparations like blood draws or other invasive procedures. They're quick and easy to perform, which means healthcare providers won't put any extra stress on patients who might already be feeling weak or ill.

3. Cost Effective

The test kits can be purchased online or at local pharmacies and they provide peace of mind by allowing you to take control of your health. You will not have to go through long waiting periods before receiving your results, which helps save time and money.

How Can COVID-19 and Flu A/B Rapid Antigen Test Help in the Early Stages of Symptoms to Stop the Spread of the Virus?

Rapid antigen tests can help identify the presence of a virus, such as the flu or COVID-19, in the early stages of infection. It can help stop the spread of the virus by allowing individuals who have been infected to self-isolate and seek medical treatment, while also allowing public health officials to trace and monitor the spread of the virus.

How Are COVID-19 and Flu A/B Rapid Antigen Test Samples Collected? 

Rapid antigen tests are usually collected using a nasal or throat swab. The patient being tested will insert the swab into their nose or throat according to the instructions provided with the test kit. The swab is then placed in a solution, and the resulting sample is analyzed to determine if he has a current infection with the virus that the test is designed to detect. It's essential to follow the instructions provided with the test kit carefully to ensure that the sample is collected correctly and that the test results are accurate.

When Should I Get the COVID-19 and Flu A/B Rapid Antigen Test?

It is typically recommended for people who are experiencing symptoms of COVID-19 or the flu, such as fever, cough, and difficulty breathing. This test can help determine if someone is infected with the virus and needs to isolate and seek medical treatment.

Importance of Sensitivity

Sensitivity is an important factor to consider when choosing a flu or COVID-19 rapid antigen test. Sensitivity refers to the ability of a test to correctly identify individuals who have the virus. A highly sensitive test will correctly identify most individuals who have the virus, while a less sensitive test may miss some cases.

This is especially important for medical disorders like COVID-19 and flu, where early diagnosis and prompt treatment can be critical for reducing the severity of the illness and preventing transmission to others. A rapid antigen test with low sensitivity may result in false negative results, meaning that individuals who have the virus may be incorrectly told that they do not have it. This could lead to individuals not seeking the necessary treatment and potentially spreading the virus to others.

On the other hand, a test with a strong sensitivity level will correctly identify most cases of the virus, allowing individuals to get the necessary treatment and helping to prevent the spread of the virus. For this reason, it is important to choose a rapid antigen test with high sensitivity when testing for COVID-19 or flu.

When Should the COVID-19 and Flu A/B  Rapid Antigen Test Not Be Used?

These tests are most effective in people who have symptoms of COVID-19 or the flu and have been exposed to the virus. If you have been exposed to the virus but do not have symptoms, a rapid antigen test may not be able to detect the infection.

 ğIn addition, rapid antigen tests may not be practical in people with a weakened immune system or taking certain medications that can suppress the immune system. It is always best to consult a healthcare provider to determine the most appropriate testing method for your situation.

What if My COVID-19 and Flu A/B Rapid Antigen Test Results Are Positive?

If your COVID-19 and flu A/B rapid antigen tests are positive, it means that you have tested positive for either COVID-19 or the flu. In this case, you are contagious and should take precautionary measures to avoid spreading the infection.

Why Are the COVID-19 and Flu A/B Combo Rapid Antigen Tests Ideal?

The COVID-19 and Flu A/B Combo Rapid Antigen Tests are ideal for several reasons:

  1. They can provide fast results, which is essential for quickly identifying cases and taking appropriate action.

  2. They are highly accurate and vital for ensuring that individuals receive the proper care and treatment.

  3. They are relatively easy to perform, which makes them a good option for a wide range of settings, including hospitals, clinics, and other healthcare facilities.


Rapid antigen tests are a new tool for diagnosing viral infections like COVID-19 and the flu. Rapid antigen self-testing kits have made it possible for individuals to quickly and conveniently test themselves for the presence of specific viruses from the comfort of their own homes. This test can provide individuals with quick and accessible information about their health and help to prevent the spread of infectious diseases.

With the TouchBio® COVID-19 and Flu A/B Rapid Antigen Combo Test, SARS-CoV-2 and influenza A and B antigens can be instantly detected in a single nasal swab specimen, and accurate results can be obtained within 15 to 20 minutes. It has a very high sensitivity, with a specificity of more than 98%.

About the Author

Dr. Naheed Ali is a medical journalist and contributor for TouchBio.


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Australian Government Department of Health and Aged Care. Influenza surveillance program. Australian Government Department of Health and Aged Care. Published November 15, 2022. Accessed December 8, 2022.

Boktor SW, Hafner JW. Influenza. In: StatPearls. Treasure Island (FL): StatPearls Publishing; July 18, 2022.

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