This Trawler’s Haul: Evidence That Antibodies Block the Coronavirus

A fishing vessel that left Seattle in May returned with an unexpected catch: the first direct evidence in humans that antibodies to the coronavirus can thwart infection.

More than a hundred crew members aboard the American Dynasty were stricken by the infection over 18 days at sea. But three sailors who initially carried antibodies remained virus-free, according to a new report.

Although the study is small, it addresses one of the most important questions in the pandemic: whether the immune response to one bout with the virus protects against reinfection.

“Knowing the answer to this question is critical for vaccine design and epidemiology,” tweeted Jesse Bloom, an evolutionary biologist at the Fred Hutchinson Cancer Research Center in Seattle and one of the study’s authors.

The study was posted online last week and has not yet been published in a peer-reviewed journal. Still, the finding set off optimistic chatter among scientists, who have been relying on monkey studies for evidence of antibodies’ potency. ...

Several research teams have reported that an encounter with the virus triggers a robust immune response in most people, including in those who may have been only mildly ill. And the vaccine candidates now in trials also seem to elicit strong neutralizing antibodies, the kind that can block the virus....