WHO Prequalification for nOPV2 Vaccine
Why focus: GS3 S&T — oral polio vaccine technology (nOPV2) and WHO prequalification. Tests biological concepts and manufacturer proxies.
In News
What Happened
Why It Matters
Background
History & Context
What Changed
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Manufacturing Scope: BEFORE, under its June 2024 Phase I prequalification, Biological E only performed 'fill-finish' operations using bulk drug substance imported from Indonesia's PT Bio Farma. NOW, under Phase II, Biological E manufactures both the Drug Substance and Drug Product at a single integrated site in India.
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Global Supply Chain Vulnerability: BEFORE, the world relied heavily on a single full manufacturer (PT Bio Farma) for end-to-end production of nOPV2. NOW, global production is diversified with two independent suppliers, highly reducing bottleneck risks during sudden outbreaks.
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Production Capacity for Outbreak Response: BEFORE, the Global Polio Eradication Initiative (GPEI) faced potential supply constraints for specialized vaccines. NOW, Biological E's expanded approval allows it to pump an additional 600 million doses per year into the global stockpile.
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Viral Stability in the Field: BEFORE (using older mOPV2), outbreak response vaccines frequently lost their attenuating mutations in the gut, seeding new vaccine-derived outbreaks. NOW, the widespread use of nOPV2 provides a tool that is 80% less likely to revert to neurovirulence due to targeted genetic modifications.
What Did NOT Change
The fundamental mechanism of action of the vaccine remains unchanged; nOPV2 is still a live, attenuated oral vaccine that replicates in the human gut to induce critical primary intestinal mucosal immunity, unlike injectable killed vaccines. Furthermore, nOPV2 remains strictly categorized as an outbreak response tool—it has not replaced bivalent OPV or IPV in the daily, routine Universal Immunization Programme globally.
Prelims Angle
NCERT Connection
Common Misconceptions
✗ Vaccine-derived poliovirus outbreaks are caused by the Inactivated Polio Vaccine (IPV) mutating in children's bodies.
✓ Vaccine-derived poliovirus ONLY arises from the Oral Polio Vaccine (OPV), which contains a live, weakened virus capable of replicating and mutating in the gut. IPV contains a dead/killed virus that cannot mutate or cause disease.
The general public often assumes all vaccines work the same way and carry the risk of causing the disease they are meant to prevent, failing to distinguish between live-attenuated and inactivated mechanisms.
✗ nOPV2 is now being given to all children globally as part of routine daily immunization.
✓ nOPV2 is strictly reserved as an outbreak-response tool, deployed only in targeted regions actively experiencing circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreaks.
People confuse specialized emergency stockpiles with routine Universal Immunization Programme (UIP) vaccines, which currently rely on bivalent OPV and IPV for daily prevention.
Practice Questions
Q1
How Many CorrectConsider the following statements regarding the Novel Oral Polio Vaccine type 2 (nOPV2) and its WHO Prequalification: 1. nOPV2 holds the distinction of being the first vaccine in history to receive a WHO Emergency Use Listing (EUL). 2. India's Biological E. Limited is the first company in the world to receive end-to-end Phase II manufacturing WHO prequalification for nOPV2. 3. nOPV2 eliminates the risk of vaccine-derived poliovirus by utilizing an inactivated, killed virus that cannot replicate in the human gut. How many of the statements given above are correct?
Q2
Match the FollowingMatch List I (Vaccine Type) with List II (Characteristic/Use) regarding the global polio eradication strategy: List I: A. mOPV2 (Monovalent OPV2) B. nOPV2 (Novel OPV2) C. IPV (Inactivated Polio Vaccine) D. bOPV (Bivalent OPV) List II: 1. Replaced the trivalent vaccine in routine global immunization schedules in 2016. 2. First vaccine to ever receive the WHO Emergency Use Listing (EUL). 3. Traditional outbreak response tool that was frequently prone to seeding new cVDPV2 outbreaks. 4. Administered via injection; provides excellent systemic immunity but poor gut mucosal immunity. Select the correct answer using the code given below:
Q3
Assertion & ReasonAssertion (A): The traditional Sabin monovalent oral polio vaccine type 2 (mOPV2) is currently the preferred tool by the WHO for routine response to circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreaks. Reason (R): The live attenuated virus in traditional OPV can genetically mutate in under-immunized populations, regain neurovirulence, and cause paralysis. Select the correct answer from the codes given below: