A New Zealand scientist believes that chickenpox, a disease that can lead to serious complications and even death and that causes hundreds of hospitalisations annually, is closer to being eradicated in New Zealand.
Dr Helen Petousis-Harris, director of research at the Immunisation Advisory Centre and the University of Auckland says each year 60,000 Kiwis are infected with chickenpox (varicella) and of those several hundred are hospitalised, with some resulting in serious medical complications and occasionally death. Parents may think chickenpox is a childhood rite of passage and that it’s nothing to be concerned about, when in fact it can have disastrous, potentially fatal consequences.
The inclusion of a chickenpox vaccine in the National Immunisation Programme means for the first time we have the opportunity to reduce the impact of severe disease on New Zealand children and their families, says Dr Petousis-Harris.
From July 2017, one dose of Varilrix will be included in the National Immunisation Programme at the 15 month immunisation visit as the chickenpox vaccine. For 11-year-olds who haven’t been vaccinated or had chickenpox in the past, one dose is also available from their GP.
Children born before April 2016 (i.e. they are older than 15 months on 1 July 2017), won’t qualify for funded vaccination until they are 11 years old by which time they will have probably already had chickenpox. For children that don’t qualify, Varilrix can be purchased from the doctor.
“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” she says.
Dr Petousis-Harris says a critical factor in controlling severe disease is high coverage which will help the development of herd immunity — this means it’s really important that parents ensure that their children are vaccinated on time.
Herd immunity is a form of indirect protection from infectious disease that occurs when a large percentage of a population has become immune to a disease, thus reducing its circulation in the community and providing a degree of protection for those who are not immune.
“Herd immunity helps protect the most vulnerable; those who cannot be vaccinated such as people with cancer and serious conditions that affect the immune system and those who have a limited response to the vaccine. At the same time, it helps stop transmission of the virus and protects those groups who have not been vaccinated”.
An Auckland GP, Dr John Cameron who is a great supporter of the introduction of the chickenpox vaccine onto the National Immunisation Schedule, is also stressing the importance of on-time immunisation “With high coverage the new programme will get rid of most of the disease, which is why it is so important that children are immunised on time,” he says.
Chickenpox vaccines are well established being available in over 95 countries and in use for over 30 years.