Are childhood vaccines safe, and what side effects can occur?
Approved vaccines are tested and monitored after introduction. Injection-site discomfort and mild fever are common reactions, while serious reactions are rare. Evidence does not support vaccines causing autism. Precautions depend on the vaccine and the child’s health.
Details
How safety is assessed
Health authorities weigh protection against potentially serious infection against possible adverse effects. An illness occurring after a dose does not prove the vaccine caused it; reported events are investigated. A WHO review published in 2025 reaffirmed the absence of a causal link with autism.
Before the appointment
Bring the vaccination record and mention any severe reaction after an earlier dose, known allergy or medicine that suppresses immunity. Live vaccines have different precautions from other vaccines. Do not cancel or postpone doses solely because another child had a different experience.
After vaccination
Ask which reactions to expect and when help is needed, and keep the vaccine name and date. Breathing difficulty, facial swelling or collapse requires emergency help. Routine doses and catch-up arrangements should follow the locally adopted schedule and the child’s individual history.
Related reading: When does a child’s fever need urgent assessment or emergency care?.