Polio: A Public Health Emergency?
16 Feb 2023 • The recent declaration of a public health emergency in New York State after a case of paralytic poliomyelitis caused by a circulating vaccine-derived poliovirus (cVDPV), along with cVDPV detection in wastewater both in New York and in London, is a sobering reminder that polio still represents a threat even in countries that have not seen it for decades. The continued circulation of wild and attenuated polioviruses suggests that the approach used by the polio-eradication campaign needs reevaluation. The Global Polio Eradication Initiative (GPEI), launched 34 years ago, aimed to eradicate poliomyelitis by 2000. The novel OPV2 was introduced for outbreak control in 2020 and was found to be more stable than the original serotype 2 Sabin strain. This important development fostered hope that cVDPV outbreaks that occur primarily in Africa and south central Asia might soon be controlled. But the New York case and the discovery of the silent circulation of poliovirus in high-income countries that use IPV demand reassessment of our approach to polio eradication. Although IPV provides excellent protection against paralytic disease, it does not prevent silent circulation of the virus that can eventually infect unimmunized and immunocompromised people. The current plan is to withdraw bivalent OPV within 3 years after the circulation of wild type 1 poliovirus is stopped, and then continue immunizations with IPV only.
Source: NEJM | Read full story