COVID-19 Booster Study in Healthy Adults in Australia

This is a double-blinded, randomised study to determine the safety, reactogenicity, and immunogenicity of a bivalent mRNA Moderna COVID-19 vaccine or a protein-based Novavax COVID-19 vaccine given as a fourth dose in healthy adults in Australia.

Inclusion Criteria:Have received three doses of COVID-19 vaccines at least 6 months earlier.No confirmed SARS-CoV-2 infection on PCR or RAT within the last 3 months.Willing and able to give written informed consent.Aged 18 years or above.Willing to complete the follow-up requirements of the study.Exclusion Criteria:Currently receiving immunosuppressive medication or anti-cancer chemotherapy.Known HIV infection.Congenital immune deficiency syndrome.Received immunoglobulin or other blood products in the three months prior to potential study booster vaccination.Study staff and their relatives.Have a history of a severe allergic reaction to any COVID-19 vaccines or have a medical exemption to receiving further COVID-19 vaccines.Cannot read or understand English.