This will provide the JCVI with information crucial to informing their advice about immunising teenagers in the UK.’Participants can either receive two COVID-19 vaccine doses in the study, in which case their first dose will be the Pfizer COVID-19 vaccine. Alternatively, those who have already received a dose of the Pfizer COVID-19 vaccine through the NHS can be enrolled at the time of their second dose. All participants will be randomly allocated at the time of the second dose to receive either a full dose or half dose of the Pfizer-BioNTech vaccine, a full dose of the Novavax vaccine or a half dose of the Moderna vaccine. In May, researchers reported preliminary Com-COV data revealing more frequent mild to moderate reactions in mixed schedules compared to standard schedules, however, these were short-lived in duration. In April, the researchers expanded the programme to include the Moderna and Novavax vaccines in a new study.
