The bivalent vaccine (bOPV) is being introduced in the country for the first time in Bihar from tomorrow which is National Immunization Day (NID) for pulse polio campaign. President Pratibha Devisingh Patil launched the NID by administering polio drops to ten babies at Rashtrapati Bhawan in Delhi today.

Speaking on the occasion the Union Minister of Health and Family Welfare Ghulam Nabi Azad said that the bivalent vaccine will also be introduced in Uttar Pradesh from next round. About 25 lakh kids will get the new drops. Overall 170 million kids are likely to be immunized in this round of NID.
 
 There are three strains of wild polio virus, viz P1, P2 & P3. Type 2 wild polio virus (P2) has been eliminated in the year 1999. Efforts are being made to eradicate P1 and P3 also. As P1 is the more virulent type of the two, the current strategy is to eliminate it first while keeping P3 under control. Once P1 is eradicated, efforts to eradicate P3 will be made. Initially trivalent Oral Polio Vaccine (which caters to all the three strains of wild polio virus) was used in the campaign.

Subsequently, more efficacious monovalent vaccine was introduced in the programme to handle the type 1 and type3 wild polio virus. While the monovalent vaccine has been found to be effective in containing the transmission of P1, it has affected the control of transmission of P3 getting compromised. Recently a bivalent vaccine has been developed which will control P1 and P3 simultaneously. This vaccine is being introduced from tomorrow.
 
Pulse polio programme was started in the year 1995 with the objective to eradicate poliomyelitis. Prior to starting the campaign, the number of paralytic cases due to polio was in the range of approximately 50000 every year. A drive against wild polio virus by organizing pulse polio campaign has seen a drastic reduction in the number of paralytic cases due to polio and it has been limited to a few hundreds now.
 
33 States/UTs are now free of indigenous transmission of wild polio virus. Only UP and Bihar remain the two endemic States in the country for wild polio virus where the indigenous transmission is still continuing. A multi pronged approach is being adopted where on the one hand efforts are being made to vaccinate each and every child with Oral Polio Vaccine (OPV) and on the other, efforts to ensure sanitation, hygiene and clean drinking water are being ensured.
 
For the year 2009, 721 cases have been reported so far. Out of these, 641 are wild poliovirus type 3 (WPV3) & 79 are wild poliovirus type 1 (WPV1) & one case is a mixture of both i.e. WPV1 + WPV3.