Polio preys on human negligence, as vaccination performance depends on a tight alignment of technology and human behavior, Katherine Wu, PhD, a writer for The Atlantic, wrote in a Sept. 16 opinion piece.
Deadlines for eradicating the virus have come and gone — with another global eradication goal set to be missed in 2023. While polio remains endemic in two countries, Pakistan and Afghanistan, cases have been reported in areas, including the U.S. where it once was thought to be eliminated.
"Right now, though, the world's immunological shield is too porous to stop polio's spread," Dr. Wu wrote. "At the center of the new epidemics are vaccine-derived polioviruses that have begun to paralyze unimmunized people in places where immunity is low — a snag in the eradication campaign that also happens to be tightly linked to one of its most essential tools."
The two polio vaccinations were intended to complement each other, but successful eradication "will demand a near-perfect syncing of vaccine supply, access, equity, political will, public enthusiasm and more," Dr. Wu wrote.
"But [vaccinations] are not distributed evenly, which opens up vulnerabilities for the virus to exploit," she wrote. "Here, the U.S., in a sense, had one job: maintain its polio-free status while the rest of the world joined in. That it did not is an admonition, and a reminder of how unmerciful the virus can be."