Indications
Oral Poliomyelitis Vaccine (OPV) is used to protect against polio, a viral infection that can cause permanent paralysis. It is given mainly to babies and young children as part of the national immunisation programme and in polio vaccination campaigns.
How It Works
The vaccine contains live but weakened polio viruses. When swallowed, they multiply harmlessly in the gut and train the immune system to make antibodies. This protects the child from the real virus and also reduces spread of polio in the community.
Dosage and Administration
It is given by a trained health worker as drops into the mouth, following the schedule set by the national immunisation programme or the doctor. Several doses are needed in infancy, and extra doses may be given during campaigns. If the child spits out or vomits the dose within about 10 minutes, the health worker may repeat it. It is never injected.
Interactions
- Medicines that weaken the immune system (such as high-dose steroids, cancer treatment or transplant medicines) reduce the response and make a live vaccine unsafe.
- Immunoglobulin or recent blood products may lower the response; the doctor will advise on timing.
- It can be given on the same day as other childhood vaccines.
Contraindications
- Severe allergic reaction to a previous dose or to any ingredient (for example Neomycin or Streptomycin traces).
- A weakened immune system in the child, or a household contact with a weakened immune system; the injectable polio vaccine is used instead.
- The vaccine is usually postponed during a high fever or severe diarrhoea and vomiting.
Side Effects
Most children have no side effects. Mild fever, loose stools or fussiness may occur. Very rarely, the weakened virus can cause paralysis (vaccine-associated paralytic polio), estimated at about one case in several million doses, mainly after the first dose.
Get urgent medical help if the child develops sudden weakness or floppiness of an arm or leg, difficulty breathing, swelling of the face, a widespread rash, or is very drowsy or difficult to wake.
Pregnancy and Lactation
Routine use is not needed in pregnancy, but it may be given if there is a high risk of polio exposure, on medical advice. Breastfeeding does not interfere with the vaccine and can continue.
Precautions and Warnings
- Vaccinated children shed the weakened virus in their stools for some weeks: wash hands well after changing nappies.
- Tell the health worker if anyone at home has a weakened immune system.
- Keep a record of every dose on the vaccination card.
Overdose
An extra dose is not expected to cause harm. Tell the health worker if you think a dose was repeated by mistake.
Therapeutic Class
Vaccine, live attenuated viral vaccine.
Storage
Kept frozen or at 2 to 8°C by the health service according to the pack instructions, protected from light. Once thawed it is kept at 2 to 8°C and must not be refrozen. Not for home storage.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.