Massive immunisation could help eradicate polio from India, health experts at United Kingdom's Imperial College London, have said.
The study appearing in the November 17 issue of the journal Science said that vaccination was the key to eradicating polio from countries like India, where the poor sanitation and overcrowding was letting the virus rage unhindered.
Researchers said a newer polio vaccine should be able to overcome these obstacles.
For their study, Nicholas Grassly of Imperial College London and his colleagues analyzed reports of children with paralysis in India, collected since 1997, and used a computer model to determine which conditions most strongly influence the persistence of polio in the country.
They found that poor sanitation and high population density was contributing to the rampant increase of polio cases in Uttar Pradesh and Bihar, two of the states most badly affected by the virus.
"These conditions pack a one-two punch: they make it easier for the poliovirus to spread, and they decrease theefficacy of the vaccine," the authors write in the study.
As such, in place of the standard, 'trivalent' form of the vaccine, which contains weakened versions of each of the three types of poliovirus, the strain-specific 'monovalent' vaccine should compensate for these obstacles and boost the vaccine's efficacy to the point that rapid polio eradication in India should be possible, the researchers say.
"Thequestion from the parents and the government officials in these regions is 'why, with so much vaccination, is polio still around? Our paper shows that we are still seeing polio in India because the conditions there prevent the standard trivalent vaccine from working optimally, but this new vaccine should be able to finish the job," said Grassly.
"Thisstudy makes an important contribution to the discussion about reaching the polio endgame. Time will tell whether the ambitious goal of polio eradication is possible, but these findings should be part of the discussions about the best way forward," added Barbara Jasny, Deputy Editor for Commentary at Science.