227. The virus needs two enzymes to cross the membrane whereas the vaccine needs none as it relies in transfection – is that correct? If that is the case, then is it fair to say the vaccine is more infectious, isn’t it? 286. Aren’t nasal sprays better than vaccines for respiratory viruses that enter through the airways? 287. What steps or tests has the health department taken to ensure that immune imprinting or antibody dependent enhancement is not occurring with repeated booster shots. This is a well-known phenomenon, dengue fever being a prime example. It was highlighted by Pfizer as a potential risk. Furthermore, why isn’t this potential risk highlighted in any Covid booster advertising? 290. Is the overuse of booster and the use of a stronger spike protein causing the immune system to downregulate in other areas leading to cancer and diabetes?

Question Number: 269
PDR Number: SQ22-000640
Date Submitted: 21/11/2022
Department or Body: Department of Health

Question 227 The vaccine mRNA encapsulated in lipid nanoparticles (LNPs) enters into cells without the assistance of enzymes. The COVID-19 vaccines are designed to trigger immunity against SARS-CoV-2 virus. The vaccines are not infectious themselves given that the spike proteins expressed following vaccination is not a pathogen. As indicated in answers to other questions, the vaccine mRNA is broken down rapidly after it is released from LNPs and rapidly eliminated from tissues with half-lives of 15-60 ours except for the injection site muscle, lymph nodes and spleen (detectable five days after dosing).

Question 286 There has been extensive research on nasal spray vaccines against respiratory viruses. Nasal spray vaccines against COVID-19 are approved in some countries, particularly developing countries (available at: www.nature.com/articles/d41586-022-02851-0). However, there is no robust clinical data available for assessing their efficacy and safety, and several have not met with success in trials. Therapeutic Goods Administration (TGA) have not received applications for any nasal vaccines against COVID-19. Nasal sprays may refer to a product designed to act as a barrier in the nasal cavity or to a nasally administered vaccine. However, neither are currently registered on the Australian Register of Therapeutic Goods (ARTG) for the prevention of COVID-19.

Question 287 All therapeutic goods are associated with benefits and risks (including COVID-19 vaccines). The benefit-risk balance remains positive for the currently registered COVID-19 vaccines, and the benefits significantly outweigh the potential risks of immune imprinting. Immune imprinting may potentially occur in response to any antigen, including SARS?CoV?2 or influenza virus. This can be in response to natural infection, vaccination, or booster vaccination. For SARS?CoV?2, current evidence indicates that immune imprinting likely only affects the humoral immune response against SARS-CoV-2 variants whilst preserving T and B cell responses, including vaccine/booster-induced cross-reactive responses against SARS-CoV-2 variants. This indicates ongoing protection against SARS-CoV-2 variants, including longer-term protection. Furthermore, this effect may be supported further by vaccines or boosters targeting circulating variants specifically, in particular in the context of a large amount of shared epitopes.

Question 290 There is no evidence of immunosuppression from booster doses of vaccines. There are no reports of immunosuppression from annual booster vaccination with influenza vaccines. There is no clinical evidence that the use of a COVID-19 booster vaccine at any of the recommended doses is causing the immune system to downregulate leading to cancer or diabetes.