This Troll: Evidence That Antibodies Block Coronavirus

The fishing vessel leaving Seattle in May returned with unexpected catch. Human first direct evidence that antibodies to coronavirus can prevent infection

Over 100 crew members aboard the American dynasty were attacked by the ocean for 18 days. But only three sailors The person who first carried the antibody is not infected with the virus According to a new report.

This study, though small, addresses one of the most important issues in pandemics: whether the immune response to a single stroke with the virus prevents reinfection.

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

This study was posted online last week and has not yet been published in a peer-reviewed journal. Nonetheless, this finding caused an optimistic chat among scientists who relied on monkey studies as evidence of antibody potency.

“I thought it was very exciting, enough news to tell my family about it,” said Mikartar, an immunologist at Stanford University who wasn’t involved in the job.

Several research teams have reported that encountering the virus causes a strong immune response in most people, including people with mild illness. Also, vaccine candidates currently in clinical trials appear to induce a class of potent neutralizing antibodies that can block the virus.

However, the amount of these antibodies needed to prevent the virus from returning is unknown. Scientists measure titers of neutralizing antibodies. This is an index of blood level.

The three sailors, who remained protected from the virus, had vastly different potencies. The two were in modest amounts, the findings the researchers said were encouraging.

“People are very worried about their titers and their titers are falling,” said Dr. Alexander Glenninger, a virologist at the University of Washington, Seattle.

As a result, he said that even moderate titers could prevent reinfection in situations of high virus exposure. “These are the achievable titers? Hopefully, confirming it will be useful and you will be very optimistic about the vaccine.”

The American dynasty carried 113 men and 9 women. All crew members were tested for both viruses and antibodies as part of regular pre-departure screening. (Researchers could not access results from two members.)

When the crew became ill enough to require hospitalization, the trawler returned to shore after 18 days at sea. The sailors were again tested for the presence of the virus and antibodies, and up to 50 days after returning home.

The three sailors who were confirmed to have neutralizing antibodies were not tested positive for virus during the course of the study. Of the remaining 117, 103 were infected.

These numbers may be small, but they are very important, Dr. Glenninger said.

“Many people see this,” Oh, yes, it could be due to random coincidence,” he said. In fact, it is very unlikely that the result is accidental, he added.

Other experts agreed. “Just looking at the numbers reveals that it’s unlikely that all three of these were accidentally protected,” said Florian Krummer, an immunologist at the Eikarn School of Medicine in Mount Sinai, New York. ..

Dr. Krammer and his colleagues track antibody levels in people who have once recovered from coronavirus to see when they are vulnerable to reinfection. The team started with people in New York, but the virus is spreading at very low levels in the city, so Dr. Cramer and his colleagues needed to extend the study elsewhere.

Vaccine trial data will also identify the antibody titer required to disarm the virus. But in the meantime, “this is the first proof of humans,” said Dr. Krammer. “It’s my weekend.”

The study has raised other questions. Based on the Abbott Architect’s assay, six out of 120 tested before the boat departed had antibodies to the virus indicating previous exposure.

However, when researchers re-analyzed those samples using more sophisticated tests, it was confirmed that only 3 out of 6 had the antibody, and 3 test results were false positives. Suggests.

The Abbott test is advertised as returning less than 1 false positive for every 100 samples. “It’s a bit worrisome that Abbott may be a bit less specific than we thought,” Dr. Tal said.

As with most teams, the researchers also looked at antibodies in the blood. However, these levels may not be the same as nasal or saliva levels, and are two major entry points for infection, Dr. Tal added.

“We are looking for the wrong place,” she said. “If you want to see protection from reinfection, you need to look at your nose.”