Bold hopes for virus antibody tests still unfulfilled

WASHINGTON (AP) — At the height of the coronavirus lockdown, President Donald Trump and his top health advisers trumpeted a new test that would help Americans reclaim their lives — one that would tell them if they already had the virus and were protected from getting it again.

Their arrival would help “get Americans back to work” by showing those who might have “the wonderful, beautiful immunity,” said Trump, a point repeated at the daily briefings last April.

Months later, the U.S. is awash in the tests but the bold predictions about their usefulness have yet to materialize.

“There was definitely a lot of wishful thinking that there was going to be a magical test that was going to save us all, but we’re not there yet,” said Dr. Allison Rakeman of New York City’s Public Health Laboratory.

The tests check the blood for antibodies the body makes to fight off an infection. Scientists are still working to figure out how well antibodies for the coronavirus may shield someone from another infection, or how long that protection might last. Some early studies suggested any immunity fades fast; research published last week was more promising, suggesting that antibodies last at least four months after diagnosis and do not fade quickly.

For now, the Centers for Disease Control and Prevention and the American Medical Association explicitly warn that antibody tests should not be used to make decisions about returning workers to the office or students to school, though some labs still promote them for those uses. The CDC recommends everyone — even those who were sick and recovered — take precautions to prevent getting and spreading the virus.

Experts say it was probably unrealistic to expect answers to key immunity questions early in the outbreak. Those questions have traditionally been answered only...