其 他 安 全 警 示
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| Australia: Zostavax vaccine: Safety advisory: not to be used in people with compromised immune function (English only) |
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The Therapeutic Goods Administration (TGA) has previously advised that Zostavax should not be used in people with compromised immune function, as it is associated with a risk of mild to serious complications (including death) from infection with the vaccine virus.
Consumers and health professionals are advised that the TGA has received a report of a new case involving this adverse event in a patient on low doses of immunosuppressive medicine. The patient, who at the time of vaccination was taking hydroxychloroquine and a low dose of prednisolone to treat arthritis, died 3 weeks after receiving Zostavax. The TGA investigation found that Zostavax was used in line with existing recommendations. However, it is important for health professionals to be mindful of the potential for this very rare adverse event.
In Australia, Zostavax is a live, attenuated varicella-zoster virus vaccine that is used to prevent shingles in patients aged 50 years and older and prevention/treatment of nerve pain associated with the virus in patients aged 60 years and older. Zostavax is included on the National Immunisation Program for people aged 70 to 79 years.
Consumers are advised that, if they are concerned about whether they or someone they provide care for can receive Zostavax, please speak to their health professional. The most common adverse event following Zostavax are injection site reactions. Serious reactions, such as the disseminated varicella-zoster virus infection reported in this advisory, are very rare. If they become unwell after vaccination, they should seek medical attention and tell their doctor that they have recently received Zostavax. Seek immediate medical attention if they develop a chickenpox-like rash within 2 to 4 weeks of vaccine administration, feel unwell or develop a fever.
Health professionals are reminded that, on rare occasions, disseminated varicella-zoster virus (Oka vaccine strain) infection can occur in patients following administration of Zostavax vaccine. This case has demonstrated that this can occur in patients who are on low dose immunomodulation and demonstrates the importance of careful prescreening and a risk-based assessment prior to Zostavax administration. If necessary, this could include medical specialist consultation and potentially screening for pre-existing antibody to varicella-zoster virus. If a recent Zostavax recipient is suspected of having disseminated varicella-zoster virus infection the health professional should conduct appropriate diagnostic testing early; where appropriate, initiate acyclovir empirically while awaiting test results; where feasible, cease immunosuppression.
The TGA convened an expert panel consisting of infectious disease physicians (with expertise in vaccines and vaccine safety), a rheumatologist and a respiratory physician to review the role of Zostavax vaccine in the death of the patient. The Panel reviewed the case details and the available published literature using a World Health Organization causality assessment framework. The Panel noted that the vaccine was administered consistent with existing recommendations, with the dose of hydroxychloroquine and prednisolone below the level expected to cause significant immunosuppression. The Panel concluded that the clinical findings were consistent with a causal association between Zostavax and fatal (vaccine-related) varicella-zoster virus infection. The panel also noted that a high index of suspicion, early diagnostic testing, prompt empirical antiviral therapy, and where feasible, cessation of immunomodulatory therapy, are all important in such cases.
This case draws attention to the potential for the rare event of disseminated vaccine-related varicella-zoster virus infection in patients on low doses of immunosuppressive medication, occurring typically 2 to 4 weeks after Zostavax vaccination. Disseminated varicella-zoster virus infection is potentially life-threatening and suspicion should prompt appropriate diagnostic testing, initiation of empirical acyclovir treatment while awaiting test results and, where possible, cessation of immunosuppression. Patients should be advised to seek medical attention if they become unwell after receiving Zostavax, and to ensure that they mention their vaccination history to their treating health professional.
Please refer to the following website in TGA for details:
http://www.tga.gov.au/alert/zostavax-vaccine-0
In Hong Kong, Zostavax For Vaccine (HK-55419) is a pharmaceutical product registered by Merck Sharp & Dohme (Asia) Ltd, and is a prescription-only medicine. So far, the Department of Health (DH) has received 6 cases of adverse events following immunisation with Zostavax, but none of them involved death. Related news was previously issued by TGA, and was posted on the Drug Office website on 8 Mar 2017. The current local product insert includes immunosuppressed and immunodeficient individuals as contraindications. The DH will remain vigilant on safety update of the product issued by other overseas drug regulatory authorities.
Ends/Tuesday, Jul 7, 2020
Issued at HKT 16:00
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