Table of Contents
Introduction
Antigen rapid tests have emerged as a critical tool in the fight against COVID-19. They offer quick and affordable testing solutions compared to RT-PCR tests, which are considered the gold standard. However, questions regarding their accuracy have sparked widespread discussion among healthcare professionals and policymakers.
Accuracy of Antigen Rapid Tests
Antigen rapid tests detect specific proteins from the SARS-CoV-2 virus and provide results typically within 15 to 30 minutes. The accuracy of these tests is primarily measured in terms of sensitivity and specificity.
Sensitivity
Sensitivity refers to a test's ability to correctly identify those with the infection (true positive rate). Studies suggest that the sensitivity of antigen rapid tests can vary significantly, often ranging between 50% to 85%, depending largely on the viral load in the sample and the phase of the infection.
For example, a meta-analysis published in the British Medical Journal reported the pooled sensitivity of antigen rapid tests to be approximately 71.2% (95% Confidence Interval: 63.6%-77.9%).
Specificity
Specificity measures a test's ability to correctly identify those without the infection (true negative rate). Antigen rapid tests generally exhibit high specificity, often reported above 95%. The same meta-analysis indicated a pooled specificity of approximately 98.9% (95% Confidence Interval: 97.3%-99.5%).
Factors Influencing Accuracy
- Sample Quality: The accuracy is highly dependent on the quality of the sample collection, which can be a nasal or throat swab.
- Viral Load: Tests are more accurate during peak viral loads, typically early in the course of the infection.
- Test Brand: Various antigen tests from different manufacturers show variability in performance.
Immuno Company Solutions
Several companies specialize in the production of antigen rapid tests, offering unique solutions to maximize accuracy and accessibility.
Company A
Company A offers antigen rapid tests with a reported sensitivity of 80% and specificity of 98%. Their tests include a digital app for result interpretation, enhancing the ease of use.
Company B
Company B provides an antigen rapid test with innovative dual-function technology, claiming increased sensitivity of 85% and maintaining a high specificity of 99%. They focus on distribution in remote areas to increase accessibility.
Company C
Company C has developed a rapid test kit featuring a unique antigen detection system with an overall sensitivity of 75% and specificity of 98%. The kits are designed for home usage with self-guided instructions.
References
- Peeling RW, et al. British Medical Journal. Systematic review of antigen rapid test sensitivity and specificity. BMJ 2021;372:n395.
- World Health Organization. Antigen-detection in the diagnosis of SARS-CoV-2 infection. Interim guidance. October 6, 2020.
- U.S. Food & Drug Administration. Independent evaluation of antigen tests for screening purposes.