A new study found underlying assumptions of India’s Polio program faulty and has recommended that the nation revamp its immunization program especially in Uttar Pradesh and Bihar where suspicion, illiteracy, and weak-implementation persist.
The study published in the journal Science, challenged the three fundamental assumptions driving Indian polio vaccination program. The anti-polio drive believes that three doses of the oral vaccine is sufficient to protect children from polio, a weakened viral strain will automatically spread to and protect other children not immunized, and that the oral vaccine will imbibe strong immunity. An analysis of this article carried in The Hindu cited Jacob John, a veteran of Indian polio eradication effort and formerly with the Christian Medical College at Vellore, published papers as early as in mid-1970s showing that the response of Indian children to vaccine is lower than those from the US .
The recent study in Science confirms John’s assertion and blames it on high population density and poor sanitation as main culprits that are minimizing the effects of the oral vaccine as the virus continues to be entrenched. While polio eradication has been largely successful in reducing incidence from 35,000 children in 1995 to 66 in 2005, it has not managed to eradicate the virus or the causal factors. Further, the 80% increase in polio incidence this year, largely from Muslim populations in Uttar Pradesh, to 540 has raised attention levels to this dangerous affliction.
Researchers say that UP and Bihar records say that children less than 5 had 15 doses of oral vaccine but only 4% of children, mostly babies less than 6 months, received less than 3 doses. If the data reported by these States to be true, then the level of coverage for this virus will be complete even in the most extreme conditions. The credibility of data is an assumption that the study makes which is questionable—after all, there are numerous incidences of data doctoring by schools, food programs, employment programs, and social programs to justify expenditure or show success. Therefore, the assumption that these children were given vaccine as reported by these States with inbuilt corrupt administrations is not well founded.
The researchers from Imperial College in London, National Polio Surveillance Project in Delhi , Enterovirus Research Centre in Mumbai, and WHO's Global Polio Eradication Initiative found high correlation of high population density and diarrhea and routine low oral vaccine use. Coincidentally, the districts with such conditions were in UP and Bihar explaining the low efficacy rate on children in UP at 9% and Bihar 18% compared to a national average of 21% and 65% in industrialized nations.
Further, the researchers also found that the use of “trivalent” cocktail to deal with three prominent strains of polio was less effective as against a “monovalent” vaccine. They recommended that movalent oral vaccine for type 1 and type 2 strains be administered individually which they found three times more effective in preliminary tests. The study claims that the use of movalent in high-risk districts of UP, Bihar, and Mumbai arrested a massive spread of epidemic. John laments that the medical community already knew that the trivalent vaccine was not effective for the last 3 decades but policy makers and administrators refused to re-evaluate the program.
The study also revealed administrative gaps in UP. While routine immunizations were stopped because of opposition by Muslims fearing a conspiracy against them, they also fudged data by administering polio vaccine to older children to show numbers.
Thankfully, the increased attention from the Indian Expert Advisory Group that monitors the progress of the program has helped. Since 2 does of syringe borne vaccine can provide 99% protection against the virus, this group has ordered a change to this method in Moradabad and J.P. Nagar districts in UP.