What is it?

Varicella (chickenpox) is a highly contagious infection caused by the varicella-zoster virus (VZV).

What to look for

Infection usually begins with 1-2 days of fever, runny nose and lethargy.

An itchy rash follows, involving fluid filled vesicles (blisters) that can cover any part of the body including inside the mouth, eyelids and genital area. Severe complications can include pneumonia, meningitis and encephalitis.

Varicella in pregnancy can result in skin scarring, ocular anomalies, limb defects and neurological malformations for the infant.

The virus can be reactivated later in life and cause Zoster (Shingles).

How is it transmitted?

Varicella can be transmitted by coughing or sneezing, or from direct contact with the fluid inside the vesicles.

Prevention

Immunisation is the most effective form of prevention. A single dose of the live-attenuated vaccine is currently funded on the NIP for children at age 18 months of age, however giving a 2nd dose (not funded) provides greater protection. For those ≥ 14 years of age, 2 doses (administered 4 weeks apart) are required for the protection on non-immune individuals.

Post-exposure prophylaxis

If a non-immune individual is exposed to disease, immunisation is recommended within 3-5 days (provided immunisation is not contraindicated). This can reduce the likelihood of varicella infection developing. 

Neonates (whose mother develops infection up to 7 days prior to delivery or within 2 days after delivery), infants < 1-month of age (if mother is seronegative), pregnant women, premature infants (while still hospitalised, regardless of maternal serology) or immunosuppressed individuals who are exposed to varicella disease should receive Zoster Immunoglobulin (ZIG). 

Repeat doses of ZIG may be given if a person is exposed to varicella again > 3-weeks after the first dose of ZIG. 

Resources

Reviewed by: Rachael McGuire (SAEFVIC Research Nurse, Murdoch Children’s Research Institute)

Date: March 2019

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family’s personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.