Document showing the absolute risk reduction of each covid vaccine

Jaay-H made this Freedom of Information request to Therapeutic Goods Administration

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Dear Therapeutic Goods Administration,

The TGA provisionally approved covid vaccines earlier this year. Please provide a document showing the absolute risk reduction of each of those vaccines. This is an FOI request.

Yours faithfully,


TGA FOI, Therapeutic Goods Administration

Dear Jaay-H,

Thank you for your email below dated 27 July 2021 in which you sought access to the following documents under the Freedom of Information Act 1982 (the FOI Act):

“The TGA provisionally approved covid vaccines earlier this year. Please provide a document showing the absolute risk reduction of each of those vaccines.”

We note that 'Absolute Risk Reduction (ARR)' is taken to mean the evidence based medicine term which is calculated as the simple mathematical difference between event rates in two groups of a clinical trial, in this case the difference in rates of COVID-19 cases between those who received the vaccine and those who did not.

The ARR can be calculated from publicly available information given the number of COVID-19 cases seen in the clinical trials are available, amongst other information, in the Product Information (PI) for the COVID-19 vaccines published on the TGA website.

The PI for each COVID-19 vaccine is available at: by clicking on 'Provisional Registrations' and then selecting each vaccine. Information on the number of COVID-19 cases observed in each clinical trial, in order to calculate the ARR, is typically found under the 'Clinical Trials' subheading in the PI.

Further information on the clinical data considered and TGA's evaluation process is available in the Australian Public Assessment Reports, available here:

Vaccine efficacy is typically quoted as Relative Risk Reduction (RRR), which is the ARR expressed as a proportion of the event rate in the untreated group. ARR and RRR are not contradictory, but rather complementary ways of expressing risk from the same data set. Real-world use of COVID-19 vaccines to date internationally has shown good generalisability of results seen in clinical trials, noting that the pandemic is dynamic and the risk of COVID-19 at any given time in any particular location is subject to change.

To assist, information on how to calculate ARR and RRR is available at the following link:

We trust that this information assists. As the information you have requested is publicly available, the TGA is not required to process this request under the FOI Act and your request is considered withdrawn.

Freedom of Information

Therapeutic Goods Administration
Australian Government Department of Health
T: 02 6289 4630 | E: [email address]
PO Box 100, Woden ACT 2606, Australia

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