Two years ago, German doctors came across news stories about a man being investigated for taking multiple coronavirus vaccines without a medical explanation.
Then there was a flurry of speculation as to what he had done. As it turned out, prosecutors were looking into whether he had received so many extra doses as part of a scheme to collect stamped vaccination cards that he could later sell to people who wanted to bypass vaccine orders.
But to doctors, the man was a medical anomaly, someone who had defied official recommendations and been turned into a guinea pig for measuring the outer limits of an immune response. Last year, they asked prosecutors investigating his vaccine overdose to forward a request: Would he want to participate in a research program?
Once prosecutors closed their fraud investigation without criminal charges, the man agreed.
By the time doctors first saw him, the 62-year-old man had received 215 doses of the coronavirus vaccine, they said. Defying their pleas to stop, he received two more shots in the following months, building up his immune reserve to a combined 217 doses of eight different types of Covid vaccine over two and a half years.
After months of studying it, 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 apparently never been infected with the coronavirus. He reported no side effects of the vaccine. And, most interesting to the researchers, his repertoire of antibodies and immune cells was significantly greater than that of a typical vaccinated person, even if the accuracy of those immune responses remained essentially unchanged.
The researchers found that even the 217th shot boosted the man’s immune response. And while they looked carefully for signs of a progressive weakening of his immune responses over time—an unwanted type of immune tolerance that sometimes develops during long-term viral infections—they reported seeing no such decline in responses.
“This really shows how strong the immune system’s response is to such repeated immunization,” said Dr Sober. “Even 200 vaccinations don’t pose as much of a challenge to the immune system as a chronic infection.”
Investigators said the man was from Magdeburg, a city in central Germany, but offered few other details and said the reasons for the vaccination were private.
Prosecutors had collected evidence of 130 vaccinations over a nine-month period, investigators wrote. The man’s first vaccination, with a vaccine from Johnson & Johnson, was in June 2021. Most of the subsequent vaccines were mRNA vaccines from Moderna or Pfizer-BioNTech. He also received several of Pfizer-BioNTech’s updated vaccines.
In addition to their own tests, the scientists relied on the man’s routine medical examinations before and during the pandemic. But because they did not have access to other vaccine hoarders, the researchers said their findings could not be used to predict how other people would react to repeated vaccinations.
Other patients given that many doses may experience side effects, Dr. Sober said, making it unreasonable for people to defy medical advice to get more than the recommended number of shots. And while the study both suggested that the vaccines were generally very safe and could continue to boost immune responses, the benefits of repeated vaccination did not necessarily outweigh the small risk of an additional shot.
For example, Dr. Sober said, the man’s antibody levels declined in the periods after his most recent recorded shots, as is generally the case in patients receiving the usual number of doses. The finding suggested that the man’s heightened immune response could only be kept high by revaccination all the time.
“These extremely high levels are not sustainable,” Dr Sober said. “They would drop to normal.”
However, the two-and-a-half-year vaccine binge created a type of immune system stress test that doctors would never allow to happen on their watch. And while the results were far from conclusive, at least this man’s immune system seemed remarkably resilient.
“Two hundred vaccinations may seem like a lot,” said Dr. Sober. But immune cells capable of responding to chronic viruses, he added, “basically laugh” at the viral mimic particles they have to deal with, even over the course of hundreds of shots.