Third primary dose of COVID-19 vaccination for individuals that are severely immunocompromised

ATAGI recommends that people with severe immunocompromise, get a 3rd dose of COVID-19 vaccine as part of their primary course. This is NOT a booster, but is intended to improve the response to the first two dose s in people who may not mount a sufficient immune response.

Individuals over 12 years of age with certain conditions or using certain therapies would be elligible.

The conditions include :

  • Certain malignancies (cancers)
  • Recipients of transplants
  • Primary immunodeficiency
  • HIV
  • Dialysis

The therapees that might suppress the immune response include:

  • Radiotherapy
  • Chemotherapy
  • High dose steroids
  • Selected conventional synthetic disease-modifying anti-rheumatic drugs (csDNARDS)
  • Biologic and targeted therapies.

Please read the complete list at


ATAGI recommends that a 3rd dose of COVID-19 vaccine be administered to eligible immunocompromised individuals 2 – 6 months after the 2nd dose (but may be sooner if circumstances require it – eg an outbreak setting)

Vaccine choice for 3rd doses

  • It is important to accept that experience in this space evolves steadily
  • Mixing vaccine brands has been shown to generate better immune responses, but it may also lead to more significant side effects. It may also be that unexpected side effects come to light with greater experience. This has to be balanced against the very real risk of harms from COVID19 infection.
  • TGA Product Information (PI) also now includes a statement that a third dose may be given to severely immunocompromised people aged 12 years and over at least 28 days after the second dose.
  • ATAGI recommends that Pfizer or Moderna be administered for the 3rd primary dose in preference to AstraZeneca..
  • Where individuals have received 1st and 2nd doses of AstraZeneca, it is acceptable for AstraZeneca to be used for the 3rd dose if there are no contraindications or precautions for receiving AstraZeneca since the last dose.
  • Where individuals have received 2nd doses of Pfizer or Moderna and further doses are contraindicated (e.g. anaphylaxis, myocarditis secondary to an mRNA vaccine), an alternative brand (e.g. AstraZeneca) should be considered.

What to do?

  1. 1. Read and conside rthe full ATAGI recommendations


  2. Talk to your usual doctor to confirm you meet the eligibility criteria and which type of vaccine your should receive. Ask your doctor to complete this form
  3. The book a “COVID19 vaccination discussion appointment” (this is a bulk billed appointment) s/general-practitioner/a/covid-19-vaccination-discussion-appt-not-for-vaccination Do not book for a vaccination appointment.
  4. Ensure you meet the criteria and have made your decision before booking a vaccination appointment.