Times of India
19 July 2010
By Pratibha Masand
Mumbai, India

Fights 2 deadly strains
This Pulse Polio Sunday, instead of the usual two–drop vaccine, bivalent oral polio vaccine (BOPV) was administered to kids below five years of age. The BOPV was used for the first time in Mumbai. Sixty per cent children were covered in the drive.

This new vaccine, which has been tried in high–prevalence states like Bihar and Uttar Pradesh earlier this year, fights two deadly polio strains–P1 and P3.

Dr Mangala Gomare, who oversees the civic vaccination programme, said the bivalent vaccine is much more effective than the monovalent vaccine.“Every Pulse Polio Drive, we used monovalent vaccine that fights either against the P1 strain or the P3 strain.

But this year, the bivalent vaccine was sent to us, which protects the child from both the strains,” she said.

Earlier, the civic authorities used two types of monovalent vaccines–MOVP1 and MOVP3. While MOVP1 protects against the P1 strain of polio virus that causes large outbreaks and paralyses one out of every 200 children infected, MOPV3, on the other hand, protects against the P3 strain which causes paralysis in one out of every 1,000 infections. Thus, in areas where the vaccine against P1 strain is used, P3 cases go up and viceversa. India reported over 700 fresh cases of polio in 2009. As many as 641 were of P3 infections and the rest were caused by the P1 virus.

For routine immunisation, the child is given the trivalent vaccine, which protects the child against three strains P1, P2 and P3. But the efficacy of trivalent vaccine is not as good as the monovalent vaccine, explains Gomare.“Our target was 12,20,000 children this time, out of which only 60% children were covered,” said Gomare.