A fatal case of varicella-zoster virus infection after shingles vaccination is being highlighted by the TGA as a reminder to clinicians that the live zoster vaccine may pose a rare but serious risk of infection even in patients on low doses of immunosuppressive therapy.
The TGA has released details of a case of a patient with arthritis who was taking hydroxychloroquine and a low dose of prednisolone, and who died of disseminated varicella-zoster virus infection three weeks after receiving Zostavax.
An investigation of the case found that Zostavax had been used in line with existing recommendations, which allow the vaccine to be given to people on long term stable low dose corticosteroid therapy (defined as ≤20mg prednisone per day for ≥ 14 days).
The TGA safety advisory said that while such infections are rare, clinicians should be aware of the risks prior to vaccination and be vigilant and ready to act on any signs of zoster infection after vaccination.
“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,” it said.
If a patient is suspected of having varicella-zoster infection after shingles vaccine, the clinician should be prepared to do early diagnostic testing, start acyclovir empirically while awaiting test results and stop immunosuppression where feasible.
“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,” it said.
“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.”
A new non-live shingles vaccine Shingrix has been licensed by the TGA since 2017 but a global shortage means that it is not yet available in Australia. Manufacturer GSK says there is currently no confirmed timing for the supply of Shingrix to Australia.