The advantages, disadvantages, and limitations of the COVID-19 antigen rapid test kit are as follows:

Fast Detection Speed: It can usually yield results within 15 to 30 minutes. Compared with methods such as nucleic acid testing, it enables users to know their infection status more quickly, facilitating the timely adoption of corresponding measures.
Simple Operation: Generally, nasal swabs or pharyngeal swabs are used for sampling, and the operation is relatively straightforward. It does not require professional technicians or complex laboratory equipment. Ordinary people can conduct the test at home by themselves after simple training, which improves the convenience and accessibility of the test.
Low Cost: In terms of both the cost of the reagents and the overall cost of the testing process, it is relatively lower compared to nucleic acid testing. In scenarios such as large-scale screening, it can reduce the testing cost and alleviate the economic burden on society and individuals.
Timely Initial Screening: It can serve as a means of preliminary screening. In epidemic prevention and control, it can quickly screen a large number of people and promptly identify possible infected individuals, which helps to control the spread of the epidemic in the early stages.

Relatively Low Sensitivity: Compared with nucleic acid testing, the sensitivity of antigen testing may be slightly worse. Especially in the early stages of infection when the viral load is low, false negative results may occur, that is, the person is actually infected with the COVID-19 virus, but the test result shows negative, which is likely to lead to missed diagnoses.
Cross-Reactions Exist: It may have cross-reactions with other respiratory viruses, resulting in false positive results. For example, when infected with other coronaviruses that have similar antigens to the COVID-19 virus, it may be misdiagnosed as positive for the COVID-19 virus, and further confirmation by methods such as nucleic acid testing is required.
Limited Test Samples: It mainly conducts tests on samples such as nasal swabs and pharyngeal swabs. The testing effect for some lower respiratory tract samples such as sputum may not be as good as that of nucleic acid testing. Moreover, different sampling sites and sampling qualities may have a significant impact on the test results.

Cannot Replace Nucleic Acid Testing: Due to the limitations of its sensitivity and specificity, antigen testing cannot be used as the sole basis for diagnosing COVID-19 infection. Nucleic acid testing remains the “gold standard” for diagnosis. In key links such as clinical diagnosis and determination of close contacts, nucleic acid testing is usually still relied on to provide more accurate results.
Limited Effectiveness in Detecting Asymptomatic Infected Individuals: For asymptomatic infected individuals or those in the incubation period, the viral load in their bodies may be low, and antigen testing may have difficulty accurately detecting the viral antigen, making it prone to missed detections. It cannot comprehensively and accurately screen out all potential infected individuals.
Time Constrained: Antigen testing can only achieve high accuracy within a specific time period after infection. Generally, the testing effect is relatively good within 5 to 7 days after infection. Beyond this time, as the viral load changes, the accuracy of the test may be affected.