7 July 2020

Zostavax kills eligible patient, vax alternative still unavailable

Clinical

A patient with arthritis has died after being vaccinated with Zostavax, leading the TGA to issue a safety message reminding doctors about the risks of using this vaccine in immunocompromised patients.

The patient, who died three weeks after receiving Zostavax, was taking hydroxychloroquine and a low dose of prednisolone to treat arthritis.

While Zostavax is contraindicated in patients who have compromised immune function, this low dose of prednisolone was not enough to make this particular patient ineligible for the vaccine.

A TGA investigation found that Zostavax was used in line with existing recommendations.

The vaccine does carry a risk of varicella-zoster infection even in patients who are only on low-dose immunosuppressants, which can cause mild to serious complications, including death, the TGA said.

“It is important for health professionals to be mindful of the potential for this very rare adverse event,” the TGA said.

Careful pre-screening of patients who are on low-dose immunomodulation, as outlined in the Australian Immunisation Handbook, can help doctors assess the risks of Zostavax.

“If necessary, this could include medical specialist consultation and potentially screening for pre-existing antibody to varicella-zoster virus,” the TGA said.

If a Zostavax recipient was suspected of having developed an infection, the doctor should conduct appropriate diagnostic testing early, initiate acyclovir while awaiting test results and cease immunosuppression where feasible.

Zostavax is a live, attenuated vaccine that is included on the NIP for the prevention of shingles in people aged 70 to 79 years.

It provides 51% protection against shingles and 67% against postherpetic neuralgia over three years.

The non-live shingles vaccine, Shingrix, was approved by the TGA in July 2018 for people aged 50 years and above but has global supply issues and will not be available in Australia any time soon.

This recombinant vaccine is more effective than Zostavax, providing 97% protection against herpes zoster for 50–59 year olds and 91% for those aged over 70 years, within similar levels of protection against postherpetic neuralgia over more than three years.

Shingrix may be safer in patients who are immunocompromised, although it can’t be recommended for this patient group yet because there is not enough evidence, according to the CDC.

“You can still give Shingrix to someone who is taking low-dose immunosuppressive medication, anticipating immunosuppression, or has recovered from an immunocompromising illness,” the CDC said.

The latest safety notice from the TGA shows that there’s a need for more vaccine alternatives, said Dr David Liew, a rheumatologist at Austin Hospital in Victoria.

“I think it does clearly emphasise the imperative for a non-live zoster vaccination option, such as Shingrix – even if access is limited to a rheumatic disease population,” he said.

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