Vaccine Derived Polio infection

Context:

A two-year-old child from Meghalaya’s West Garo Hills district reportedly tested positive for polio.

Relevance:

GS II- Health

Dimensions of the Article:

1. What is Vaccine Derived Polio infection?
2. What is Polio?
3. Recent Outbreaks of Polio
4. Polio in India
5. India’s Pulse Polio Programme
6. Steps taken by the Government to maintain polio free status in India

What is Vaccine Derived Polio infection?

• A vaccine-derived poliovirus is a strain related to the weakened version of the live poliovirus contained in the oral polio vaccine (OPV) and become neurovirulent (able to cause paralysis and circulate in communities).
• The neurovirulent virus is referred to as vaccine-derived poliovirus (VDPV).
• This is a very rare event. In the 10 years leading up to 2015 there were around 750 cases of paralysis caused by VDPVs reported worldwide.

What is Polio?

• The World Health Organization (WHO) defines polio or poliomyelitis as “a highly infectious viral disease, which mainly affects young children.”
• 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 can cause paralysis.
• Initial symptoms of polio include fever, fatigue, headache, vomiting, stiffness in the neck, and pain in the limbs.
• In a small proportion of cases, the disease causes paralysis, which is often permanent.
• There is no cure for polio, it can only be prevented by immunization.
• There are three individual and immunologically distinct wild poliovirus strains:
  1. Wild Poliovirus type 1 (WPV1)
  2. Wild Poliovirus type 2 (WPV2)
  3. 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.

Recent Outbreaks of Polio

• In 2019, polio outbreaks were recorded in the Philippines, Malaysia, Ghana, Myanmar, China, Cameroon, Indonesia and Iran, which were mostly vaccine-derived in which a rare strain of the virus genetically mutated from the strain in the vaccine.
• Afghanistan and Pakistan are the two countries that are having the most trouble in controlling the spread of Polio effectively.
• In 2018, a total of 8,60,000 children in Afghanistan did not receive polio vaccine due to security threats.

Polio in India

• India received polio-free certification by the WHO in 2014, after three years of zero cases.
• This achievement has been spurred by the successful pulse polio campaign in which all children were administered polio drops.
• The last case due to wild poliovirus in the country was detected on 13th January 2011.

India’s Pulse Polio Programme

• With the global initiative of eradication of polio in 1988 following World Health Assembly resolution in 1988, Pulse Polio Immunization programme was launched in India in 1995. Children in the age group of 0-5 years administered polio drops during National and Sub-national immunization rounds (in high-risk areas) every year.
• The Pulse Polio Initiative was started with an objective of achieving hundred per cent coverage under Oral Polio Vaccine.
• It aimed to immunize children through improved social mobilization, plan mop-up operations in areas where poliovirus has almost disappeared and maintain high level of morale among the public.

Steps taken by the Government to maintain polio free status in India

• Maintaining community immunity through high quality National and Sub National polio rounds each year.
• An extremely high level of vigilance through surveillance across the country for any importation or circulation of poliovirus and VDPV is being maintained.
• All States and Union Territories in the country have developed a Rapid Response Team (RRT) to respond to any polio outbreak in the country.
• To reduce risk of importation from neighbouring countries, international border vaccination is being provided through continuous vaccination teams (CVT) to all eligible children round the clock.
• Government of India has issued guidelines for mandatory requirement of polio vaccination to all international travelers before their departure from India to polio affected countries namely:  Afghanistan, Nigeria, Pakistan, Ethiopia, Kenya, Somalia, Syria and Cameroon.

-Source: The Hindu, The Indian Express