Chicken Pox - Varicella

What is chickenpox and how do you get it?

Every year in New Zealand there are many of cases of chickenpox - around 50,000.1 Although the disease is mild for most children, about 150–200 cases end up in hospital with severe complications such as bacterial skin infections, brain inflammation (meningitis and encephalitis) and nerve damage.  (1,2)   Most severe cases occur in children who were otherwise healthy.(1)


The chickenpox (varicella) virus is very easy to catch and is usually spread by droplets in the air when an infected person coughs or sneezes.(1,3) This means that anyone in your family who is exposed to chickenpox and hasn't had it before is likely to get sick.(4)   It takes between 10-21 days before symptoms show, so often brothers and sisters will get sick one after the other. (1)  The infection usually starts with a fever, then a rash appears that turns to blisters and spreads to different parts of the body in waves. (2,3)   On average children have about 200-400 blisters, which sometimes leave scars. (2)   The virus can be spread from 1 or 2 days before the rash emerges until the last rash dries up, about 1-2 weeks later. (1,2)


How do you treat chickenpox?

Infected children are advised to be kept at home and out of daycare or school until all rash lesions have crusted. (1)   Sometimes a soothing lotion such as calamine lotion can help with the itching of the blisters. (4)   Give paracetamol for fever or pain.1,4 Do not give aspirin to children with chickenpox as this might increase the risk of a rare severe condition called Reye's Syndrome. (1,4)


How do you prevent chickenpox?

Prevention of infection by vaccination is the most effective way to prevent the serious effects of chickenpox . (3-6)   One dose of the vaccine is about 80-85% effective at preventing all chickenpox and two doses are about 92-97% effective. (2,5)

The benefits of choosing to vaccinate means your child will:
• avoid hospitalisation and severe disease (1,5)
• avoid long term scarring of the body from chickenpox blisters (2)
• avoid suffering itching, blisters and discomfort (2,4)


Immunity lasts for at least 20 years, which is as long as vaccinated people have been followed. (6)   If a vaccinated child does get chickenpox, the illness is much milder. (2)   The chickenpox vaccine is generally well tolerated, with most side effects occurring around the injection site; for example, soreness and redness. (5)


In New Zealand, the chickenpox vaccine is recommended for children, but is not funded. (1)   The vaccine is available for purchase through your family doctors. Talk to your doctor or nurse to see if the vaccine is right for your child.


For more information contact the Immunisation Advisory Centre on 0800 IMMUNE or visit


1. Ministry of Health; Immunisation Handbook 2011, Wellington: Ministry of Health; 2011.
2. Heininger U, Seward JF. Lancet 2006 14;368:1365–76.
3. Walls T, Wilson E. NZMJ 2010;123:22-5.
4. Kidshealth Chickenpox. Available at: Accessed 6th June 2012.
5. Varilrix® Data Sheet, GSK New Zealand. July 2011.
6. Takahashi M. Paediatr Drugs. 2001;3:285–92


Varilrix® (live attenuated varicella vaccine) is available as an injection. Varilrix is a private-purchase prescription medicine for immunisation and prophylaxis against varicella (chickenpox) in adults and children older than 9 months. You will need to pay for this medicine. Children aged 13 years and older need two doses with an interval between doses of at least 6 weeks. Two doses at least 6 weeks apart are also recommended for children aged between 9 months and 12 years, to provide optimal protection. Use strictly as directed. Do not have a Varilrix injection if you are allergic to Varilrix or to the antibiotic neomycin, if you have a high fever, if you have a condition that causes lack of immunocompetence, or if you are pregnant. Pregnancy should be avoided for 3 months after vaccination. Tell your doctor before you have the vaccine if you have a lowered resistance to disease or have a severe chronic disease. Common side effects: mild rash, a small number of chicken-pox-like blisters, or pain, redness and swelling at the injection site. Uncommon side effects include fever, headache, cough, vomiting, swollen lymph nodes, and joint pain. If you have any side effects, see your doctor, pharmacist, or health professional. Additional Consumer Medicine Information for Varilrix is available at Prices for Varilrix may vary across doctor's clinics. Normal doctor's office visit fees apply. Ask your doctor if Varilrix is right for you. Varilrix is a registered trade mark of the GlaxoSmithKline group of companies. Marketed by GlaxoSmithKline NZ Limited, Auckland. TAPS NA5862JU/0005/12