It is recommended that injected live-attenuated vaccines such as measles-mumps-rubella (MMR), measles-mumps-rubella-varicella (MMRV) and varicella (V)/(chickenpox) be deferred for a period of time after transfusion of immunoglobulin containing blood products, including red blood cells [see MVEC: Live-attenuated vaccines and immunoglobulins or blood products]. These recommendations are based on the potential for passive transfer of immunoglobulin (IgG) in the transfused product to affect the immune response to the vaccine.

Patients requiring regular red-blood cell transfusions for a chronic haematologic condition (e.g. transfusion dependent thalassaemia, sickle cell disease, inherited chronic haemolytic anaemias, or inherited bone marrow failure syndromes), however, are unlikely to achieve a transfusion free period long enough to allow immunisation according to these recommendations.

There is limited direct data on which to base decisions in this group. The above expert recommendations are extrapolated from data on vaccine response post administration of immunoglobulin. Recommended time intervals between red blood cell transfusion and immunisation have been calculated based on the anticipated level of IgG in the red cell units, and the half-life of IgG.

This guideline is supported by the rationale that the red blood cell units transfused in Australia (red cells re-suspended in an additive solution) contain little residual plasma. The amount of immunoglobulin in transfused red cell units is therefore expected to be low. Despite this, a retrospective study of chronically transfused patients in Canada who received two doses of MMR containing vaccine before the recommended time interval, reported lower rates of immunity than expected in the general population. Seroconversion rates were however still significant, with 68% having serology consistent with immunity to measles and rubella [see resources].

Summary and recommendation

Recommendations for delay in live-attenuated vaccines post blood products are based on ensuring vaccine effectiveness. However, for patients receiving regular red cell transfusions, following these recommendations will mean indefinite deferral of live-attenuated vaccines and ongoing vulnerability to these vaccine preventable diseases.

These patients should be considered a unique group in this setting. For patients requiring chronic red cell transfusions, who will not achieve a transfusion free period of more than 3-6 months in the foreseeable future, we recommend live-attenuated vaccines be administered as per the National Immunisation Program (NIP), despite being within the usually recommended deferral period post transfusion. Please refer to your haematologist or an immunisation specialist for specific advice.

This recommendation is based on:

  • the expectation that the vaccines will still provide protection in a number of patients (albeit potentially lower than that in the general population)
  • the lack of any additional safety concerns associated with administration of the vaccine in this setting
  • the alternative being indefinite deferral of immunisation

Patients should be informed of the potential for reduced effectiveness of the vaccine.

A protocol for optimal timing of immunisation in relation to blood transfusion, serological testing post immunisation, and re-immunisation when there is no evidence of immunity, may help to improve response rates. Our local guideline can be accessed here.

Note that inactivated (non-live) vaccines can be safely administered following blood products including red blood cell transfusions.


Authors: Luisa Clucas (MVEC Immunisation Fellow), Nigel Crawford (Director SAEFVIC, Murdoch Children’s Research Institute), Margie Danchin (Paediatrician, Murdoch Children’s Research Institute and Royal Children’s Hospital) and Anthea Greenway (Paediatric Haematologist, The Royal Children’s Hospital)

Date: July 2020

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.

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