Strains in immune-compromised Briton differ slightly from vaccine’s
A British man has been excreting live poliovirus for an estimated 28 years.
An immune deficiency allowed weakened virus from oral polio vaccines to replicate and change within the man’s body. This case is not unique, but it’s the longest-lasting example of vaccine-derived poliovirus on record, researchers report August 27 in PLOS Pathogens.
The study reveals that there is no limit to how long polio can circulate in the system of a person who doesn’t produce enough of specific antibodies, says virologist Olen Kew of the Centers for Disease Control and Prevention in Atlanta. “This is the world record holder — everyone agrees,” he says.
The virus has changed within the man’s body, evolving into slightly different versions from the original vaccine strain, the researchers show. Several virus strains contained changes to surface regions that human immune