Professor Matthew Snape's study on mixing COVID-19 vaccines further expanded

matthew snape

The study on alternating different COVID-19 vaccines led by St Cross Member of Common Room Professor Matthew Snape has been expanded to young people aged 12 to 16 years. The study is expected to provide crucial information on the range of options for immunising teenagers against COVID-19 in the UK.

Participants can 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 can be enrolled at the time of their second dose. All participants will receive as a second dose 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.

Professor Snape commented:

This is the latest in a series of studies such as COMCOV and COV-Boost that have looked at the ways different COVID-19 vaccines available in the UK can be used to generate the best and most durable immune response, in as safe a manner as possible.

Researchers will assess any side effects and immune system responses to these new combinations of vaccines.

The Com-COV 3 trial seeks to recruit 360 volunteers. All those who are interested in volunteering can find out more about the study at 


Preliminary results from the trials on mixing different COVID-19 vaccines have suggested that mild to moderate reactions are more frequent in administering one dose of the Pfizer/BioNTech vaccine followed by one of the Oxford-AstraZeneca, or vice versa.