1. The Rapid Coronavirus Antibody Test: Can We Improve Accuracy?
- Author
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Ina P. Pavlova, Sujit S. Nair, Natasha Kyprianou, and Ash K. Tewari
- Subjects
Opinion ,medicine.medical_specialty ,Coronavirus disease 2019 (COVID-19) ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Population ,Asymptomatic ,Internal medicine ,Case fatality rate ,medicine ,neutralizing antibodies ,education ,rapid tests ,lcsh:R5-920 ,education.field_of_study ,SARS-CoV-2 antibodies ,biology ,business.industry ,General Medicine ,lateral flow assays ,paper based analytical devices ,Coronavirus antibody ,Elisa test ,biology.protein ,Medicine ,Antibody ,medicine.symptom ,lcsh:Medicine (General) ,business - Abstract
We are at a critical stage in managing the response to the COVID-19 outbreak, which requires widespread access to fast and accurate testing. While PCR testing has been the backbone for COVID-19 diagnosis, now there is an urgent need for surveillance of at-risk asymptomatic populations. Antibody tests check for an antibody response to SARS-CoV-2 infection and are used to determine infection and case fatality rates, or potential immunity in recovered patients and in vaccine studies. Effective laboratory SARS-CoV-2 antibody technologies have been developed, and some were validated by the FDA to have Sensitivity (Se) and Specificity (Sp) as high as 99–100%1. For example, an IgG two-step ELISA test measures IgG responses to the recombinant receptor binding domain (RBD) of the SARS-CoV-2 spike protein (1). Positive samples are confirmed in a second step that measures IgG response to the whole spike protein (1), resulting in a 100% Sp (with 92.5% Se)1. However, while accurate, laboratory technologies are slow and rely on expensive equipment. Rapid (minutes vs. hours) and instrument-free SARS-CoV-2 assays are commercially available, and some are already being used in surveillance studies. Debates about the recently reported infection rates in NYC (21.1% as of 04/23/202), or in Santa Clara, CA [2.45% (2)], have raised questions regarding whether antibody testing is sufficiently accurate to guide medical or policy decisions. Recently, the COVID-19 Testing Project validated 10 rapid commercial tests in a head-to-head comparison with samples from 80 SARS-CoV-2 RT-PCR-positive, 108 pre-COVID-19 negative, and 52 recently negative patients (3). Many rapid tests performed worse than their manufacturer's specifications, raising questions about their quality and stability. Moreover, while high specificity is crucial for testing low prevalence population (estimated COVID-19 prevalence is only ~5%), only three out of 10 rapid tests had a Sp of >99%, while maintaining >90% Se (at >16 days after onset of symptoms) (3). More recently, the FDA started their own validation of 13 EUA approved antibody tests and found that only one of the validated rapid tests has a > 99% Sp (with a 95% Se)1. Introducing more stringent FDA criteria has driven the need for highly accurate rapid tests3. Here we summarize some of the limitations of rapid COVID-19 antibody tests and suggested ways for improvement.
- Published
- 2020
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