Varicella shot: what to know before vaccination

The vaccine exposes the immune system to a weakened form of varicella so it can recognise the virus later. It is intended to prevent or reduce the severity of chickenpox, not to treat active infection. Protection planning depends on age, previous doses or illness, immune status, pregnancy, and medicines that affect immunity. A history of chickenpox may be relevant, but memories and records are not always complete.

Tell the vaccinator about allergies, pregnancy or plans for pregnancy, recent illness, previous vaccine reactions, and immune-suppressing treatment. Bring written records when available. After the shot, keep the injection area clean and follow the clinic's advice about ordinary activities. Mild soreness or a short-lived fever can occur; ask before taking medicine, especially for a child. More guidance is available through [Chickenpox Vaccination](/treatments/preventive-care-and-vaccination/chickenpox-vaccination/).

Get urgent help for breathing difficulty, swelling of the lips or face, collapse, or rapidly spreading hives after vaccination. Contact a clinician if fever is persistent, the person seems unusually unwell, or a blistering rash develops. A fever or rash can also reflect an infection unrelated to vaccination, so assessment should be based on the whole picture. See [Fever](/symptoms/fever/) and [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/).

Ask whether this vaccine is suitable with your medical history, whether a further dose is needed, and what interval applies. Ask how to distinguish an expected reaction from a problem and whom to contact outside clinic hours.