- The Food and Drug Administration has authorized emergency use of a coronavirus antibody test from Roche, which said Sunday it plans to produce "high double-digit millions" of the kits this month.
- A study of 5,272 samples run by Roche found the Elecsys test has a specificity of 99.8%, indicating a low likelihood of false positives, and a sensitivity of 100%, suggesting even better performance in avoiding false negatives, when used on samples taken 14 days after confirmed SARS-CoV-2 infection.
- In a bid to improve accuracy of available serology tests for the coronavirus, the FDA on Monday said it's changing how serology test developers submit EUAs and when validation data is required. The agency also outlined particular performance threshold recommendations for specificity and sensitivity for all developers of the serology tests.
In April, Cellex became the first organization to receive an EUA for an anti-SARS-CoV-2 antibody test. By the end of the month, nine other organizations had secured EUAs for antibody tests. Offerings from Abbott and Bio-Rad Laboratories are reported to have specificity levels of just shy of 100%. In addition to Roche's EUA issued in May, FDA posted one for Euroimmun on Monday.
Other companies and labs brought antibody tests to market without first receiving emergency use authorization, due to leniency outlined in FDA's diagnostic policy for the coronavirus public health emergency. That move resulted in a proliferation of tests designed to detect evidence of an immune response against an earlier infection with SARS-CoV-2.
The accuracy of those tests is a concern, especially as state government officials may rely on immunity data as they make plans to reopen their economies.
One recent study out of the University of California, San Francisco, of 12 different tests found the specificity of some tests is as low as 84%. Public health officials have since tried to regain greater oversight over quality of these tests. On April 28, the FDA issued a new umbrella letter of authorization for serology IVDs validated by the National Institutes of Health, National Cancer Institute, or another government agency designated by the FDA.
FDA officials in a blog post Monday said that commercial manufacturers will have to submit EUA requests with validation data within 10 business days from when they notified the agency of their validation testing, or from the May 4 revisions to the policy — whichever is later.
Roche assessed the specificity of its test by analyzing 5,272 samples, most of which came from routine diagnostic testing. Roche's test detected anti-SARS-CoV-2 antibodies in 10 of the samples, resulting in a specificity of 99.81%. A study of 204 samples from 69 patients with SARS-CoV-2 infections found the test was 100% accurate 14 days after diagnosis, suggesting a zero-to-negligible rate of false negatives.
The figures match or exceed those generated on other tests. Roche has also studied its test more widely than some of its competitors. Abbott and Bio-Rad, for example, assessed the specificity of their tests by using them to analyze 1,070 and 687 negative samples, respectively.
At the same time, there remain doubts about whether the presence of antibodies means a person has immunity against SARS-CoV-2 given the early stages of the research into the virus.