The Therapeutic Goods Administration (TGA) has required new warnings for Zostavax vaccine to address the risk of fatal disseminated vaccine strain varicella-zoster virus infection.
A new boxed warning has been added to the Product Information (PI) with information about managing this risk, including pre-screening and risk-based assessment prior to use of the vaccine, and management of suspected cases. The boxed warning is reproduced in full in the 'Information for health professionals' section below.
A corresponding warning has also been added to the Consumer Medicine Information (CMI) for Zostavax. See the 'Information for consumers' section below for more details.
The sponsor of Zostavax, Merck Sharp & Dohme, is also required to implement the following activities:
- provide a Patient Alert Card to health professionals to give to each patient receiving Zostavax (to be completed 25 June 2021)
- provide refrigerator stickers to all providers of Zostavax to place on the fridge in which the medicine is stored (to be completed 25 June 2021)
- send letters to inform health professionals of the content of the boxed warning statement (completed 28 May 2021)
- update the current Risk Management Plan and Periodic Safety Update Reports to include consideration of this risk.
Zostavax is a live, attenuated varicella-zoster virus vaccine that is used to prevent shingles in patients aged 50 years and older and prevention of nerve pain associated with the virus in patients aged 60 years and older. It is included on the National Immunisation Program (NIP) for people aged 70 to 79 years.
The TGA has been closely monitoring reports of disseminated vaccine strain varicella zoster infection and has published several safety alerts in response to three deaths related to this condition following vaccination with Zostavax.
Investigation of this safety concern has found that the benefits of Zostavax continue to outweigh the risks, but additional risk mitigation is required.
Information for consumers
The Consumer Medicine Information (CMI) for Zostavax has been updated with the following boxed warning:
WARNINGS
Zostavax is a live vaccine and should not be used in people with a weakened immune system, as it can cause serious illness and death from infection with the vaccine virus.
Tell your doctor if you are taking medicines that may weaken your immune system including high-dose corticosteroids or cancer medicines, or other treatment.
If you become unwell after vaccination, you should seek medical attention and tell your doctor that you have recently received Zostavax.
Seek immediate medical attention if you:
- develop a chickenpox-like rash within 2 to 4 weeks of vaccine administration
- feel unwell
- develop a fever.
Varicella-zoster virus is the virus that causes chickenpox and shingles. Infection with varicella-zoster virus can be localised to an area of skin, but can also take a more serious, generalised form that affects a wider area of the body. Widespread infection is called disseminated varicella zoster virus infection.
The most common adverse events following Zostavax are reactions at the site of injection, such as redness, pain and swelling. Serious reactions, such as the disseminated varicella-zoster virus infection reported in this advisory and updated within the Consumer Medicine Information (CMI), are very rare.
If you are concerned about whether you or someone you provide care for can receive Zostavax, please speak to your health professional.
For further information about adverse events following Zostavax, please refer to the CMI. The CMI can be accessed on the TGA website or requested from your doctor or pharmacist.
Your doctor may also provide a patient safety alert card which details important safety information that you need to be aware of before and after treatment with Zostavax.
Information for health professionals
The Product Information (PI) for Zostavax has been updated with the following boxed warning:
WARNINGS
Rarely, disseminated varicella zoster virus (VZV) infection with vaccine (Oka) strain can occur in patients following administration of the live-attenuated Zostavax vaccine. There have been fatal reports of disseminated vaccine-related VZV infection in Australia, including in patients on low dose immunosuppressive medication. The risk increases with the degree of immunosuppression.
Zostavax is contraindicated in patients with current or recent severe immunocompromising conditions from either a primary or acquired medical condition or medical treatment (See 4.3 Contraindications).
Careful pre-screening and a risk-based assessment is required prior to administration of any dose of Zostavax. If appropriate, this assessment should include medical specialist consultation and potentially screening for pre-existing antibody to VZV. In such cases, vaccination should be deferred until such advice and/or results have been obtained.
The Australian Immunisation Handbook contains specific guidance about Zostavax administration in patients who are immunocompromised or have medical conditions that place them at risk of immunocompromise. If uncertain about a person’s level of immunocompromise and whether vaccination is safe, do not vaccinate and seek further specialist advice.
Any patient who experiences a disseminated vesicular (chickenpox-like) rash 2 to 4 weeks after vaccine administration, or who feels unwell or has a fever, should seek medical attention immediately and ensure that their treating health professional is aware of their recent vaccination history.
If inadvertent vaccination in an immunosuppressed patient has occurred, the patient should be advised regarding the potential for disseminated VZV infection and the need to seek medical advice should symptoms suggestive of this occur, so that they can be considered for pre-emptive antiviral therapy.
If a recent Zostavax recipient is suspected of having disseminated VZV infection, the healthcare professional should:
- conduct appropriate diagnostic testing early in consultation with a clinical microbiologist or infectious diseases physician
- where appropriate, initiate appropriate empiric antiviral therapy whilst awaiting test results
- where feasible, cease immunosuppression in consultation with their treating specialist.
The sponsor, Merck Sharp & Dohme, has distributed a Dear Health Care Professional Letter providing further information on this product. Additionally, fridge stickers and patient alert cards are expected to distributed to doctors by 25 June 2021.
If you have further questions, please contact the distributor, Seqirus, on 1800 642 865.
Reporting problems
Consumers and health professionals are encouraged to report problems with medicines or vaccines. Your report will contribute to the TGA's monitoring of these products.
The TGA cannot give advice about an individual's medical condition. You are strongly encouraged to talk with a health professional if you are concerned about a possible adverse event associated with a medicine or vaccine.