Live vaccines – what are the contraindications?

Summary

Health professionals are reminded that live vaccines should not be given to people who are significantly immunocompromised or pregnant. This is particularly the case for the herpes zoster vaccine – Zostavax – and the Japanese encephalitis vaccine – Imojev – as incorrect use continues to be reported. While not all reports of inadvertent use are associated with an adverse event, this safety alert provides a timely reminder to healthcare professionals considering live vaccinations for patients.

What should health professionals do

If you are uncertain about the degree of immunocompromise in a patient, do not give them a live vaccine and seek specialist advice. Detailed information to manage these patients, including tools to assess the severity of immunocompromise - external site, are available from the Australian Immunisation Handbook.^[1]

Background

There are several live vaccines available in Australia, including:

• BCG (bacille Calmette–Guérin) vaccine
• one of the Japanese encephalitis vaccines – Imojev
• MMR (measles-mumps-rubella)
• MMRV (measles-mumps-rubella-varicella)
• oral rotavirus vaccine
• oral typhoid vaccine
• smallpox vaccines against monkeypox (Jynneos, ACAM2000)
• varicella vaccine
• yellow fever vaccine
• one of the zoster vaccines – Zostavax

For most of these vaccines, the virus (or bacteria for BCG and typhoid vaccines) has been weakened (attenuated). This means when it is introduced into the body in the form of a vaccine, it induces an immune response without being able to cause the disease. However, live vaccines are contraindicated in certain patients where the risk of adverse events including vaccine-related infection is higher.

Guidance on the use of these vaccines is available in the Australian Immunisation Handbook - external site.^[1] Clinical recommendations for vaccination against monkeypox are available from the Australian Technical Advisory Group on Immunisation (ATAGI) - external site.^[2]

General contraindications for live vaccines

People who are significantly immunocompromised should not receive live vaccines due to the risk of unchecked infection. However, people with HIV who are mildly immunocompromised can receive MMR (measles-mumps-rubella), varicella and zoster vaccines with further advice from their doctor. For more information, see Vaccination for people who are immunocompromised - external site in the Australian Immunisation Handbook.

People who are immunocompromised include those who:

• are receiving high-dose immunosuppressive therapy, including biologic or targeted synthetic disease-modifying anti-rheumatic drugs (bDMARDs or tsDMARDs) or oral corticosteroids (≥20 mg per day of prednisolone equivalent dose)
• are receiving chemotherapy or radiation
• have malignancies related to the immune system such as lymphoma, leukaemia or Hodgkin disease, even if they are not receiving active treatment
• have AIDS or symptomatic HIV
• have similar immunocompromising conditions due to a disease or treatment

In general, pregnant women should not receive live vaccines and should be advised not to become pregnant within 28 days of receiving a live vaccine. See Table. Vaccines that are contraindicated in pregnancy: live attenuated vaccines - external site in Vaccination for women who are planning pregnancy, pregnant or breastfeeding - external site.

As with all vaccines, live vaccines are contraindicated in anyone who has had a severe allergic reaction to a previous dose of the same vaccine or from a different vaccine containing a component of the live vaccine, such as albumin.

Herpes zoster vaccines

There are two vaccines available to prevent herpes zoster (and its complications) in people aged 50 years and above:

• Zostavax, a live attenuated vaccine given as a single dose
• Shingrix, a subunit non-live vaccine given as two doses.

Updated guidelines from ATAGI now recommend that Shingrix is preferentially used over Zostavax in immunocompetent adults.

Zostavax is contraindicated in people with current or recent severe immunocompromising conditions from a medical condition or treatment. The Therapeutic Goods Administration (TGA) has published previous safety advisory on this issue.^[3]

The Australian Immunisation Handbook provides a screening tool – Live shingles vaccine (Zostavax) screening for contraindications - external site – to assess whether it is safe to give a patient Zostavax or delay administration. The tool lists a series of questions to guide providers and patients with these decisions.

Go to the ATAGI recommendations - external site and the Australian Immunisation Handbook - external site^[1] to find out more about herpes zoster vaccination.

Japanese encephalitis vaccines

Japanese encephalitis vaccines are routinely used for laboratory workers who may be exposed to the virus, people who live or work on the outer islands of Torres Strait, and travellers spending a month or more in endemic areas during the Japanese encephalitis transmission season.

There are two vaccines to prevent Japanese encephalitis:

• Imojev, a live attenuated vaccine given as a single dose
• JEspect (also known as Ixiaro), a non-live vaccine given as two doses

Imojev, the live vaccine, should not be given to children under 9 months of age and is contraindicated in immunocompromised individuals and women who are pregnant or breastfeeding.

Go to the Australian Immunisation Handbook - external site^[1] to find out more about Japanese encephalitis vaccination.

Disclaimer

Medicines Safety Update is aimed at health professionals. It is intended to provide practical information to health professionals on medicine safety, including emerging safety issues. The information in Medicines Safety Update is necessarily general and is not intended to be a substitute for a health professional's judgment in each case, taking into account the individual circumstances of their patients. Reasonable care has been taken to ensure that the information is accurate and complete at the time of publication. The Australian Government gives no warranty that the information in this document is accurate or complete, and shall not be liable for any loss whatsoever due to negligence or otherwise arising from the use of or reliance on this document.

© Commonwealth of Australia 2022

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Medicines Safety Update is written by staff from the Pharmacovigilance Branch.

Editor: Ms Tahli Fenner

Deputy Editor: Dr Fiona Mackinnon

Contributors: Dr Grant Pegg