Can other viruses affect antigen testing?
Dec 12, 2025
Source: Cainiu Health
Dr. Li Feng
Introduction
In general, whether other viruses affect antigen testing depends on the specific target of the test. For antigen tests targeting a particular virus, most other viruses do not interfere with the results, although there may be rare exceptions. To ensure testing accuracy, it is recommended to follow the instructions for proper sample collection and avoid sample contamination. Before testing, confirm that the reagents are within their expiration date and have been stored under appropriate conditions.
Generally, whether other viruses affect antigen testing depends on the target of the test. For antigen tests designed to detect specific viruses, most other viruses do not interfere with results; only in rare, exceptional cases might there be an impact. A detailed analysis is as follows:
Antigen tests are highly specific and typically designed to detect particular antigens unique to the target virus. For example, a SARS-CoV-2 antigen test specifically identifies the spike protein of the novel coronavirus. Other viruses such as influenza or the common cold have different antigen structures and therefore will not bind to the test reagents, meaning they do not interfere with the test result.
Only when another virus shares highly similar antigen structures with the target virus, or when the sample is severely contaminated, could false-positive or false-negative results potentially occur. However, such cases are extremely rare and not representative of typical outcomes, so there is no need for excessive concern.
To ensure testing accuracy, it is recommended to follow instructions carefully during sample collection and avoid sample contamination. Before testing, confirm that the test kit is within its expiration date and has been stored under appropriate conditions. If the test result does not match clinical symptoms, consider repeating the test with a different kit or using an alternative testing method.
