What is Poliomyelitis?

This is a distressing infection affecting the spinal nerve that can lead to muscle weakness with resultant permanent weakness of the legs.

What are the available vaccines and their possible problems?

There are 2 vaccines available, namely the weakened live oral (OPV) and killed or inactivated virus (IPV). OPV is given orally. IPV is given as an injection into the muscle in combination with other vaccines such as DTP and Hib.

For the national polio immunisation programme, the government is now using IPV.

The benefits of OPV include intestinal immunity and secondary spread of the vaccine to other children. Thus, OPV offers better protection to the community than IPV in the presence of a possible risk of an imported case of poliomyelitis. However, OPV has been implicated in vaccine-associated paralytic poliomyelitis VAPP when the weakened virus in the vaccine causes the paralysis especially in those with reduced host defenses.

The risk for VAPP is estimated as 1 case per 2.4 million doses of OPV distributed with a first-dose risk of one case in 750,000 first doses distributed.

Which Polio Vaccine should be used?

The WHO is intensifying its effort on the global eradication of poliomyelitis. There are only a handful of countries in Asia and Africa where wild polio virus is still present resulting in poliomyeltis. The decision on which vaccine to use is a complicated issue which involves national immunisation policy and choice by parents using the private service.