7 PM | Cutting risk: On India’s anti-polio drive | 26th October, 2019

Context:Declaration of global eradication of wild poliovirus type 3.

More in news:

• World Polio Day is celebrated on 24 October annually to raise awareness about the polio disease and efforts for eradication.
• Global eradication of wild poliovirus type 3 declared on World Polio Day

Polio:

• Poliomyelitis (polio) is a highly infectious viral disease, which mainly affects young children (under 5 years of age).
• 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 inter the nervous system and can cause paralysis.
• Initial symptoms are fever, fatigue, headache, vomiting, stiffness of the neck and pain in the limbs.
• 1 in 200 infections leads to irreversible paralysis (usually in the legs).
• Among those paralyzed, 5% to 10% die when their breathing muscles become nonfunctional.
• There is no cure for polio, it can only be prevented. Polio vaccine, given multiple times, can protect a child for life.
• The strategy to eradicate polio is therefore based on preventing infection by immunizing every child until transmission stops and the world is polio-free.
• There are two types of vaccine to prevention infection.
  • OPV (Oral Polio Vaccine): It is given orally as birth dose for institutional deliveries, then primary three doses at 6, 10 & 14 weeks and one booster dose at 16-24 months of age.
  • Injectable Polio Vaccine (IPV): It is introduced as an additional dose along with 3rd dose of DPT under universal immunization programme (UIP).

Global Polio Eradication Initiative:

• In 1988, the Forty-first World Health Assembly adopted a resolution for the worldwide eradication of polio.
• It marked the launch of the Global Polio Eradication Initiative (GPEI).
• The Global Polio Eradication Initiative is a public-private partnership led by national governments with five partners: the World Health Organization (WHO), Rotary International, the US Centers for Disease Control and Prevention (CDC), the United Nations Children’s Fund (UNICEF) and the Bill & Melinda Gates Foundation.
• The goal of the Global Polio Eradication Initiative is to complete the eradication and containment of all wild, vaccine-related and Sabin polioviruses, such that no child ever again suffers paralytic poliomyelitis.

World Polio Day 2019:

• In an historic announcement on World Polio Day, an independent commission of experts concluded that wild poliovirus type 3 (WPV3) has been eradicated worldwide.
• Following the eradication of smallpox and wild poliovirus type 2, this news represents a historic achievement for humanity.
• There are three individual and immunologically-distinct wild poliovirus strains: wild poliovirus type 1 (WPV1), wild poliovirus type 2 (WPV2) and wild poliovirus type 3 (WPV3).
• WPV3 is the second strain of the poliovirus to be wiped out, following the certification of the eradication of WPV2 in 2015, with the last virus detected in India in 1999.
• The last case of WPV3 was detected in northern Nigeria in 2012. Since then, the strength and reach of the eradication programme’s global surveillance system has been critical to verify that this strain is truly gone. 
• Wild poliovirus type 1 remains in circulation in just two countries: Afghanistan and Pakistan.
• As on October 23, there were 18 cases of polio caused by wild virus type 1 in Afghanistan and 76 polio cases in Pakistan this year.

Polio free India: India marks six years since last polio case

• India received polio-free certification along with the entire South-East Asia Region of WHO on 27th March 2014, three years after the last case of wild poliovirus infection, detected in the West Bengal India. 
• January 2017 marks six years since the last case of polio was reported in India.
• India accounted for nearly half of all cases of polio in the world till as recently as 2009, and was considered one of the most difficult places in the world to eradicate Polio.
• This milestone demonstrates the importance of strong surveillance systems, intensive vaccination drive and targeted social mobilization efforts.
• But until the disease is eradicated, India must remain vigilant. That’s why on National Immunization Days children are vaccinated across the country to maintain high levels of childhood immunity.

Vaccine Derived Polio Virus (VDPV) in India:

• Though, India is a wild, poliovirus, disease-free country currently. But, the cases of Vaccine Derived Polio Virus (VDPV) disease, (around 50 cases documented by India lauded AFP surveillance system) can be seen.
• The emergence of VDPV disease is a known risk of OPV vaccination, where the weakened live virus given as vaccine in OPV start becoming virulent and thus give rise to the disease in a few children among the lakhs that were vaccinated with it. 
• There are two types of vaccinations that work against poliovirus, namely inactivated poliovirus (IPV) and oral poliovirus (OPV).
• The injectable inactivated poliovirus vaccine (IPV) protects almost all children (99 out of 100) who get all the recommended doses.
• The oral OPV is given in UIP (Universal Immunization Programme) of India, offers somewhat low protection for an Individual (~90 percent) but much better protection for the whole community, due to its gut immunity profile.

Way Forward:

There is a dire need to focus on getting more and more children vaccinated with IPV, which not only poses no risk of VDPV but also give 99 percent protection from wild polio and VDPV disease.

Source:https://www.thehindu.com/opinion/editorial/cutting-risk-on-indias-anti-polio-drive/article29801622.ece