After 217 Covid vaccines, humans had no side effects and strong immunity

Two years ago, German doctors came across news reports about a man being investigated for receiving dozens of coronavirus vaccines without a medical certificate.

Then followed a wave of speculation about what he had been up to. It turned out that prosecutors were investigating whether he received so many extra doses as part of a scheme to collect stamped immunization cards that he could later sell to people looking to circumvent vaccination mandates.

But to 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 participate in a research project?

When prosecutors concluded 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 coronavirus vaccine, they said. Ignoring their pleas to stop, he received two more injections in the following months, increasing his immunological stockpile to a total of 217 doses of eight different types of Covid vaccines in two and a half years.

After studying him for months, 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 from the vaccine. And what was most interesting for the researchers was that his repertoire of antibodies and immune cells was significantly larger than that of a typical vaccinated person, even though the precision 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 unwelcome form of immune tolerance that sometimes develops during long-term viral infections — they reported that they had seen no such decline in responses.

“This really shows how robust the immune system response is to such repeated immunizations,” said Dr. Schober. “Even 200 vaccinations do not pose as much of a challenge to the immune system as a chronic infection.”

Researchers said the man was from Magdeburg, a city in central Germany, but gave few other details, saying his reasons for the vaccination wave were private.

Prosecutors had collected evidence of 130 vaccinations over nine months, investigators wrote. The man’s first vaccination, with a shot made by Johnson & Johnson, came in June 2021. Most of his subsequent shots were mRNA vaccines made by Moderna or Pfizer-BioNTech. He also received several updated vaccines from Pfizer-BioNTech.

In addition to their own tests, the scientists relied on the man’s routine medical tests from before and during the pandemic. But because they didn’t have access to other vaccine collectors, the researchers said their findings couldn’t be used to predict how other people would respond to repeated shots.

Other patients who receive so many doses may experience side effects, said Dr. Schober, making it unwise for people to ignore medical advice to get more than the recommended number of injections. And while the study suggested that the vaccines were generally very safe and could continue to boost the immune response, the benefits of repeated vaccinations did not necessarily outweigh the small risk of an additional shot.

Dr. For example, Schober said the man’s antibody levels dropped in the periods after his most recent admissions, as is typically the case in patients who received the usual number of doses. The finding suggested that the man’s heightened immune response could only be maintained by continued revaccination.

“These super high levels are not sustainable,” said Dr. Schober. “They would return to normal levels.”

Still, the two-and-a-half-year vaccination binge created a kind of immune system stress test that doctors never allowed to happen under their supervision. And while the results were far from conclusive, this one man’s immune system at least looked remarkably resilient.

“Two hundred vaccinations may seem like a lot,” said Dr. Schober. But immune cells capable of responding to chronic viruses, he added, essentially “laugh” at the mimic virus particles they encounter, even during hundreds of shots.