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One German man has redefined “man on a mission.” A 62-year-old from Magdeburg deliberately got 217 Covid-19 vaccine shots in the span of 29 months, according to a new study, going against national vaccine recommendations. That’s an average of one jab every four days.

In the process, he became a walking experiment for what happens to the immune system when it is vaccinated against the same pathogen repeatedly. A correspondence published Monday in the journal Lancet Infectious Diseases outlined his case and concluded that while his “hypervaccination” did not result in any adverse health effects, it also did not significantly improve or worsen his immune response.

The man, who is not named in the correspondence in compliance with German privacy rules, reported receiving 217 Covid shots between June 2021 and November 2023. Of those, 134 were confirmed by a prosecutor and through vaccination center documentation; the remaining 83 were self-reported, according to the study.

“This is a really unusual case of someone receiving that many Covid vaccines, clearly not following any type of guidelines,” said Dr. Emily Happy Miller, an assistant professor of medicine and of microbiology and immunology at Albert Einstein College of Medicine who did not participate in the research.

The man did not report any vaccine-related side effects and has not had a Covid infection to date, as evidenced by repeated antigen and PCR testing between May 2022 and November 2023. The researchers caution that it’s not clear that his Covid status is directly because of his hypervaccination regimen.

“Perhaps he didn’t get Covid because he was well-protected in the first three doses of the vaccine,” Miller said. “We also don’t know anything about his behaviors.”

Dr. Kilian Schober, senior author of the new study and a researcher at the Friedrich-Alexander University Erlangen-Nürnberg, said it is important to remember that this is an individual case study, and the results are not generalizable.

The researchers also say they do not endorse hypervaccination as a strategy to enhance immunity.

“The benefit is not much bigger if you get vaccinated three times or 200 times,” Schober said.

Raising suspicions

According to his immunization history, the man got his first Covid vaccine in June 2021. He got 16 shots that year at centers across the eastern state of Saxony.

He ramped up his efforts in 2022, rolling up his sleeves for shots in both his right and left arms almost every day in January, for a total of 48 shots that month.

Then he kept going: 34 shots in February and six more shots in March. Around this time, German Red Cross staff members in the city of Dresden became suspicious and issued a warning to other vaccination centers, encouraging them to call the police if they saw the man again, CNN affiliate RTL reported in April 2022.

In early March, he showed up at a vaccination center in the town of Eilenburg and was detained by police. He was suspected of selling the vaccination cards to third parties, according to RTL. This was during a time when many European countries required proof of vaccination to access public venues and travel.

The public prosecutor in Magdeburg opened an investigation into the man for the unauthorized issuing of vaccination cards and forgery of documents but did not end up filing criminal charges, according to the study.

Effects of hypervaccination

The researchers read about the man in the news and reached out to him through the prosecutor investigating his case in May 2022. By this point, he was 213 shots in.

He agreed to provide medical information, blood and saliva samples. He also proceeded to get four more Covid shots, against the researchers’ medical advice, Schober said.

The researchers analyzed his blood chemistries, which showed no abnormalities linked to his hypervaccination. They also looked at various markers to evaluate how his adaptive immune system was functioning, according to the study.

The adaptive immune system is the subsection of the immune system that learns to recognize and respond to specific pathogens when you encounter them throughout your life, Miller said. There are two main cell types in the adaptive immune system, T cells and B cells.

In chronic diseases, such as HIV and hepatitis B, immune cells can become fatigued from frequent exposure to the pathogen and lose the ability to combat it effectively, Schober said. Hypervaccination, in theory, could have a similar effect.

However, that’s not what the researchers found. Hypervaccination in this case increased the quantity (the number of T cells and B cell products) but did not affect the quality of the adaptive immune system, according to the study.

“If you take the allegory of the immune system as an army, the number of soldiers is higher, but the soldiers themselves are not different,” Schober said.

In total, the man got eight vaccine formulations, including mRNA vaccines from Pfizer/BioNTech and Moderna, a vector-based vaccine from Johnson & Johnson and a recombinant-protein vaccine from Sanofi.

“The observation that no noticeable side effects were triggered in spite of this extraordinary hypervaccination indicates that the drugs have a good degree of tolerability,” Schober said in a news release.

While very interesting from a scientific perspective, individual case studies like this must always be taken with a grain of salt, Miller said. Public health recommendations, which are based on very large, randomized control trials, are what people should look to for guidance, she added.

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“I don’t think any physician or public health official would recommend doing what this gentleman did. This is really uncharted territory,” Miller said. “Talk to your doctor, follow the recommended vaccine schedules, and that should be the best thing to keep you both protected from Covid and healthy and safe.”

The US Centers for Disease Control and Prevention recommends Covid vaccination for everyone ages 6 months or older in the United States, following the vaccination schedules outlined on its website. Last week, the CDC updated its guidance to recommend an additional dose of the current Covid vaccine for people 65 and older.

Less than a quarter of adults and only 13% of children in the US have gotten the most recently recommended Covid vaccine, according to CDC data.