The Oxford vaccine has – like those of Pfizer and Moderna – arrived in record time to a world in desperate need. Since then the Oxford vaccine has been through every stage of trials that would normally take place for a vaccine.
There is a pattern to clinical trials:
- Phase one – the vaccine is tested in a small number of people to check it is safe
- Phase two – safety tests in more people, and to look for signs the vaccine is producing the required response
- Phase three – the big trial, involving thousands of people, to prove it actually protects people
The Oxford vaccine has been through each of those stages, including 30,000 volunteers in the phase three trial, and the team has as much data as any other vaccine trial.