AstraZeneca Vaccines

Why is a third dose of the COVID-19 vaccine recommended for some individuals? 

ATAGI recommends a 3rd dose of the COVID-19 vaccine as part of the primary course in individuals who are severely immunocompromised. This is to address the risk of suboptimal or non-response to the standard 2 dose schedule.  The 3rd dose is intended to maximise the level of immune response to as close as possible to the general population. The recommendation applies to all individuals aged ≥12 years with certain conditions, or on therapies, leading to severe immunocompromise.

An mRNA vaccine (Pfizer or Moderna) is preferred to Vaxzevria (AstraZeneca) for this 3rd dose. AstraZeneca can be used for the 3rd dose for individuals who have received AstraZeneca for their first 2 doses if there are no contraindications or precautions for use, or if a significant adverse reaction has occurred after a previous mRNA vaccine dose which contraindicates further doses of mRNA vaccine (e.g., anaphylaxis, myocarditis).

The recommended interval for the 3rd dose is 2 to 6 months after the 2nd dose of vaccine. A minimum interval of 4 weeks may be considered in exceptional circumstances (e.g., anticipated intensification of immunosuppression, outbreaks). People who have had a second dose more than 6 months ago should receive a 3rd dose whenever feasible.

Who should consider a third dose of the COVID-19 vaccine? 

For comprehensive information on people with immunocompromising conditions and therapies for which a 3rd primary dose is recommended, please click here.


How to book a COVID-19 vaccine appointment

The video below takes you through the step-by-step process of joining the reservation list for your COVID-19 vaccine. 

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ATAGI statement on use of COVID-19 vaccines in an outbreak setting

On the 13 July 2021, the Australian Therapeutic Advisory Group on Immunisation (ATAGI) addressed the use of COVID-19 vaccines amongst Sydney's outbreak. They made the following recommendations:

  1. ATAGI's advice remains unchanged in age groups over 60. They have reinforced that the benefits of being vaccinated with the AstraZeneca vaccine strongly outweigh the risks of adverse side effects in the age group. Vaccination is essential for this group in the context of an outbreak. 

  2. Where access to the Pfizer (Comirnaty) vaccine is restricted, adults younger than 60 years old should re-assess the benefits to them and their contacts from being vaccinated with AstraZeneca versus the risk of a serious side effect. 

  3. The preferred interval between AstraZeneca doses has been shorted to 4 to 8 weeks in the context of an outbreak. Therefore, if you had your first dose of AstraZeneca more than 4 weeks ago, you should book in to arrange your second dose as soon as possible. In a non-outbreak setting, the interval will remain at 12 weeks.

When the virus is spreading in the community, it is critical that as many people as possible are vaccinated as quickly as possible. As such, the benefits of the AstraZeneca vaccine during an outbreak are increased compared with non-outbreak settings.

How can I book my second dose of the AstraZeneca COVID-19 vaccine at Double Bay Doctors?

If you received Dose 1 of the AstraZeneca vaccine at Double Bay Doctors, you will receive a secure SMS with a link to book your Dose 2 vaccine.


You may book your Dose 2 vaccine anytime after 4 weeks after receiving Dose 1.


You will have 48 hours to book your vaccine appointment after receiving your SMS invitation, before the reserved vaccine is offered to another patient. 


Please see below for the latest information on the interval between dose 1 and dose 2 of the AstraZeneca vaccine. 


Flu vaccines - please note you cannot receive the AstraZeneca vaccine within 7 days of receiving the flu vaccine. 


When should I receive Dose 2 of the AstraZeneca vaccine?

On Tuesday 13 July 2021, ATAGI released updated recommendations on the interval between AstraZeneca doses in an outbreak setting. You can now receive your second dose anywhere between 4 to 8 weeks after your first.




Before you proceed with booking your second dose of the AstraZeneca vaccine, it is important that you are aware of the following important information:


+ If you have received the first dose of the AstraZeneca vaccine, you cannot elect to receive the Pfizer vaccine for your second dose, except in very limited circumstances which include: incidence of anaphylaxis to your first dose of AstraZeneca, or history of one of the contraindications to AstraZeneca.​

+  If you are deciding whether to have your second dose of AstraZeneca earlier than the  recommended 12-week interval, you should be aware of the following:


+ Research has shown that two doses of the AstraZeneca vaccine affords greatest protection from COVID-19 generally and in particular for the Delta strain currently circulating in Greater Sydney;


+ The current guidance from Australian Technical Advisory Group on Immunisation (ATAGI) states that ‘the recommended interval between two doses of COVID-19 Vaccine AstraZeneca is 12 weeks’ and ‘vaccine efficacy following the second dose of COVID-19 Vaccine AstraZeneca progressively increased with a longer interval between doses’.  ‘Shortening the interval from 12 weeks to no less than 4 weeks between doses is acceptable and may be appropriate in certain circumstances’.


+ Shortening the gap between first and second doses will bring forward short term protection, which is expected to be beneficial in outbreak situations. On this basis, an interval of between 4 and 8 weeks between the first and second doses of COVID-19 Vaccine AstraZeneca is preferred in an outbreak situation.  In non-outbreak settings, the preferred interval between doses of COVID-19 Vaccine AstraZeneca remains at 12 weeks.  


Interval between first and second dose of Covid-19 Vaccine AstraZeneca Vaccine Efficiency for prevention of symptomatic confirmed COVID-19 and Vaccine Efficiency for prevention of symptomatic confirmed COVID-19*











*Data taken from ATAGI Clinical Guidance on COVID-19 Vaccine in Australia _ v5.0

What to do next


If you decide you would like to book, change or cancel your second dose appointment you can do this through the AMS Connect app or through our online booking system at You can access easy to follow instructions on our website.


If you are unsure of how to proceed, you should discuss this with your doctor before attending your vaccine appointment.


<6 weeks - 55.1%
6-8 weeks - 59.9%
9-11 weeks - 63.7%
>12 weeks - 81.3%


What to bring
Please remember to bring photo ID to your vaccination appointments.

Non Medicare card holders

If you don't have Medicare you can still access the COVID-19 vaccine free of charge. Non Medicare card holders are required to access the vaccine at a public vaccination site. The closest alternative is the Bondi Junction Respiratory clinic.

Looking for more information?

Please visit our comprehensive list of FAQs for more information. 

Contact us

Please email us at with your COVID-19 vaccine related enquiries.