WHO declares India polio-free

 

NEW DELHI, March 27 (Thomson Reuters Foundation): The World Health Organisation declared India free of the crippling polio virus on Thursday, making the country’s almost two-decade-long, multi-billion-dollar effort one of the biggest public health achievements in recent times.
India’s last case of the wild polio virus was detected in January 2011 in a two-year-old girl in the state of West Bengal. Three years without any new cases means a country can be certified as polio-free.

Afghanistan, Pakistan and Nigeria are the only countries in the world left where the virus remains endemic, largely due to violent conflicts, weak health systems and poor sanitation.

“This ceremony ... marks one of the biggest public health achievements,” Poonam Khetrapal Singh, the WHO’s Southeast Asia director, told diplomats and health officials at the event.

“It is a day that all countries fought hard for, and a day when all stakeholders come together to celebrate the victory of mankind over a dreaded disease that, for centuries, has killed and disabled legions.”

Until the 1950s, polio crippled thousands every year in rich countries. It attacks the nervous system and can cause irreversible paralysis within hours of infection.
The highly contagious virus often spreads in areas with poor sanitation and children under five are the most vulnerable.
In 1988, the Global Polio Eradication Initiative - led by governments and supported by organisations such as WHO, Rotary International and the U.N. Children’s Fund - was launched to ensure comprehensive, nationwide vaccination in endemic nations.

More than 350,000 children across 125 countries were being paralysed or killed by polio every year at that time. That figure has since reduced by 99.9 percent and in 2013, just 406 cases of polio were reported.

India - where more than 50,000 children were afflicted with the virus every year - was considered one of the toughest places in the world to eradicate polio. Many families in poor, high-risk northern states such as Bihar and Uttar Pradesh migrate for work, while others live in remote areas.

Millions of health workers were involved in India’s mammoth drive to immunise children by giving them polio drops.
They targeted migrant families at bus stations, on trains and at festivals. Some used motorcycles or trekked by foot to reach villages.

As a result, over 170 million children are now immunised every year, with millions more targeted in house-to-house visits in a drive which has cost the government $3 billion since 1995.

In 2009, 741 Indians fell sick with polio, nearly half the world’s cases that year. The number dropped to 42 in 2010 and only one in 2011.

In Pakistan - the only country where polio cases are increasing - gunmen frequently attack polio workers, accusing them of being Western spies and part of a plot to sterilise Muslims. Earlier this month, militants killed 12 members of the security escort for a polio vaccination, detonating a roadside bomb before opening fire on their convoy.
In neighbouring Afghanistan, a three-year-old girl was found in February to have contracted the first case of polio in the country’s capital Kabul since 2001.

 

New Delhi, March 27 (agencies): For India, which has successfully kept naturally-occurring ‘wild’ polioviruses at bay for three whole years, a new challenge looms. India is among 140 countries that rely on the oral polio vaccine (OPV). These countries have now been asked to introduce an injectable inactivated polio vaccine (IPV) into their routine childhood immunisation programme by the end of next year.

The oral vaccine, which is cheap and easily administered, uses live but weakened forms of the poliovirus. But the live vaccine viruses can occasionally revert to virulence. Vaccine-derived viruses can gain the ability to transmit within communities and even pass from one country to another. Such ‘circulating vaccine-derived polioviruses’ (cVDPV) have struck over 700 children since the year 2000, producing outbreaks in several countries, including Pakistan, Afghanistan, Nigeria and Somalia.

More than 95% of the cVPDV cases in recent years have been of the type 2 strain (the poliovirus has three strains, types 1, 2 and 3). Polio caused by a wild type 2 virus was, on the other hand, last seen 15 years back. The Global Polio Eradication Initiative (GPEI), which coordinates the global fight again polio, therefore wants to stop all use of OPV that contains the type 2 vaccine strain. Trivalent OPV, with all three types of vaccine strains, is to be replaced by bivalent OPV with only type 1 and type 3 vaccine strains.
But before making that switch, the GPEI has asked all countries using trivalent OPV to introduce at least one dose of the injectable IPV vaccine into their routine immunisation programme. IPV, which is more expensive, uses killed forms of the three types of wild viruses and carries no risk of reversion to virulence. This vaccine would provide protection against any type 2 vaccine-derived viruses lingering in the environment.

Trials carried out with IPV in Tamil Nadu around the 1980s by veteran virologist T. Jacob John and his colleagues at the Christian Medical College at Vellore had found that the injectable vaccine was very effective against the poliovirus in an Indian context. An independent effort that tested IPV in Mumbai slums came to the same conclusion.
If IPV had been introduced in India’s routine immunisation programme and OPV used in mass campaigns, “we could have eliminated polio decades ago,” writes Dr. Jacob John in an article appearing in the Economic & Political Weekly next month. A multi-centre study under way in the country is examining the immunity that would be provided when bivalent OPV and IPV are employed in routine childhood immunisation.

But for IPV to be effectively deployed, routine immunisation coverage has to be improved. According to the National Family Health Survey of 2005-06, while over 80% of children in Tamil Nadu had received all basic vaccinations, only 23% of those in Uttar Pradesh and 33% in Bihar were similarly covered. Lessons from India’s success in polio eradication are being used to enhance routine immunisation and reach under-served communities.