The most common side effect from the chickenpox vaccine is swelling, soreness, or redness at the site of the injection. A small number of people may also develop a mild rash or a low-grade fever after vaccination. Serious reactions to the chickenpox vaccine are extremely rare, but they may include:
- Seizures
- Brain infection
- Pneumonia
- Loss of balance
- Severe allergic reaction (anaphylaxis)