The World Health Organization prequalifies novel type 2 oral polio vaccine (nOPV2)

January 9, 2024 by PATH

Emergency use of nOPV2 has protected millions against polio. Prequalification will ensure broad, long-term accessibility.

Just ahead of the new year, the World Health Organization (WHO) prequalified the novel oral polio vaccine type 2 (nOPV2) for use in response to poliovirus type 2 outbreaks, shortly after the vaccine obtained full licensure in Indonesia.

WHO’s decision comes three years after nOPV2 became the first vaccine to receive a WHO Emergency Use Listing (EUL) to protect children from polio while lowering the risk of seeding new type 2 vaccine-derived outbreaks. Approximately a billion doses of nOPV2 have been delivered since EUL approval, and surveillance data confirms that the vaccine is working as intended.

The development of nOPV2 builds upon decades of research on oral polio vaccines. In 2011, a consortium of researchers banded together to test a modified version of the existing type 2 Sabin oral polio vaccine. “We proposed design modifications that we believed held potential for creating a more genetically stable vaccine,” said Andrew Macadam, PhD, a principal scientist at the Medicines and Healthcare Products Regulatory Agency in the UK, and one of the developers of nOPV2. “It is gratifying to know that this research culminated in a product that is protecting millions of children around the world and helping accelerate the end of a horrible disease.”

Since 2015, PATH has served as the convener of the nOPV2 product development consortium —facilitating data-sharing and coordination among partners, and providing technical assistance, such as developing assays to assess the stability of vaccine attenuation and supporting evaluation of surveillance data. PATH also sponsored an nOPV2 Phase 3 study, conducted by Medical Research Council Unit The Gambia (MRCG) at the London School of Hygiene & Tropical Medicine (LSHTM), to generate data needed for WHO to consider prequalification. We integrated data from the Phase 3 study and clinical trial data from other partners for the WHO prequalification application, which was submitted by Bio Farma, the manufacturer of nOPV2.

“The ability to supply nOPV2 with the speed, quality, and scale necessary for distribution under an EUL and beyond is thanks to Bio Farma’s longstanding commitment to this project and to polio eradication,” said John Konz, PhD, nOPV project director and global head of Polio at PATH. “I would like to commend the Bio Farma team for their dedication to parallel efforts to meet demand under the EUL while completing critical activities needed to achieve full licensure and prequalification.”

Bio Farma is also manufacturing novel oral polio vaccines (nOPVs) against polio types 1 and 3 that are undergoing several clinical studies sponsored by PATH. If successful and warranted, these vaccines may also become available under EUL, and eventually be WHO-prequalified.

In addition to advancing research on nOPVs, PATH works on a suite of tools and resources aimed towards fighting polio for years to come: a value proposition for next-generation non-infectious polio vaccines to inform future investments; a treatment to halt chronic shedding of poliovirus; point-of-care diagnostics; affordable, effective surveillance; and international standards and universal reagents for routine testing.

Inherent to the success of new technologies is the extent to which they reach communities at greatest risk of a polio outbreak. “As we celebrate nOPV2’s prequalification, it is important to remember that for the vaccine to reach its full potential, strong coverage is critical,” emphasized Ananda Bandyopadhyay, MD, MPH, co-lead of the Global Polio Eradication Initiative (GPEI) nOPV Working Group and deputy director of Polio at the Bill & Melinda Gates Foundation. “Delivering this vaccine to under-immunized communities experiencing outbreaks is a top priority, and nOPV2 represents our best tool yet to drive down the number of lingering cases in these settings.”