Correct Answer : Option (B) - Both 1 and 2
The risk of global spread of poliovirus remains a public health emergency of international concern, a World Health Organization (WHO) committee has found after looking into updates from 10 countries. While the risk of global spread of wild poliovirus remains, the risk of circulating vaccine-derived ones is higher.
Polio is a crippling and potentially deadly viral infectious disease that affects the nervous system.
There are three individual and immunologically-distinct wild poliovirus strains
* Wild Poliovirus type 1 (WPV1)
* Wild Poliovirus type 2 (WPV2)
* Wild Poliovirus type 3 (WPV3)
Symptomatically, all three strains are identical, in that they cause irreversible paralysis or even death.
However, there are genetic and virological differences, which make these three strains separate viruses which must each be eradicated individually.How does it Transmit? :
The virus is transmitted by person-to-person spread mainly through the faecal-oral route or, less frequently, by a common vehicle (e.g. contaminated water or food) and multiplies in the intestine, from where it can invade the nervous system and cause paralysis.
It largely affects children under 5 years of age.
The oral polio vaccine (OPV)
contains a live, weakened form of poliovirus
that replicates in the intestine for a limited period, thereby developing immunity by building antibodies.Source : Downtoearth