Poliomyelitis is a serious condition which causes paralysis and death. The best way to prevent it is by vaccination. There are two types of polio vaccines, which are the live poliovirus vaccine given orally (OPV) and an inactivated poliovirus vaccine given by injection (IPV).
IPV is routinely used in Hong Kong. IPV is given at 2 months, 4 months and 6 months of age, with reinforcing doses (boosters) at 18 months, 6 years and again at 12 years old. Boosters thereafter are not normally necessary, unless travelling to an area where polio is common. The vaccine is injected with a fine needle under the skin on the thighs of infants or on the arms of older children.
In immunization using the OPV, a single drop of vaccine is delivered in milk, syrup, food or the popular cube of sugar.
For infants travelling to areas of high risk, the primary doses of vaccines are recommended to be completed prior to departure. Travellers to polio-infected countries and areas who have previously received three or more doses of OPV or IPV should be offered another dose of polio vaccine before departure. For frequent travellers to polio-infected areas for brief periods of time, a one-time only additional dose of polio vaccine after the primary series should be sufficient to prevent disease.
Side effects to polio immunisations are infrequent, and the risk of paralysis from the vaccination is extremely rare (estimated at one case per 3.4 million doses).
There are reasons for not giving polio vaccine:
- Acute illness with a raised temperature;
- Diarrhoea and/or vomiting;
- Treatment with high doses of steroids or drugs that suppress the immune system and also some forms of radiation therapy;
- Conditions which suppress the immune system such as leukemia and lymphomas;
- First four months of pregnancy, although no evidence exists of harm done to a baby born after such administration of vaccine;
- If you are allergic to certain antibiotics (penicillin, neomycin, polymyxin or streptomycin).