Question Number: 137
PDR Number: SQ22-000150
Date Submitted: 24/02/2022
Department or Body: Department of Health
105. The Therapeutic Goods Administration (TGA) uses the Relative Risk Reduction (RRR) to report vaccine efficacy.
RRR and Absolute Risk Reduction (ARR) are two ways of looking at the same data. Vaccine efficacy, expressed as RRR, means the vaccine will reduce the risk of infection by the reported percentage irrespective of the transmission setting. It is therefore more meaningful to make vaccine-related regulatory decisions using RRR.
RRR is the endpoint of choice for all vaccines, including COVID-19 vaccines, as recommended by the European Medicines Agency’s Guideline on clinical evaluation of new vaccines (see: www.ema.europa.eu/en/documents/scientific-guideline/guideline-clinical-evaluation-new-vaccines_en.pdf). This international scientific guideline has been adopted for use by the TGA for vaccine evaluation.
Page 20 of the Pfizer COVID-19 vaccine Australian Public Assessment Report (AusPAR) (available at: www.tga.gov.au/sites/default/files/auspar-bnt162b2-mrna-210125.pdf) states that among the 36,523 efficacy evaluable participants who had no evidence of existing or prior SARS-CoV-2 infection (18,198 in the vaccine group and 18,325 in the placebo groups), eight cases of COVID-19 with onset at least seven days after the second dose were observed among vaccine recipients and 162 among placebo recipients.
106. Page 34 of the AusPAR for the Pfizer COVID-19 vaccine states that a limitation of the data submitted to the TGA was that vaccine efficacy against viral transmission has not been addressed. However, a number of studies on the impacts of vaccination on disease transmission have been published in medical literature.
107. The primary efficacy endpoint of the initial trial was to prevent COVID-19 (as compared to the placebo) in subjects who did not have prior evidence of SARS-CoV-2 infection.
As hospitalisation was not a primary outcome of the initial trial, it was not directly assessed in the initial trial and no figures are available.
108. No COVID-19-related deaths were observed.
109. The study of vaccine safety at six months did not identify outcomes of inflammation.
110. The study of vaccine safety at six months did not identify outcomes of clotting.
113. The Department of Health (including the TGA) have not misled the Australian public about the safety and efficacy of the COVID-19 vaccines.
The TGA is not aware of any statements from Dr Albert Bourla, the CEO of Pfizer, claiming the Pfizer vaccine is 100 per cent effective in stopping transmission. On 13 January 2021 and 3 February 2021, Dr Bourla was quoted as saying animal studies show there is significant protection from transferring the virus, but he said at that time that this has not been proven in humans yet (see: www.thejournal.ie/pfizer-ceo-5323949-Jan2021 and www.bbc.com/future/article/20210203-why-vaccinated-people-may-still-be-able-to-spread-covid-19).
