Vaccine Info

nOPV2 Polio Vaccine

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Last reviewed
January 7, 2022
Fact checked by
Robert Carlson, MD

nOPV2 Polio Vaccine Description

The nOPV2 polio vaccine is derived from the live, infectious virus, but it has been 'triple-locked using genetic engineering to prevent it from becoming harmful.  nOPV2a 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 deployed under WHO's Emergency Use Listing procedure (EUL) to enable rapid field availability. Thus, even after meeting rigorous EUL criteria for safety and immunogenicity, nOPV2's performance in the field is closely monitored in line with EUL standards, and data collection continues with the ultimate goal of WHO prequalification and full licensure.

The Lancet published the results of a study on December 9, 2020, that concluded 'novel OPV2 candidates were as safe, well-tolerated, and immunogenic as monovalent OPV2 in previously OPV-vaccinated and IPV-vaccinated adults. These data supported the further assessment of the vaccine candidates in children and infants.'

Since the launch of nOPV2 vaccinations in March 2021, approximately 100 million doses have been administered to children across seven countries as of October 11, 2021. 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.

The Global Polio Eradication Initiative published nOPV2 Frequently Asked Questions. And the WHO Listed the nOPV2 vaccine (Bio Farma, Indonesia) for emergency use on November 13, 2021, to address the rising cases of a vaccine-derived polio strain in a number of African and East Mediterranean countries.

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 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

December 9, 2021 - The WHO confirmed it recommends that all travelers to polio-affected areas be fully vaccinated against polio. Residents (and visitors for more than 4 weeks) from infected areas should receive an additional dose of oral polio vaccine or inactivated polio vaccine within four weeks to 12 months of travel. 

November 23, 2021 - The WHO announced the polio Committee unanimously agreed that the risk of international spread of poliovirus remains a Public Health Emergency of International Concern and recommended the extension of Temporary Recommendations for a further three months. 

November 3, 2021 - The BMJ reported after a three-year pause, house-to-house polio vaccinations are to restart in Afghanistan, where polio cases have been reported.

November 3, 2021 - GPEI reported a summary of new WPV and cVDPV this week (AFP cases and ES positives): Cameroon: one cVDPV2 case; DRC: one cVDPV2 case; Niger: two cVDPV2 cases; Nigeria: eight cVDPV2 cases and five positive environmental samples.

November 1, 2021 - The U.S. CDC issued a Level 2 Travel Advisory that stated 'Destinations in Africa currently considered high risk for polio.'

October 26, 2021 - The WHO Africa posted an article: Pursuing the endgame: novel polio vaccine rollout in Africa.

October 22, 2021 - Africa News reported Ethiopia launched a polio vaccination campaign with type 2 novel oral polio vaccine (nOPV2) targeting over 17 million under-five children.

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.

October 1, 2021 - Polio outbreak in Tajikistan - 31 children have been found to have polio caused by cVDPV2, and the virus has also been isolated from 26 children without paralysis. Twenty environmental samples have tested positive for the presence of the virus. All detected polioviruses are linked to a virus strain currently circulating in Pakistan.

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 29, 2021 - The journal Nature published the results from a study - Because of the safety, immunogenicity, and promising phenotypic stability of these viruses, nOPV2 use under Emergency Use Listing (EUL) features prominently in the Global Polio Eradication Initiatives new strategy to stop further spread of cVDPV21, and the EUL has recently been granted for nOPV2-c1. The methods described here are now being applied to shed virus from paired phase 4 and phase 2 clinical trials of mOPV2 and nOPV2 in children and infants, allowing a more direct comparison of the molecular evolution and virulence of shed nOPV2 viruses with shed Sabin 2 in the age groups that will be the focus of outbreak responses.

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.