The Shingles vaccine was added to the National Immunisation Program in 2016. It targets all Australians on their 70th birthday. A 5 year catch up program was included for those 71 to 79 years. You become ineligible once you turned 80 years. The 5 years is up in October, 2021!
Shingles is a common disease with most older Australians easily able to recall cases amongst their friendship group. An Australian study of shingles in the period 2006-2013 estimated an overall incidence of 5.6 cases per 1000 population. However, for the age groups 60-69, 70-79 and over 80 the rates were much higher; 13.7, 15.3 and 19.9 per 1,000 population. The older cases were also more likely to experience the complications of shingles and more than 20% of patients over 50 years reported pain more than 6 months after adequate antiviral therapy!
The Chickenpox (varicella-zoster) virus can hide in the body long after a person has recovered from the initial infection. It lies "dormant" in the nerve roots of the spinal cord and can reactivate at any time; most often when the person's immune system declines due to age, stress, or illness. Herpes Simplex, the cold sore virus, behaves in a similar way, causing blistering around the mouth. The common triggers for cold sores include stress, illness, wind and sun.
The incidence of Shingles increases with age owing to a progressive decline in virus-specific immunity. When the virus reactivates, it affects the spinal nerve where it has been hiding, causing pain and a blistering rash confined to the area served by that nerve. This is called "shingles" or "zoster". Severe cases occur when the nerve involved affects the ear (Ramsay Hunt Syndrome) or eye (Herpes Zoster Ophthalmicus). Skin manifestations and pain are mostly found around the chest or lower abdomen. Severe pain may linger for months after the rash has gone. This is called "post herpetic neuralgia).
The primary illness, Chickenpox is mostly, but not always, a mild childhood illness. It can cause serious complications such as pneumonia, encephalitis, hospitalisation and occasionally death.
In November 2005, to reduce the serious complications of the disease, the Australian Technical Advisory Group on Immunisations (ATAGI) added Chickenpox immunisation to the Childhood immunisation schedule. The program targeted children at 18 months. In July 2013 it was combined with the second MMR (Measles Mumps Rubella). Vaccination was also offered to high school students in year 8 who had not experienced a bout of chickenpox. Many parents chose to vaccinate their children outside the schedule prior to year 8 using a single chickenpox vaccine (Varilrix, Varivax).
Why is the childhood chickenpox immunisation program relevant to Shingles in older Australians?
When the decision was made to vaccinate all children against chickenpox, infectious
diseases experts were worried that an unintended consequence might be an increase in shingles cases in the elderly. Chickenpox in children had long provided “natural disease boosting” to parents and grandparents. If children were protected by immunisation then this “natural” boosting wouldn’t occur and their natural level of protection would slowly decline with age. The Shingles vaccine became a substitute for the disease. It is a stronger dose (more than 14 times) the one given to children.
Studies undertaken since the launch of the 2016 Shingles program have shown a marked decrease in antiviral prescriptions specific for Herpes Zoster in the 70-79 years age group. This should reinforce the message for vaccination for those who are eligible.
Those under 70 years might seek out a “private” shingles vaccine if they travel regularly and be in situations where sourcing antiviral medication may be difficult.
Dr Bob Kass
MBBS MRCP MScMCH DCH FAFPHM