49. The use of pseudouridine in mRNA vaccines was developed as a very recent concept and its long-term effects are unknown. It has however been known for 10 years that the use of pseudo-U causes the stop codons (required to stop adding amino acids to a protein chain) to misfunction, thereby elongating the protein chain and risking translation of the next segment (the 3’UTR) (Karijolich 2011). The effects of this are unknown and cannot be known without specific experiments to address the issue. When did the TGA become aware that the synthetic nucleotide pseudouridine was being used rather than the natural uridine and what testing did it undertake to ensure that it was safe to use? 50. Studies have shown the psuedouridine has a higher translation error rate than uridine. Wasn’t it reckless to roll out the vaccine knowing that? Improving the fidelity of uridine analog incorporation during in vitro transcription | bioRxiv (available at: www.biorxiv.org/content/10.1101/2022.04.12.488100v1)

Question Number: 169
PDR Number: SQ22-000538
Date Submitted: 21/11/2022
Department or Body: Department of Health

Question 49 Both Therapeutic Goods Administration (TGA) provisionally approved Pfizer (COMIRNATY), and Moderna (SPIKEVAX) vaccines consist of N1-methyl-pseudouridine(Ψ) modified (N1- methyl-Ψ) mRNA encoding the SARS-COVID-19 spike protein. N1-methylpseudouridine is a naturally occurring modified nucleotide, that is highly abundant and naturally widespread in cells and its use does not change the features of the mRNA. Pseudouridine or N1-Methyl-Pseudouridine has been used in the development of mRNA therapeutics, including mRNA vaccines, for many years with an aim to enhance RNA stability, antigen expression and adaptive immune responses, and to reduce cytotoxicity of modified mRNA, available at:(https://pubmed.ncbi.nlm.nih.gov/30135514/, https://pubmed.ncbi.nlm.nih.gov/28251988/, https://pubmed.ncbi.nlm.nih.gov/34805188/ and https://pubmed.ncbi.nlm.nih.gov/34075344/). For identical reasons, N1-Methyl-Pseudouridine was used in the Pfizer (COMIRNATY) and Moderna (SPIKEVAX) mRNA vaccines to ensure translation efficiency, stability and safety of the mRNA vaccines. It has also been reported that N1-Methyl-Pseudouridine modified mRNA exhibits higher efficacy (more than 90% of efficacy against COVID-19 symptoms) as compared to the unmodified mRNA vaccines (lower than 50%) encoding the SARS-COVID-19 spike protein (available at: https://pubmed.ncbi.nlm.nih.gov/34145413/). To minimise any misreading risks associated with stop signals (ΨGAΨGA in Pfizer/BioNTech’s vaccine, and ΨGAΨAAΨAG in the Moderna’s vaccine), both mRNA vaccines use consecutive stop codons as a fail-safe mechanism, so that no frameshifting occurs if the first stop codon fails (available at: https://pubmed.ncbi.nlm.nih.gov/34805188/). Based on the knowledge and experience from decades of research and trials with mRNA therapeutics, the COVID-19 vaccine manufacturers were able to design an appropriate dosing regimen and threshold of doses ensuring the proper balance between immune responses and safety of these vaccines. Animal toxicology studies of the Pfizer and Moderna mRNA vaccines at doses 200-times higher than the human dose on a dose/body weight basis have not shown any safety concerns. Question 50 See response to Question 49.