Arsh Singh was left paralysed in 2013 when he was just nine months old. A virus took away the mobility in his limbs. His uncle Akhilesh Singh says it was a reporter who informed the family that the toddler had vaccine-derived poliovirus. “The doctors did not bother to tell us,” said Akhilesh Singh, a resident of Navi Mumbai. “The state did not help us. This should have been their responsibility.”

Every month, the family spends around Rs 15,000 on the treatment of the child. Arsh Singh’s father is currently unemployed, and the household is sustained by Akhilesh Singh, a realtor.

The family has been living a cruel irony every day for the past three years. The paralysis that incapacitated Arsh Singh was caused by the oral vaccine that was meant to stave off polio, a highly infectious viral disease that affects young children and can cause paralysis, often permanent.

As doctors explain, the vaccine contains a live, weakened version of the polio virus which mimics the response the immunity system has when it’s actually infected with polio. The vaccine-virus replicates in the intestine and gets excreted for six to eight weeks. There are rare occasions though, when the vaccine-virus genetically mutates during replication – this is called a vaccine-derived poliovirus.

The dangers of the Oral Polio Vaccine have never been unknown. It was adopted in the 1990s, in an ethically controversial decision, over the relatively safer injectable Inactivated Polio Vaccine. While the oral vaccine used a weakened virus, the injectable one used an inactivated one. The injectable vaccine was however more than five times costlier than the oral version.

Oral Polio Vaccine, the argument went at the time, is also easier to administer: health workers, not necessarily trained doctors or nurses, could give the drops easily to children. Besides, for the purpose of polio eradication, the nation needed nearly 100% coverage, which, it was argued, couldn’t be possible with the injectable vaccine. It also causes immunity of the community as the children administered oral vaccine can cross-infect via faecal-oral route with the vaccine virus and naturally immunise others.

Given these evident benefits, the fact that the oral vaccine can cause vaccine-derived poliovirus, leading to paralysis, was disregarded. Finally, the oral version was picked. “As long as we have OPV, we will have VDPV cases,” said Dr Vijay Yewale, former president of the Indian Association of Paediatrics. “Many more children benefit from the programme than not.”

Changes in vaccination programme

Around 20 years on, the World Health Organization declared India “polio free” in 2014, and now, two years after that, the country’s polio vaccination programme is going through a makeover. The Union Health Minister JP Nadda launched an injectable vaccine programme in six states in November 2015 and is taking it across the country. On April 25 this year, India will be one of the 156 countries and territories to take part in a “global switchover”, when the polio vaccination programme will shift from trivalent oral polio vaccine to bivalent oral polio vaccine.

The trivalent oral polio vaccine has three strains of live, weakened polio virus. The bivalent version on the other hand, will have just two strains – it won’t include type 2 wild polio virus, which the WHO says is “no longer needed”. The type 2 polio virus is associated with 90% of vaccine-derived poliovirus.

The switch comes around a time when polio is again trickling into news. Just last month, there were two separate “adverse” incidents related to polio vaccination. In Pampore town in Kashmir, an 18-year-old allegedly spread false rumours about the death of a child after the administration of polio vaccine, causing panic among parents. Across the country, in Odisha, a 21-day-old sickly baby, who was advised to take the drops, died after the administration of the vaccine.

The government has a process to tackle such adverse events, which includes an enquiry by a team at the state level and then at the national level. In Odisha’s Kendrapada district, preliminary reports show the child died of infection and the death had no causal link with the vaccine, said Dr Pradip Haldar, deputy commissioner in the Health Ministry who handles the immunisation programme.

“Polio is one of the safest vaccines,” Dr Haldar said. “It is unknown that somebody dies of the vaccine. We have about 13.5 lakh children under five dying every year, but there is a public perception that the death occurs because of the vaccine.”

While health experts hail the new phase in the polio eradication programme as an improvement, they also lament the price the country’s children had to pay for participating in the controversial programme under WHO-spearheaded Global Polio Eradication Initiative that relied entirely on Oral Polio Vaccine.

“For years children have borne the brunt of the programme and have suffered paralysis,” said Dr Anant Phadke of Jan Swasthya Abhiyaan, a network of civil society groups that work on public health. “The IPV has a distinct advantage of not causing VDVP. So it’s a good thing.”

Even last year, India had two cases of poliovirus cases due to the vaccine. There were three such cases in 2014, and 44 of them in 2009.

Ignoring the warnings

In the 1990s, many experts had opposed the use of oral vaccine because it is not 100% safe.

“As chairman of the India Expert Advisory Group [which monitors and accesses the progress of the programme], I had always been telling everyone that we should have IPV instead of OPV,” said Dr TJ John, former Professor of Christian Medical College, Vellore, and an expert in virology. “We could have saved some funds by using IPV from the beginning. Ethics demands IPV and in fact the whole world uses it. But OPV had its role as without it we would not have ventured to eradicate polio.”

In fact, in 1988, scientist Pushpa Bhargava, founder director of the Centre for Cellular and Molecular Biology who was recently in news for returning his Padma Bhushan, had argued against the use of OPV.

In an opinion piece in The Hindu, he wrote that he was part of a meeting where it was decided to use injectable polio vaccine in India because of the poor efficacy of the oral polio vaccine. A factory to manufacture injectable vaccine was set up in Gurgaon, in Haryana, but was abandoned on the advice of the WHO in 1992. Bhargava claimed that he wrote to various authorities seeking to know what evidence prompted the government to shift to OPV.

Clearly, the government did not share Bhargava’s concerns then. Even today, very often in India, the parents of a child afflicted with vaccine-derived poliovirus are not informed of the source. And nearly always, nobody takes responsibility here, unlike in other nations.

At least 19 counties in the world have a vaccine compensation programme. Germany was the first to enact a compensation programme for vaccine-derived poliovirus in 1961. It was followed by France, then Austria, Denmark, Japan, New Zealand, Sweden and the UK. A similar programme has been set up in the US, Quebec, Italy, Norway, the Republic of Korea, Hungary, Iceland and Slovenia. In UK, the vaccine damage payment is a tax-free one-off payment of 120,000 pounds.

Increasing doses of oral vaccination

While we are free of polio in the strictest sense, it is not that children aren’t suffering from paralysis. As per the National Polio Surveillance data, while the polio cases have become zero (not counting vaccine-derived polio cases), the number of non-polio acute flaccid paralysis cases have increased substantially. Some studies say there’s a link between non-polio AFP and the increasing doses of Oral Polio Vaccine.

Last year, there were 42,804 cases of non-polio AFP, a majority of them in Uttar Pradesh and Bihar. The number of such cases was 59,436 in 2012, and 53,421 and 53,383 in 2013 and 2014, respectively.

Surveillance of acute flaccid paralysis is part of the vaccination programme, so that all cases of paralysis are investigated, and polio can be ruled out. With eradication, all the cases that are falling under the net of surveillance are turning out to be non-polio AFP cases. They could have many causes including autoimmune disorders such as Guillain-Barré syndrome.

In the absence of wild polio transmission, as per WHO standards, there must be an incidence of only one case of non-polio AFP per 1 lakh people. However, nationally, the non-polio AFP rate is 9.82. In the state of Uttar Pradesh the non-polio AFP was 16.11, and in Bihar 25.28 last year.

Non-polio AFP is indistinguishable from polio paralysis cases, but is twice as fatal, as studies show. A delegation from the Public Report on Health from Council for Social Welfare in Delhi found that most of the non-polio AFP cases were not followed up. According to information obtained through the Right to Information Act by Dr Jacob Puliyel, who heads the paediatrics department at St Stephens Hospital in Delhi, of the 10,055 cases of non-polio AFP, only 2,553 were investigated. Of these 2,553 cases, 898 had residual paralysis and 217 children died.

“In the regular polio cases only 1/10th of children suffer from paralysis or death, whereas in non-polio AFP, more than half the children suffer from paralysis or death,” said Dr Puliyel. “This is not a mild disease.”

A study published last year in the American journal Pediatrics said that there is a link between non-polio AFP and the number of OPV doses administered. Another study in the Indian Journal of Medical Ethics in 2012 said that after the polio vaccination programme intensified in 2005, the non-polio AFP cases increased exponentially.

The rise was marked in Uttar Pradesh and Bihar, states where the pulse polio drives would take place almost every month. Only in areas where fewer than six doses were given in a year was the incidence of non-polio AFP low. The number of non-polio AFP cases began reducing in UP and Bihar in 2012, a year after the last polio case was reported in West Bengal and as the two states cut down the oral vaccine doses delivered. The Pediatrics study maintained that the case studies of Bengal of UP are evidence of a causative association between OPV doses and the non-polio AFP rate.

Dr Haldar, however, dismissed these concerns.

“People who say that non-polio AFP is increasing, say that without understanding the programme,” he said. “In 2005, we felt that we may be missing out on a few cases and therefore we decided to make the surveillance of AFP more sensitive to pick any kind of lameness. We decided to pick all kinds of paralysis – not just flaccid where the muscles are loose. When we went to the laboratory for confirmation, only about 25%-30% were reported as polio cases then. So we have higher non-polio AFP cases. In UP and Bihar, where we struggled to implement the programme, we were even more vigilant. That does not mean there is higher AFP.”

But if this explanation is accepted, then one has to assume that there is poor surveillance in Goa and Kerala where non-polio AFP cases were fewer and that the surveillance has now become lower in UP and Bihar since the non-AFP rates are falling, said Dr Puliyel.

“We do not know what is causing non-polio AFP. We are sure that it is not wild polio, one has to ask – Have we replaced polio virus with another paralysis causing virus?” said Dr Puliyel.

This phenomenon needs to be studied, say experts. “It could be a mutation,” said Dr Phadke. “It is something else only, which is not there anywhere else in the world. A sort of scientific enigma. But it is a public health responsibility to find out why.”