Vaccine Info

nOPV2 Polio Vaccine

Authored by
Last reviewed
October 13, 2021
Fact checked by
Robert Carlson, MD

nOPV2 Polio Vaccine Description

nOPV2M4a polio vaccine is derived from the live, infectious virus, but it has been 'triple-locked using genetic engineering to prevent it from becoming harmful.  nOPV2M4a is genetically more stable than existing OPV, with a lower risk of reversion to neurovirulence.

nOPV2 vaccine was developed as attenuated serotype two polioviruses derived from a modified Sabin 2 infectious cDNA clone. nOPV2 Candidate 1 (S2/cre5/S15domV/rec1/hifi3) and nOPV2 Candidate 2 (S2/S15domV/CpG40) were generated by modifying the Sabin-2 RNA sequence to improve phenotypic stability and make the strains less prone to reversion to virulence.

nOPV2 is being deployed under WHO’s Emergency Use Listing procedure (EUL) to enable its rapid field availability. Even after meeting rigorous EUL criteria for safety and immunogenicity, nOPV2’s performance in the field is being closely monitored in line with EUL standards and data collection continues with the ultimate goal of WHO prequalification and full licensure.

As of October 11, 2021, since the launch of nOPV2 vaccinations began in March 2021, approximately 100 million doses have been administered to children across seven countries. In addition to those who have already rolled out the new tool, 16 other countries are also verified as ready to use nOPV2 by GPEI, and a further 17 are in the midst of preparations. More nOPV2 campaigns are due to launch later this year. However, the supply of the vaccine is limited.

Bio Farma, located in Jakarta Selatan 12190, Indonesia, is one of about 29 vaccine manufacturers in 22 countries worldwide that have obtained the World Health Organization Prequalification. The mOPV1 vaccine is a light yellow to pink liquid in a glass vial, contains a suspension of type 1 attenuated poliovirus.

nOPV2 Polio Vaccine Indication

nOPV2M4a Polio Vaccine is indicated to prevent circulating vaccine-derived polio-virus (cVDPV) polio cases. Most cases of cVDPV are caused by mutations in a strain of poliovirus called type 2. The novel vaccine will eventually be licensed based on three criteria: a similar safety profile to the currently licensed mOPV2 of the Sabin strain, non-inferior immunogenicity, and reduced reversion to virulence.

On April 24, 2020, the U.S. CDC stated 'Thirty-one ongoing and new cVDPV type 2 (cVDPV2) outbreaks were documented during July 2019–February 2020; nine outbreaks spread internationally. New cVDPV2 outbreaks were often linked to poor coverage with monovalent Sabin oral poliovirus (OPV) type 2 during outbreak response campaigns. And the Global Polio Eradication Initiative plans to introduce a genetically stabilized, novel OPV type 2 for outbreak response in mid-2020 and expand use in 2021. Cessation of all OPV use after certification of polio eradication will eliminate the risk of VDPV emergence.

nOPV2 Polio Vaccine Side Effects

Assessment of genetic changes and neurovirulence of shed Sabin and novel type 2 oral polio vaccine viruses.

nOPV2 Polio Vaccine News

October 11, 2021 - Following careful review of the safety and genetic stability data from mass immunization campaigns conducted with the novel oral polio vaccine type 2 (nOPV2), the Strategic Advisory Group of Experts on immunization (SAGE) today endorsed the transition to the following use phase for the vaccine. The WHO's independent Global Advisory Committee on Vaccine Safety and SAGE confirmed no major safety concerns associated with nOPV2 after reviewing data.

March 19, 2021 - The WHO reports that four paralytic children infected with circulating vaccine-derived poliovirus type 2 (cVDPV2) have been reported in Tajikistan, with several cVDPV2 cases detected in community and close contacts. On March 8, 2021, the detection of cVDPV2 cases in Tajikistan was reviewed by WHO and designated as a grade 2 emergency. nOPV2 is a new tool that GPEI partners are deploying to better address cVDPV2. nOPV2 is safe and provides comparable protection against poliovirus while being more genetically stable than monovalent oral polio vaccine type 2 and therefore less likely to revert into a form that can cause paralysis in under-immunized communities. This means that nOPV2 could help stop the spread of cVDPV2 outbreaks.

March 13, 2021 - nOPV2 will be rolled out in Africa to fight outbreaks of vaccine-derived poliovirus type 2. Such polio strains are rare but occur in under-immunized communities with limited access to safe water and sanitation.

November 13, 2020 - The World Health Organization's Prequalification program issued an Emergency Use Listing recommendation for the type 2 novel oral polio vaccine (nOPV2). This will allow the vaccine's rollout for limited initial use in countries affected by circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreaks.

October 29, 2020 - New polio vaccine, designed to prevent harmful mutations, poised to get emergency WHO approval.

October 22, 2020 - The twenty-sixth meeting of the Emergency Committee under the International Health Regulations (2005) on poliovirus's international spread was convened. The Emergency Committee reviewed the data on wild poliovirus (WPV1) and circulating vaccine-derived polioviruses (cVDPV).  The following IHR States Parties provided an update at the video conference or in writing on the current situation in their respective countries: Afghanistan, Chad, Egypt, Guinea, Pakistan, Somalia, South Sudan, Sudan, and Yemen.

July 13, 2019 - The safety and immunogenicity of novel live attenuated monovalent (serotype 2) oral poliovirus vaccines in healthy adults: a double-blind, single-center phase 1 study.

April 4, 2019 - The UNICEF Supply Division Team from Copenhagen came to Bio Farma to discuss the joint procurement of mOPV2 global stockpiling in the form of a final product of 60 million doses or 3 million vials that must be prepared in 2019.

nOPV2 Polio Vaccine Clinical Studies

nOPV2 polio vaccine is in several clinical studies that are in various stages. Clinical summaries for nOPV2 vaccine.