A: The FDA has granted emergency authorization to pharmaceutical company Roche for a new antibody test that is much more accurate than existing options.
Quick reminder about antibody testing: It provides information about PAST (as opposed to current) infections.
Reason for optimism: The new test has much (!) better accuracy than others on the market, with a 1 in 500 false positive rate.
In comparing the performance of the new test with the first antibody test receiving FDA emergency auth (Cellex), this Quartz article helpfully explains: “If 5% of 1,000 people have had coronavirus then, using the Cellex test, a positive result stands only 49.5% chance of being correct. Using the Roche test on that same population means that a positive result is 96% likely to be correct.”
Reasons for caution: While its accuracy is now best-in-class, the Roche test is not perfect (as is the case with all tests!). Accuracy remains particularly problematic for recent infections (past 14 day window). Leading expert Scott Gottlieb (former director of the FDA) recommended this morning that “If you do go out and get an antibody test, and you get a positive result, meaning you have the antibodies, I would suggest you repeat it.”
Post-approval monitoring of the new test’s accuracy will remain critically important in order to understand its performance in the broader population.
