A brief history
Chickenpox was once commonly confused with smallpox before the two illnesses were reliably distinguished. A live attenuated chickenpox vaccine was developed in the 1970s. The infection is caused by varicella-zoster virus, which can remain dormant after recovery and later reactivate as shingles.
How does it spread?
The virus spreads readily through the air and contact with fluid from chickenpox blisters. People can be infectious before the rash appears and remain infectious until the lesions have crusted. A susceptible person exposed to shingles can also develop chickenpox.
Symptoms and possible complications
An itchy rash develops into fluid-filled blisters, often with fever and tiredness. Most children recover without serious problems, but bacterial skin infection, pneumonia and brain inflammation can occur. Adults, pregnant people, newborns and those with weakened immunity are more vulnerable to complications. Exposure in these groups warrants prompt medical advice.
Where it may be relevant
- Non-immune adults and children for whom private vaccination is appropriate
- People with close contacts at higher risk of severe chickenpox after clinical review
- Travellers or workers needing evidence-based protection
Dose schedules
The clinician will select the appropriate licensed schedule after reviewing age, health, previous doses and departure date.
Two-dose course
Eligible adults and children
The minimum interval depends on age and product.
Who may be eligible
- People from the selected product's licensed age without reliable evidence of immunity
- Those able to avoid pregnancy for the period specified after this live vaccine
Who may not be eligible
- Anyone with a confirmed severe allergic reaction to a previous dose or a vaccine ingredient
- People who are acutely unwell with a significant fever may need vaccination deferred
- Pregnancy, breastfeeding, immune suppression and current medicines must be reviewed individually
- Pregnancy and significant immune suppression are contraindications to this live vaccine
- Recent blood products and some antiviral medicines may affect timing
Potential side effects
- Pain, redness or swelling where the injection is given
- Headache, tiredness, muscle aches or a mild fever
- Feeling faint around the time of vaccination
Important risks and precautions
- A severe allergic reaction is very rare and requires urgent treatment
- Protection is not absolute, so relevant food, water, bite or exposure precautions remain important
- The exact product and schedule must be confirmed during a clinical assessment
- A mild vaccine-related rash can occur; contact with highly vulnerable people may need to be avoided if this develops
Clinical references