Vaccine-Derived Polio:
A vaccine-derived polio case has been confirmed in a two-year-old child from Tikrikilla, Meghalaya. Health authorities clarified that this is not wild poliovirus but an infection seen in individuals with low immunity.
- India’s polio-free status: India was declared polio-free by the World Health Organization (WHO) in 2014, with the last wild poliovirus case reported in 2011.
- The Oral Polio Vaccine (OPV) contains a weakened form of the poliovirus, which stimulates an immune response.
cVDPV development: On rare occasions, in under-immunized populations, the excreted vaccine virus can circulate, undergo genetic changes, and potentially revert to a form capable of causing paralysis. - This is known as circulating vaccine-derived poliovirus (cVDPV).
- Since 2000, over 10 billion doses of OPV have been administered globally, resulting in 24 cVDPV outbreaks in 21 countries, with fewer than 760 cases.
- To stop cVDPV transmission, WHO recommends multiple rounds of high-quality immunisation campaigns.
