The Centre’s gamble to introduce bivalent oral polio (BOPV) vaccines in high-risk states this year seems to have worked well. Polio cases in India have come down to their lowest in the last decade, indicating the virus is responding to the vaccine programme. Only 24 cases have been detected between January and June, compared to 151 in the corresponding period last year, and 317 in January-June 2008.
The delayed monsoon seems to have worked to the advantage of the government, which received a lot of flak last year after the total number of cases reached 741, almost 200 more than 2008. This year, the health ministry has pulled up its socks with a better campaign, immunisation coverage, and a new vaccine. The extent of its success will be known only after the rains.
“We were never so optimistic. The new vaccine has worked well so far as it is effective on both P1 and P3 forms, compared to the oral polio vaccine (OPV), which helped to keep only P1 low, but was not very effective on P3,” said Dr Naveen Thacker, an expert on the government’s polio advisory panel.
There is guarded optimism in the health ministry. Officials are keeping their fingers crossed as the number of polio cases usually shoot up during monsoon. “So far, the trend shows that the virus is under check. But it is too early to celebrate as between July and August, the number of cases usually shoot up; moist weather is better suited for the virus,” said a senior health ministry official.
Of the cases detected this year, six are of P1 and 18 of P3; P1 is more virulent than P3.
Maharashtra (Nashik), Jammu & Kashmir (Jammu) and Uttar Pradesh have each reported one case of P1, and West Bengal three. Most P3 cases have been found in Uttar Pradesh and Bihar. Globally, 501 polio cases have been detected this year in 16 countries. In India, 16 districts are in the grip of the virus.