The World Health Organisation (WHO) has officially prequalified the novel type 2 oral polio vaccine (nOPV2), marking a significant milestone after three years of being granted Emergency Use Listing (EUL).
Developed with contributions from scientists at the UK Medicines and Healthcare Products Regulatory Agency (MHRA), the nOPV2 has been rigorously tested and proven effective in immunized populations.
The WHO’s decision comes after the distribution of 950 million doses globally, reinforcing the vaccine’s safety and efficacy.
Why it matters
- The nOPV2 is a modified version of the oral polio vaccine (OPV), specifically targeting poliovirus type 2.
- This modification aims to reduce the risk of vaccine-derived outbreaks, a concern that arises when the weakened virus in the vaccine circulates in under-immunized populations, potentially regaining the ability to cause paralysis.
- Key genetic modifications, such as a stabilized RNA stem-loop structure, were thoroughly tested through pre-clinical methods before clinical development, ensuring the vaccine’s effectiveness against polio while minimizing the potential for the virus to mutate.
The nOPV2, as a shield against polio for children, has now received pre-qualification status from the WHO, streamlining access for member countries without the stringent criteria previously mandated under the EUL.
This pre-qualification ensures broader availability for global organizations to supply and distribute the nOPV2 in developing nations.
What you should know
- Polio, primarily transmitted through contaminated food and water, poses a significant threat to infants and young children, potentially resulting in severe paralysis or fatality.
- Oral polio vaccines, including the nOPV2, have played a crucial role in reducing polio cases globally, and their characteristic of not requiring stringent cold storage facilitates immunization efforts in remote areas.
- Three years ago, amid concerns about vaccine-derived outbreaks in Asia and Africa, the nOPV2 became the first vaccine to gain WHO EUL, paving the way for its current pre-qualification.
- The global polio eradication initiative and International Health Regulations (IHR) classify Nigeria as a state infected with circulating vaccine-derived poliovirus type 2 with 62 outbreaks reported in 2022.
- This decision represents a pivotal step forward in strengthening global immunity against polio, emphasizing the collective commitment to ensuring that children worldwide receive safer and more accessible polio vaccines.
