Biological E, an India-based vaccine and pharmaceutical company, has announced that its novel oral poliovirus vaccine Type 2 (nOPV2) has reached Phase II of the World Health Organization’s (WHO) Prequalification (PQ) process. This development represents a significant step forward in the global initiative to provide new tools for combating outbreaks of circulating vaccine-derived poliovirus type 2 (cVDPV2).

The need for an advanced Type 2 oral polio vaccine stems from the ongoing challenge posed by cVDPV2. Although wild poliovirus Type 2 was officially declared eradicated in 2015, outbreaks of cVDPV2 continue to occur in various regions worldwide. These outbreaks are primarily linked to the live attenuated Sabin strain Type 2 oral polio vaccine (OPV2). In rare instances, the vaccine virus can genetically revert to a neurovirulent form after circulating in under-immunized populations, potentially causing paralysis.

Biological E's nOPV2 is engineered to be more genetically stable than the conventional Sabin OPV2. This enhanced stability is intended to significantly reduce the likelihood of the vaccine virus reverting to a form that can cause paralysis, thereby offering a safer alternative for outbreak response. The vaccine's primary aim is to provide effective immunity against Type 2 poliovirus while minimizing the risk of generating new cVDPV2 outbreaks.

The WHO Prequalification process is a stringent evaluation system designed to ensure that vaccines, medicines, and diagnostic tools meet international standards for quality, safety, and efficacy. The "Phase II Prequalification" status specifically indicates that the WHO has reviewed and accepted data derived from the early clinical studies (Phase I and II) of Biological E's nOPV2, alongside an assessment of its manufacturing quality systems. This successful passage through the initial stages of the PQ process confirms the vaccine candidate's potential and moves it closer to broader global consideration for procurement and deployment by UN agencies and other health initiatives.

Biological E possesses a long-standing history in vaccine manufacturing, supplying a range of essential vaccines to global markets. The company's development of nOPV2 aligns with the broader global polio eradication strategy, which includes the phased withdrawal of conventional OPV strains and the introduction of safer, more genetically stable alternatives. This initiative underscores the company's commitment to public health innovation and its role in critical global health efforts.

The advancement of nOPV2 to Phase II PQ moves it closer to potential deployment in global efforts to contain and ultimately eliminate cVDPV2 outbreaks. The subsequent stages of the prequalification process will involve further clinical trials, typically Phase III, to gather more extensive safety and efficacy data, followed by comprehensive manufacturing site inspections and final regulatory reviews. If successful, Biological E's nOPV2 could become a crucial tool in the final stages of achieving a polio-free world.