A German man has been vaccinated against COVID-19 more than 200 times, going against medical advice in doing so.
The 62-year-old, from Magdeburg, received 217 jabs over 29 months, The Lancet Infectious Diseases journal reported.
The man is described as a "hyper-vaccinated individual" who received the immunisations deliberately, for private reasons outside of a clinical study context and against national recommendations.
However, the man hasn't received any vaccine-related side effects. He's also had no signs of past COVID-19 infections, testing has shown.
University of Erlangen-Nuremberg researchers studying the man were adamant, though, saying they "do not endorse hypervaccination as a strategy to enhance adaptive immunity".
"We learned about his case via newspaper articles," Kilian Schober, from the university's microbiology department, told the BBC.
"We then contacted him and invited him to undergo various tests in Erlangen. He was very interested in doing so," Dr Schober said.
The man actively and voluntarily consented to provide medical information and donate blood and saliva for the research.
"Prime-boost vaccinations can enhance immune responses, whereas chronic antigen exposure can cause immune tolerance," the report warned.
"In humans, the benefits, limitations, and risks of repetitive vaccination remain poorly understood."
A public prosecutor opened an investigation of this case with the allegation of fraud but criminal charges have not been filed.
