VACCINE-DERIVED POLIO SPREAD IS STILL A RISK WORLDWIDE: WHO
A WHO committee, after looking into updates from several countries, stated that while risk of global spread of wild poliovirus remains, risk of circulating vaccine-derived poliovirus (VDPV) ones is higher.
Poliomyelitis, also known as polio, is a disease that attacks the nervous system and is highly contagious. Wild polio virus comes in three varieties: type 1, type 2, and type 3.Only the wild type 1 poliovirus is still in use.
Poliovirus vaccinations can be divided into two categories:
Oral poliovirus and inactivated poliovirus (IPV).Formalin-inactivated (killed) wild-type poliovirus strains are the source of IPV.
The attenuated (weakened) vaccine virus in OPV causes the body’s immune system to respond.
However, when the vaccine virus is spread for an extended period of time or reproduces, OPV can occasionally result in the emergence of VDPVs.
VDPV types include: ambiguous VDPV, circulating VDPV (cVDPV), and immunodeficiency VDPV (iVDPV).
Children with immune deficiencies and populations with low immunity levels typically carry VDPVs. Along with the rest of the South-East Asia Region, India was officially declared polio-free in 2014.