The CDC says it’s planning to separate those numbers in the coming weeks, but experts say the current method is unhelpful and potentially misleading.
That’s because antibody tests aren’t used to diagnose current infections or determine whether someone is potentially contagious. Instead, they indicate whether someone has been exposed to the virus in the past.
Combining numbers from antibody and viral tests pushes up the total number of tests conducted in the US. But antibody tests are often intended for the general public — not just people with suspected infections — so they can skew a key indicator of how the pandemic is progressing: the percentage of tests that come back positive.
The CDC’s method makes it appear that the US has greater capacity to test than it really does, at least when it comes to identifying current infections.
“It’s not useful information unless you have a political agenda that you’re trying to back up. That’s really the only reason to do that,” said CNN medical analyst Dr. Celine Gounder, a professor of medicine and infectious diseases at the New York University School of Medicine.
“This is just one more example of why we’re very concerned that science is being suppressed at the CDC and is taking a back seat to political priorities in this administration,” she said.