Although most infections with poliovirus manifest as asymptomatic or non-specific febrile illnesses, the infection may lead to paralytic disease or death as a result of damage to lover motor neurons.
Two types of vaccine are available, both of which are trivalent formulations containing types 1, 2 and 3 poliovirus: the inactivated poliovirus vaccine (IPV) which is administered by injection and the live, attenuated oral poliovirus vaccine (OPV). Both vaccines prevent paralytic disease in over 95% of recipients.
- ADVERSE REACTIONS
No serious side effects of currently available IPV have been documented.
- MATERIAL RISKS
Because IPV contains trace amounts of streptomycin and neomycin, systemic allergic reactions in individuals sensitive to these antibiotics are possible, but are extremely rare.
The use of OPV has been associated with paralytic disease in both recipients of the vaccine and in their contacts. The risk of such disease is significantly increased in infants with severe immunodeficiency disorders. However, in none of the 14 such cases reported in the USA between 1973 and 1984 was the diagnosis of immune deficiency known prior to administration of OPV.
The risk of paralytic disease after receipt of the first dose of OPV is estimated to be one in 1.2 million doses distributed. The risk after subsequent doses is 1% of this rate. The risk of vaccine-associated paralytic disease in contacts is 1 per 1.0 million doses distributed. An alternative method of calculating risk, based on the number of children born per year, i.e. the population likely to be both susceptible and exposed to OPV, results in an estimated rate of one vaccine-associated case per 391,000 children born in the USA between 1973 through 1984.
- REPORTABLE EVENTS
Systemic allergic reactions. Paralytic disease occurring within 4 weeks of administration of OPV.