On February 10, 2026, the World Health Organization (“WHO”) prequalified a new novel oral polio vaccine type 2 (“nOPV2”) product. The newly prequalified product will be manufactured by Biological E. Limited, India using in-house bulk vaccine technology transferred from PT Bio Farma (Persero), Indonesia. WHO has previously prequalified nOPV2 products manufactured by PT Bio Farma and products formulated and filled by Biological E. using bulk supplied by PT Bio Farma. The vaccine was originally developed by a scientific consortium including researchers from the United Kingdom’s National Institute for Biological Standards and Controls the U.S. Centers for Disease Control and Prevention, the U.S. Food and Drug Administration, and the University of California at San Francisco.
WHO prequalifies vaccines to ensure the safety and efficacy of vaccines by evaluating vaccines using international standards. The program is also intended to spur innovation to address unmet public health needs. The nOPV2 vaccine was developed to prevent the transmission of circulating vaccine-derived poliovirus (“cVDPV”), which can lead to outbreaks, primarily in Africa and Asia. According to WHO, increasing the pool of prequalified nOPV2 is crucial to rapid and effective response to cVDPV outbreaks.
Poliomyelitis, or polio, is a highly infectious and devastating disease that most commonly infects children five years old or younger. One in 200 infections lead to permanent paralysis and 5-10% of paralysis cases result in fatal paralysis of the breathing muscles.
Eradication of polio began in the late 1950s, following the introduction of the injectable inactivated polio vaccine (“IPV”), developed by Jonas Salk, in 1955. A “live” vaccine that could be administered orally was developed by Albert Sabin in 1961. By 1979, polio was considered eradicated in the United States in 1979. In 1988, the World Health Assembly, the decision-making body of WHO, adopted a resolution for the worldwide eradication of polio that has been largely successful. Currently, the wild poliovirus (“WPV”), of which there were once three serotypes (WPV1, 2, and 3), is endemic only in Afghanistan and Pakistan. Serotypes 2 and 3 were declared eradicated in 2015 and 2019, respectively.
Today, outbreaks due to strains derived from the oral polio vaccine are a greater public health concern than the wild virus. In 2025 (as of September 17, 2025) there were 143 reported vaccine-derived virus infections, as compared to 28 wild poliovirus infections. The vast majority of the cVDPV cases (136) were caused by cVDPV2, a virus derived from vaccines protective against WPV2. The nOPV2 vaccine was designed to protect against these outbreaks.
Circulating VDPV originates from rare instances (1 in 2.7 million doses) when the “live” virus of the oral polio vaccine mutates and regains virulence. Areas with low immunization rates are particularly susceptible. For this reason, the United States has only used the IPV since 2000. However, the oral vaccine continues to be preferred in many countries as it is inexpensive, shelf-stable, easy to administer, and, unlike the IPV, induces mucosal immunity that prevents person-to-person transmission—an important feature in locations where the virus is circulating.
According to WHO, the design of the nOPV2 vaccine, which is more genetically stable, makes such reversion to virulence events less likely while also protecting against virus infection and transmission. WHO considers diversifying and increasing the availability of nOPV2 as an important step in achieving a polio-free world.
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