Adverse effects of the polio vaccine

The injected inactivated polio vaccine can leave temporary pain, redness, or swelling where the injection was given. Some children may be unsettled or develop a mild fever after a vaccination visit, especially when several routine vaccines are given together. These effects reflect the immune response and generally settle without specific treatment.

Oral polio vaccine contains weakened live virus and has a different safety profile. On very rare occasions, the weakened virus can change and cause paralysis in a vaccinated person or an unprotected close contact. This possibility does not apply to the injected inactivated vaccine. The vaccination record or clinic can confirm which formulation was used.

Offer fluids, allow rest, and keep the injection site clean. A cool cloth may soothe local discomfort. Do not massage the area or give aspirin to a child. If pain or fever medicine seems necessary, check the correct product and dose with a clinician or pharmacist because the choice depends on age, weight, medical history, and other medicines.

Note when symptoms began, which vaccine was given, and whether they are improving. Contact the vaccination clinic if the reaction is troublesome, lasts longer than expected, or you are unsure whether it is related. A mild illness after vaccination can also be coincidental rather than caused by the vaccine.

Call emergency services for difficulty breathing, swelling of the face or throat, widespread hives with breathing or circulation symptoms, collapse, extreme drowsiness, or a seizure. Obtain urgent medical assessment for new weakness or loss of movement, severe persistent vomiting, signs of dehydration, a fever with a very unwell appearance, or symptoms that are rapidly worsening. Stay with the person and tell responders when and where the vaccine was administered.

Tell the clinician about the previous reaction, its timing, all vaccines received that day, allergies, immune-system conditions, and medicines that suppress immunity. Ask whether the next dose should proceed as scheduled, whether a different formulation is appropriate, and what observation or follow-up is recommended.