Government health authorities have recently gone in to overdrive warning GPs of the contraindications for giving the new shingles vaccine, Zostavax.
The flurry of alerts follow the death of a patient here in Australia who was given the vaccine despite being immunocompromised.
This contraindication is not new however the authorities are obviously concerned it could be overlooked, especially in light of the fact that immunosuppression is a risk factor for developing shingles. In addition, the age group now eligible for the free vaccine is likely to suffer significant morbidity should they experience a Herpes Zoster outbreak including the development of post-herpetic neuralgia.
“Zostavax is a game-changer in terms of vaccination”, says Associate Professor Kristine Macartney, staff specialist in infectious diseases and Microbiology at the Children’s Hospital at Westmead, Sydney.
You can give flu or pneumococcal to practically anyone without the risk of causing much harm, she said at the recent Women’s and Children’s Health Update conference in Melbourne. However, give the new zoster vaccine to the wrong patient and the result can be disastrous.
Zostavax is a live vaccine containing 14 times more virus than childhood varicella vaccine. Consequently, giving the vaccine to a patient whose immune system is suppressed can result in disseminated disease.
So who is regarded as being immunosuppressed?
Obviously people with haematological or generalised malignancies such as lymphoma or leukaemia would not be eligible. Either would solid organ or bone marrow transplant recipients.
But perhaps less well recognised are people on the newer disease modifying anti-rheumatic drugs (DMARDs) such as etanercept and infliximab. Or people on higher doses of the immunomodulators azathioprine, 6-mercaptopurine or methotrexate.
In addition, immunosuppressive therapy should not be started for at least one month after Zostavax is given. And the contraindication for giving this live zoster vaccine extends for up to 12 months after the patient has stopped taking these immunosuppressive medications.
The list of immunosuppressive medications that mean Zostavax should be withheld is quite extensive and can sometimes be complex as in the case of corticosteroids.
Dr Macartney recommends checking the online version of the Australian Immunisation Handbook. The online version is preferable to the hard copy which is now out of date as there have been at least six updates of the information since the print copy was last published in 2013.
Early problems with the supply of Zostavax appear to be resolved and the vaccine is again appearing in practices’ fridges, health authorities are all saying if there is any doubt as to whether Zostavax is safe for your particular patients it is best to defer vaccination and seek specialist advice.
And should an immunosuppressed patient be given the vaccine inadvertently it is advised that the treating specialist or an infectious disease specialist be contacted urgently with a view to the possible early use of antivirals.