Inactivated polio vaccine to end polio

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WHO India National Polio Surveillance Project, New Delhi, as reported by The Hindu.

There is a scientific reason for choosing 14 weeks for IPV immunisation. "When IPV is given to children at 14 weeks and later, nearly 70 per cent of them will develop antibodies against polio viruses. It will be around 30 per cent if given to children younger than 14 weeks", he said.

The switch from OPV with all three strains to only two strains (type 1 and type 3) will happen towards the end of April 2016. "India will make a switch from a trivalent [containing all three virus strains] to a bivalent [containing only two strains] on April 24," Dr. John said.

"There are a risk when this switch is made," he warned. "Vaccine-derived type 2 will spread silently and cannot be stopped and children will continue to shed type 2 strain for 4-6 weeks after the last OPV dose. [A] new crop of children who do not get the trivalent oral polio vaccine can get exposed to [the] type 2 strain shed by vaccinated children," he said.

It is to minimise this that the Global Polio Eradication Initiative requires all countries using the three-strain to introduce at least one dose of the injectable vaccine before making the switch.

"We will be building the immunity of the community against type 2 through IPV and OPV immunisation so that at the time of switching from trivalent to bivalent OPV there will be no risk," said Dr. Pradeep Haldar, Deputy Commissioner – Immunisation, Ministry of Health and Family Welfare, Government of India.

In the initial phase of its launch, IPV will be launched only in the states of Bihar, Chhattisgarh, Gujarat, Madhya Pradesh, Uttar Pradesh and West Bengal.  The launch of IPV has been placed in the order of making it available in the most-affected areas. In the first quarter of 2016, IPV will be introduced in the other Northern and Northeastern States and in the second quarter, will encompass the four southern States and Maharashtra.

IPV also comes loaded with other benefits over the traditional use of OPV. Nearly 60 per cent who receive IPV will develop immunity when compared with/to the 10 to 30 per cent when OPV is used.