Could a new immunisation programme eliminate chickenpox in New Zealand?
About 60,000 Kiwis are infected with chickenpox (varicella) every year. Of those, several hundred are hospitalised with some cases resulting in serious medical complications and occasionally death, says Dr Helen Petousis-Harris, Director of Research at the Immunisation Advisory Centre and The University of Auckland.
Dr Petousis-Harris believes a new immunisation programme will virtually eliminate serious forms of this disease which disproportionately results in higher numbers of hospitalisations for Māori and Pasifika children.
A study into the impact of the disease found that Māori and Pasifika children are over-represented with an almost three- and four-fold increase risk of hospitalisation.
Dr Petousis-Harris says the inclusion of a chickenpox vaccine in the National Immunisation Schedule means for the first time there is an opportunity to reduce the impact of the disease on New Zealand children and their whānau.
Dr Petousis-Harris says according to a Starship study, Māori and Pacific Island children are much more likely to be admitted to ICU from chickenpox complications (secondary bacterial infection) compared with other ethnicities. Reasons for this disparity include household crowding, economic deprivation and other environmental causes.
She says, "From overseas experience we can see that once the varicella vaccine is introduced into a population, the incidence of severe disease can be reduced by over 70% in vaccinated populations."
Dr Petousis-Harris also says a critical factor in controlling severe disease is high coverage which will help the development of herd immunity, which means it’s crucial that parents vaccinate their children on time.
Last week, Health Minister Dr Jonathan Coleman welcomed the introduction of free chickenpox vaccination for 15-month-olds from July 1, saying it will have a significant impact on reducing the harm caused by the disease.
"Chickenpox is a common childhood disease that is usually mild, but can lead to complications including scarring, skin infections, pneumonia, eye damage, swelling of the brain and kidney problems.
“One dose of chickenpox (or varicella) vaccine is funded for children turning 15 months of age on or after 1 July 2017. This will protect most immunised children from chickenpox. The few who do still catch the disease despite being immunised will be protected from its most severe effects,” says Dr Coleman.
Chickenpox vaccines are well-established, being available in over 95 countries and in use for over 30 years. It has been available for purchase in New Zealand since the 1990s.
For more information, contact your GP or visit the Ministry of Health website.