Question Number: 243
PDR Number: SQ22-000613
Date Submitted: 21/11/2022
Department or Body: Department of Health

130 Instructions submitted by Pfizer to invert the vial gently 10 times ensures that the end user mixes the diluted vaccine appropriately. The additional two inversions, i.e.: 10 instead of eight, safeguards that the end user has mixed the vaccine thoroughly, and thereby reducing human error, to ensure a uniform dose. Pfizer submitted initial studies investigating the use of multi-dose vials intended to deliver an initial five doses from one vial. The studies demonstrated that the intended injection volume per average dose can be delivered over five separate injections using standard syringe and needle assemblies. This was confirmed through testing by Therapeutic Goods Administration laboratory scientists. Additionally, the safety of the vial (container closure system) was assessed and found to be in accordance with international pharmacopeial standards and acceptable for use for the mRNA vaccine. 133 Even though the Moderna and Pfizer COVID-19 vaccines are both mRNA vaccines and work in a similar manner to enhance immunity against the SARS-CoV-2 (the virus that cause COVID-19), each have individual formulations and utilise different lipid nanoparticles which act as protectants and carriers of the mRNA as well as doses of the mRNA. The higher dose of mRNA in the Moderna vaccine was chosen by the sponsor but in discussion with major regulators such as the US FDA. Some studies have shown that the higher dose in this vaccine may provide a greater immune response than the Pfizer vaccine (e.g. higher levels of neutralising antibodies), but it also is accompanies with higher reactogenicity.