British Man has been Shedding Polio Virus for 28 Years Despite Being Vaccinated

A British man who was vaccinated from polio has been shedding the virus for nearly 30 years. According to the research team from the National Institute for Biological Standards and Control in Potters Bar, Hertfordshire, the 29-year-old man had an immune disorder that caused the oral vaccine, which contains live polio in a weakened state, to be less effective.

The man had received a full course of vaccinations, which included three doses of the vaccine as well as a booster.

After several years, the virus had mutated from the weakened version to a form that can lead to paralysis. The researchers made this discovery by testing his stool samples, which all contained high levels of the virus. They have neutralized the virus by using blood plasma that was taken from people who have already been immunized against the disease.

The team is now warning officials that similar cases can occur. The researchers are also concerned that there are more people like him because sewage samples from other countries, such as Finland and Israel, have had evidence of the virus as well.

"While maintaining high immunization coverage will likely confer protection against paralytic disease caused by these viruses, significant changes in immunization strategies might be required to effectively stop their occurrence and potential widespread transmission," the researchers wrote.

The study was published in PLOS Pathogens.