Facts for Prelims (FFP)
Source: BBC
Context: Scientists have “super-engineered” polio vaccines to prevent them from mutating into a dangerous form that can cause outbreaks and paralysis.
- The wild poliovirus is currently limited to small pockets in Afghanistan and Pakistan, and oral vaccines play a crucial role in eradicating polio worldwide.
- However, the oral vaccine has genetic instability, with just one mutation capable of reversing its safety and causing paralysis. Vaccine-derived polio cases now outnumber wild poliovirus cases.
What are Vaccine-derived polio cases:
These are instances where the poliovirus in the oral polio vaccine (OPV) mutates and causes paralysis in vaccinated individuals or spreads to others in the community. These cases occur when the weakened virus in the vaccine reverts to a form that can cause disease.
To address this, researchers have genetically modified the weakened virus, making it more resistant to causing paralysis. The modified vaccines have shown promising results in human trials, providing more stability and addressing the instability concern (leading to Vaccine-derived polio cases.
However, challenges remain in achieving full coverage and delivering vaccines to impoverished and conflict-affected areas.
About Polio:
Poliomyelitis, also known as polio, is an infection caused by a virus (poliovirus). It is a serious, highly contagious disease that can affect a person’s nervous system.
There are three types of wild poliovirus:
- WPV 1: still exists but efforts are going on to eradicate it.
- WPV 2: eradicated.
- WPV 3: eradicated.
Polio typically affects children aged 5 years or younger. It can result in muscle weakness, permanent disability, and even death.
