Three Seattle fishermen who were spared coronavirus during an outbreak that affected 85 percent of the people on their boat could provide the first direct evidence that antibodies can provide immunity against the infection, according to a new report.
Blood samples were collected before the FV American Dynasty, owned by American Seafoods, sailed in May, showing that three of the 122 people on board had high levels of neutralizing antibodies – which block the virus from human cells – indicating that they once were infected and recovered, the Seattle Times reported.
None of the crew members tested positive for the virus – and although six tested positive for antibodies that bind to the new coronavirus, only these three had neutralizing antibodies, the outlet reported.
Eighteen days after his voyage, the ship returned to shore after one crew member fell ill and was hospitalized again. While the other crew members were checked for the next 50 days, 104 people were confirmed to be infected, according to the report.
None of the members with neutralizing antibodies reported symptoms or became infected, a detail that researcher Drs. Alex Greninger called it “hopeful news,” in a not-yet-peer-reviewed report posted on MedRxiv.
“There is a strong indication that the presence of neutralizing antibodies is associated with protection against the virus,” Greninger, assistant director of the University of Washington Medicine Clinical Virology Laboratory, told the Times.
“While this is a small study, it offers a remarkable, human experiment in reality,” Danny Altmann, professor of immunology at Imperial College London, wrote in a commentary, the report said. “Who knew that immunology research on fishing boats could be so informative?”
Statistical analysis shows that it is probably not a coincidence that all three of those members remained virus-free, according to the Times. However, the study does not explain why 15 other crew members apparently never contracted the disease – and Greninger suggested that their specific jobs protected them from exposure.
The other crew members who were found to have antibodies carried the virus, indicating that their initial results may have been false positions, according to Greninger.
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