Two years ago, German doctors stumbled across news reports of a man being investigated for receiving scores of coronavirus vaccines with no medical explanation.
Then followed a flurry of speculation about what he had been up to. As it turned out, prosecutors were looking into whether he had been receiving so many extra doses as part of a scheme to collect stamped immunization cards that he could later sell to people who wanted to skirt vaccine mandates.
But to the doctors, the man was a medical anomaly, someone who had defied official recommendations and turned himself into a guinea pig for measuring the outer limits of an immune response. Last year, they asked prosecutors investigating his vaccine splurge to pass along a request: Would he like to join a research project?
Once prosecutors closed their fraud investigation without criminal charges, the man agreed.
By the time the doctors first saw him, the 62-year-old man had received 215 doses of coronavirus vaccine, they said. Flouting their pleas to stop, he received another two shots in the next months, expanding his immunological stockpile to a combined 217 doses of eight different Covid vaccine types over two and a half years.
After months of studying him, the doctors, led by Dr. Kilian Schober, an immunologist at the University of Erlangen-Nuremberg in the German state of Bavaria, reported their findings this week in The Lancet Infectious Diseases, a medical journal.
The man had seemingly never been infected with the coronavirus. He reported no vaccine side effects. And, most interestingly to the researchers, his repertoire of antibodies and immune cells was considerably larger than that of a typical vaccinated person, even if the precision of those immune responses remained effectively unchanged.