A major milestone in polio eradication

Today, India passes one whole year without polio caused by natural (wild) poliovirus — a major milestone towards polio eradication. This spells relief from an agonising decade of wild polioviruses refusing to surrender. Many experts believed that India posed the greatest challenge to polio eradication for epidemiological reasons; our success proves it can be achieved in other countries where the obstacles are more programmatic than biological. For the Global Polio Eradication Initiative (GPEI), this is a shot in the arm.

THE DECADE OF AGONY

The year 2000 was the target date for global eradication set by the World Health Assembly in 1988. Intense efforts by countries, guided by GPEI, resulted in success in most countries and partial success in all countries. Of the 3 types of polioviruses, type 2 was globally eradicated in 1999 — with the last case in Uttar Pradesh. But transmission of types 1 and 3 continued in six countries. Later, two more succeeded, leaving India, Pakistan, Afghanistan and Nigeria with continuing transmission beyond 2005. In India, during the last decade, over 95 per cent of cases occurred in U.P. and Bihar — arguably the world's most difficult spots for eradication. In 2000 and 2001, there were 265 and 268 cases but in 2002 an outbreak occurred with 1600 cases, mostly type 1. Then, the numbers dwindled to 225 and 134 in 2003 and 2004, and 66 in 2005. All hopes of success were shattered by another polio outbreak in 2006, with 648 cases of type 1 and 28 of type 3 polio.

Since type 1 showed a cyclical nature of outbreaks every fourth year — 1998, 2002 and 2006 — the next outbreak in 2010 had to be averted at all costs. Type 2 had taught us that sequential eradication of one type at a time was realistic. So type 1 was targeted and the tactics paid off — we had less than 100 cases each during 2007-2009, 18 in 2010 and just one case on January 13, 2011 — none since.

Type 3 cases were less than 10 in 2004 and 2005. Unfortunately, while type 1 was singled out for attack, type 3 outbreaks developed, first in Bihar (2007-08) and then in U.P. (2008-09). So in 2010, there was yet another change of tactic, now focussing on type 3 along with type 1. There were 24 cases of type 3 in 2010 and none in 2011. In U.P., the last wild virus polio was reported on April 21, 2010 and in Bihar on September 1, 2010 — both type 3. So we have now come 20 months without a case in U.P. and 15 months in Bihar. The case of January 13, 2011, was reported not from U.P. or Bihar, but from Howrah in West Bengal.

PROBLEMS & INNOVATIVE SOLUTIONS

By 1988, nearly 70 countries had achieved the elimination of wild poliovirus transmission through their routine national immunisation programmes, some using the inactivated poliovirus vaccine (IPV) but others using the oral poliovirus vaccine (OPV). For countries with polio, the World Health Organisation recommended the exclusive use of OPV for its low cost and ease of inoculation by mouth — as two drops. On the flip side, the very fact that many countries using OPV could not control polio with routine immunisation indicated that it was not as effective as in other countries. The difference was clear: tropical/ subtropical countries with low income, overcrowding, high birth rates, and high child mortality faced low effectiveness of OPV, whereas those with the opposites had high vaccine effectiveness.

In India, the disparities of such factors spelt differential effectiveness among States. Not only did some communities exhibit lower vaccine effectiveness, they also had more intense wild virus transmission. The conjunction of both problems made U.P. and Bihar stand out as the most difficult regions for polio eradication. Indian scientists had actually warned the GPEI of such pitfalls but global leaders from rich countries couldn't believe that such extreme variations could exist with wild virus epidemiology and vaccine effectiveness. Once that lesson was learned, the progress was rapid.

Wild polioviruses exist in 3 types, and OPV also contains attenuated strains of the 3 types. So it is called trivalent OPV (tOPV). Among the 3 types, type 2 is the most efficient; that was why type 2 wild virus disappeared in 1999, within a few years of national pulse vaccinations. But type 2 in the tOPV also interferes with the others, making them very inefficient. From 2000, the frequency of campaigns with tOPV was increased in U.P. and Bihar, but to no avail. Type 2 had to be removed from tOPV to get the best out of types 1 and 3. In 2005 and thereafter, a new monovalent type 1 OPV (mOPV-1) was used in U.P. and Bihar — it is three times more effective than tOPV. This was one factor of success. But gaps in immunity were created against type 3; consequently, type 3 outbreaks occurred in 2007-2009. Then, a bivalent vaccine (bOPV with 1 and 3) was developed. It was non-inferior to mOPV-1 or mOPV-3. From early 2010, bOPV has been widely used in U.P. and Bihar during campaigns, while tOPV is used everywhere for routine immunisation.

While the problem of “failure of vaccine” was being addressed, there was also the problem of “failure to vaccinate”. Seasonally, millions of families from U.P. and Bihar migrate for work — some to Maharashtra or Punjab, others within their States. Their children missed both routine and campaign doses. The tactic of vaccination in transit — in trains/buses and in stone quarries/brick kilns — became the norm from 2005. As all bottlenecks were cleared, success ensued.

TRIBUTE TO THE NATION

Many global experts marvel at the ability of Indians to work with diligence and sincerity, and at India's tenacity in spite of pessimistic prophecies of failure. So a tribute is due: to the families of children and all workers, district managers — medical and administrative — State leadership, the National Polio Surveillance Project personnel, the Government of India staff working alongside the global polio partners, WHO, UNICEF, Rotary International and the U.S. Centres for Disease Control, and the vaccine manufacturers who up-scaled production on demand, and filled the prescriptions for mOPV-1 and 3 and for bOPV. All of them deserve our applause and gratitude.

In many other programmes in India, poor implementation is the oft-repeated reason for failures and delays. The success of implementation depends on the design of the programme and proper supervision of activities. The government must learn and apply this lesson in all other faltering health projects — against TB, malaria, child mortality and under-nutrition.

WHAT NEXT?

For certification of eradication, two more years should pass without any case of wild virus polio. Poliovirus can remain silently in circulation for short periods; so, complacency must not set in. We must continue working as if we still have poliovirus lurking somewhere, only to show up when least expected. There is also the threat of importation of wild virus from Pakistan, Afghanistan and Nigeria.

Vaccine viruses by themselves can rarely cause polio; the balance is roughly one case of vaccine-associated paralytic polio (VAPP) replacing 200 cases of wild virus polio. Yet, in the absence of wild virus polio, VAPP is unacceptable. Moreover, vaccine viruses may gradually revert to wild-like properties if allowed to circulate. Such circulating vaccine-derived polioviruses (cVDPV) cropped up in many OPV-using countries recently, including India since 2009. If allowed to grow, they can capture the niche vacated by wild viruses. We have to stop OPV to stop VAPP, but some cVDPV may already be in silent circulation to show up in outbreaks one or more years later. The safest solution is to introduce IPV, reach 90 per cent or more coverage and only then stop OPV. That will pre-empt the evolution of cVDPVs. Only after we ensure the absence of wild and vaccine polioviruses in the population can we claim complete success of polio eradication. That is the challenge of the present decade.

(The author was professor of clinical virology in the Christian Medical College, Vellore until retirement, and has served on several Global and National Committees on Immunisation and Polio Eradication.)

No new wild polio case for a year, India beats down deadly virus

Not even superstition can render this Friday the 13th unlucky for India. Today, the nation will reach a major milestone in the history of polio eradication – a year without any case of wild polio being recorded. For a nation that notoriously had, only two years ago, the largest number of polio cases in the world (741), this is clearly an unprecedented achievement.

Poliomyelitis (polio) is a highly infectious viral disease which mainly affects young children. The virus is transmitted through contaminated food and water, and multiplies in the intestine, from where it can invade the nervous system. Even those who do not show any symptoms can excrete the virus, thereby spreading the infection. Acute Flaccid Paralysis is a disabling condition where there is absence of muscle tone in one or both limbs, and tendon reflexes. While no ‘cure' exists for polio, the oral polio vaccine prevents the transmission of infection effectively.

As India reaches this ‘no wild case' mark, it will no longer be considered ‘endemic' to polio, a status it has harboured thus long, with three other nations — Pakistan, Afghanistan and Nigeria. If all tests for the wild polio virus in India — including laboratory analysis of acute flaccid paralysis cases with onset up to mid-January and environmental sewage sampling — return negative, India will officially be deemed to have stopped the transmission of the indigenous wild polio virus.

Following this, the World Health Organisation will remove India from the list of endemic nations, probably by mid-February. “India's success is arguably its greatest public health achievement and has provided a global opportunity to push for the end of polio,” said WHO Director-General Margaret Chan.

Responding to the achievement, Union Health Minister Ghulam Nabi Azad said: “This giant leap towards polio containment in a short span of two years is an endorsement of India's tireless and persistent efforts.” India had set an example with the highest level of political commitment to the programme — with resource allocation, continuous efforts to identify and reach out to vulnerable children with tailored strategies for maximum reach, optimum use of available vaccines under the guidance of top national and international experts, an extra-ordinary communication strategy and strong partnerships, he added.

According to the Global Polio Eradication Initiative (GPEI), the next step would be to look at a polio-free South East Asian Region in 2014: Over the next 24 months, the Regional Certification Commission of the WHO South East Asian Region (of which India is a part) will start examining the surveillance and programme performance for polio eradication across the region to determine whether it can be certified as having eradicated the indigenous wild poliovirus.

Food as people's right

This is the season to count blessings. India's greatest blessings are its adherence to the democratic system of governance, an independent judiciary, a free and fearless media, and an Election Commission that inspires confidence. I hope that soon India will have an independent and effective Lokpal, which will pave the way for a corruption-free India, a pre-requisite for a hunger-free India.

The other major paradigm shift observed in recent years is the substitution of political patronage with legal rights. Thus, a few years ago, the United Progressive Alliance government, then supported by the Left parties, enacted legislation designed to confer entitlements to information, education and work, in the third case the Mahatma Gandhi National Rural Employment Guarantee Scheme. Tribal families and other forest-dwellers have been conferred the right to land. The brightest jewel in the crown of Indian democracy will be the conferment of the right to food through the National Food Security Act, recently introduced in Parliament. When it is implemented, this country will have taken the essential steps necessary to convert Gandhiji's dream of a hunger-free India into reality.

It is important to realise the significance of the Act in the light of the conditions that prevailed in India during the first 20 years after Independence. During the 1960s, India was the largest importer of food aid, mainly under the PL480 programme of the U.S. In fact, during 1966, over 10 million tonnes of wheat was imported, leading to India being labelled as a nation surviving on a ship-to-mouth basis. Today, India is set to commit over 60 million tonnes of home-grown wheat, rice and nutri-millets to fulfil the legal entitlements under the Food Security Act. When it becomes law, India will operate the largest social protection programme against hunger in human history. How did this transition occur? Here is the historical context in which we should view the Act.

ROLE OF GREEN REVOLUTION

The Bengal Famine of 1942-43, which claimed over two million lives, provided the backdrop to India's Independence in 1947. The country's population was then a little over 300 million, that is, 25 per cent of the current population. In 1947, not more than 30 persons could be fed at a wedding; today money is the only limit to the number of people who can be entertained on such occasions. Prime Minister Lal Bahadur Shastri even issued an appeal that every Indian should fast one day a week in order to enable the government to balance the food budget.

In 1947, our soils were both thirsty and hungry, and to quote Aristotle, “soil is the stomach of the plant.” Hardly 10 per cent of the cultivated area had assured irrigation, and the average consumption of NPK nutrients was less than 1 kg a hectare. The average yield of wheat and rice was about 800 kg per ha. Mineral fertilizers were mostly applied to plantation crops; food crops got whatever organic manure farmers could mobilise. During the first two Five Year Plans (1950-60), emphasis was placed on enlarging the area under irrigation and on fertilizer production. Scientists began extensive experiments in the 1950s to assess the response of rice and wheat varieties to fertilizer application. The varieties cultivated had tall and thin straw and the crop lodged when even small quantities of nutrients were applied. It became clear that varieties with short and stiff straw were needed to get positive response from water and fertilizer.

It is in this background that Dr. K. Ramiah, an eminent rice scientist, suggested in 1950 that we cross the japonica varieties of rice obtained from Japan with our indica rice varieties. The logic was that the japonica varieties were even then yielding over five tonnes a ha, while Indian varieties gave one tonne to two tonnes a ha. Thus began the indica-japonica rice hybridisation programme at the Central Rice Research Institute in Cuttack in the early 1950s. The programme lost its priority after genes to develop semi-dwarf varieties of rice became available in the 1960s from Taiwan and the International Rice Research Institute in the Philippines.

After the Second World War, American scientists were examining the significant findings made in Japan both in agriculture and industry. Solomon, a biological scientist, was fascinated by the semi-dwarf wheat varieties developed by Dr. Gonziro Inazuka at the Norin Experiment Station. This variety had short and stiff straw but long panicles, and consequently a high-yield potential. Dr. Solomon gave seeds of the Norin wheat variety to Orville Vogel of Washington State University, who developed the semi-dwarf winter wheat variety Gaines, with a yield potential of over 10 tonnes a ha. Norman Borlaug, working in Mexico, obtained the seeds containing the Norin dwarfing gene from Dr. Vogel and started the Mexican dwarf wheat breeding programme. Winter wheats like Gaines do not do well under Indian conditions.

On the other hand, Dr. Borlaug's material was suited for the rabi season in India. I therefore approached Dr. Borlaug in 1959 for some of his semi-dwarf wheat breeding material. Dr. Borlaug wanted to see Indian growing conditions before making up a set of breeding lines, and paid a visit in March 1963. We tested the material at locations all over North India during rabi 1963. The multi-location trials revealed that the semi-dwarf wheats of Mexican origin could yield four to five tonne a ha, in contrast to about two tonnes a ha of the tall Indian varieties. It became clear that India had the tools with which to shape its agricultural destiny.

In July 1964, C. Subramanian became Union Minister for Food and Agriculture and he gave his whole-hearted support to spreading high-yielding varieties on a large scale, together with irrigation water and mineral fertilizer. In 1968, Indian farmers harvested about 17 million tonnes of wheat; the earlier highest harvest was about 12 million tonnes in 1964. Such a quantum jump in production and productivity led Indira Gandhi to announce the ‘Wheat Revolution' in July 1968.

In addition to the yield breakthrough in wheat and rice, hybrids of maize, jowar and bajra developed by Indian scientists in partnership with the Rockefeller Foundation, opened up opportunities to increase productivity and production of the crops. This led to the introduction by the Government of India in 1967 a High-yielding Varieties Programme in wheat, rice, maize, jowar and bajra. For the first time, yield consciousness was born in farmers' minds and they organised a National Tonnage Club of Farmers. The membership eligibility criterion was the production of an agreed minimum quantity of foodgrains per ha. The term Green Revolution coined by William Gaud of the U.S. in 1968, involved synergy among technology, services, public policies and farmers' enthusiasm. Farmers, particularly those in Punjab, converted a small government programme into a mass movement.

The Green Revolution was criticised by social activists on the ground that the high-yield technology involving the use of mineral fertilizers and chemical pesticides is environmentally harmful. Similarly, some economists felt that the new technologies would bypass small and marginal farmers, for although the technologies are scale-neutral, they are not resource-neutral. This led to my coining the term “ever-green revolution,” to emphasise the need to enhance productivity in perpetuity without ecological harm.

UNTAPPED RESERVOIR

Looking ahead, the bright spot in Indian agriculture is the availability of a large untapped production reservoir. For example, the productivity of foodgrains in China is currently 5,332 kg a ha, while it is 1,909 kg a ha in India. A “bridge the yield gap” movement is needed. The dark spots in Indian agriculture relate to ecology and economics. The heartland of the Green Revolution, comprising Punjab, Haryana and Western Uttar Pradesh, is in an ecological crisis, as a result of the over-exploitation of groundwater and the spread of salinity. This region will also suffer most if the mean temperature rises by 1 degree to 2 degrees C as a result of global warming. Conservation and climate-resilient farming will help check ecological hazards. The Food Security Act will confer double benefits – procurement at a remunerative price for the public distribution system will stimulate production, and consumers who need social support to ward off hunger will be able to have economic access to the food needed for a productive life.

One of India's major blessings is the rich store of experience and knowledge available in the rural and tribal areas. The Food and Agriculture Organisation (FAO) recently recognised the Traditional Agriculture System of Koraput, Odisha, as a Globally Important Agricultural Heritage System. This is because the system provides an outstanding contribution to promoting food security, biodiversity, indigenous knowledge and cultural diversity for sustainable and equitable development. The future of food security will depend on a combination of the ecological prudence of the past and the technological advances of today.