German researchers have examined a “hypervaccinated” man they say received more than 200 coronavirus shots without any noticeable side effects or harm to his immune system.
Their findings, published Monday in the Lancet Infectious Diseases, a medical journal, indicate that coronavirus vaccines have a “good degree of tolerability,” the researchers said, although they noted this was an isolated case of “extraordinary hypervaccination.”
The 62-year-old man came to researchers’ attention when German prosecutors opened up a fraud investigation, gathering evidence that he had obtained 130 coronavirus shots in a nine-month period — far more than recommended by health authorities.
“We learned about his case via newspaper articles,” Kilian Schober, one of the study’s authors, said in a statement. “We then contacted him and invited him to undergo various tests. … He was very interested in doing so.”
The man agreed to provide blood samples, including new samples, the results from past blood tests and blood samples that had been frozen in recent years.
The man said he had received 217 vaccinations for “private reasons.” German authorities did not file criminal charges.
Going into the study, the researchers had speculated that having so many shots could cause his immune system to become fatigued. Vaccines create immune memory cells that are on standby, ready to rapidly activate the body’s defenses in the event of an infection.
But in fact, the researchers found that the man had more of these immune cells — known as T-cells — than a control group that had received the standard three-dose vaccine regimen. They also did not detect any fatigue in these cells, which they said were just as effective as those of people who had received a typical number of coronavirus shots.
“Overall, we did not find any indication for a weaker immune response, rather the contrary,” said Katharina Kocher, one of the lead authors of the study.
Even by the 217th vaccination, researchers say the shot still had an effect: The man’s antibodies against the coronavirus “increased significantly as a result.” (Researchers say the man insisted on receiving another shot during the study. They took blood samples, which helped them determine how his immune system was responding.)
The researchers made it clear that despite their findings, they “do not endorse hypervaccination as a strategy to enhance adaptive immunity.”
Although they could not find any signs that the man had ever contracted the coronavirus, they said they weren’t able to establish a causal relationship between his “hypervaccination regimen” and avoiding infection.
More than 60 million people in Germany have been vaccinated against the coronavirus, and most of them have received several doses.
In the United States, the Centers for Disease Control and Prevention recommended last month that people 65 and older get a second dose of a coronavirus vaccine made available in the fall because they are at higher risk for severe disease from the virus.
Uptake since the CDC recommended that people age 5 and older get an updated vaccine has been low — only about 22 percent of those 18 and older have received a dose of an updated vaccine. And only about 42 percent of those 65 and older have received a dose, The Washington Post previously reported.
Lena H. Sun contributed to this report