Watch Stacey Poole's report here
The world's first vaccine alternating study launches today in Southampton and in Oxford. The study which is backed by £7 million of government funding will recruit 800 participants across seven UK sites.
The current programme of two doses of the same vaccine over twelve weeks remains unchanged.
Southampton is set to help deliver the vaccine study looking at using different vaccines for first and second doses, and varying the time between doses.
Researchers will compare the immune response when using different intervals between the first and second dose when a combination of vaccines are used compared to when the same vaccine is used.
The study will be run at the NIHR Southampton Clinical Research Facility (CRF) and University of Oxford's Centre for Clinical Vaccinology and Tropical Medicine.
Both sites are looking to recruit 100 volunteers, aged 50-years-old and above, to join a further 600 volunteers at 6 other sites nationally.
Anyone who has received either the Pfizer or AstraZeneca vaccination as part of the UK-wide delivery plan will not be affected by this study.
Professor Saul Faust, Director of the NIHR Southampton Clinical Research Facility, said: "We're really keen to hear from those between 50 and 70 years of age, especially those from a black or Asian background. No one taking part will receive a placebo, or dummy, dose - all receive two doses of the currently approved vaccines used by the NHS."
The study will initially have eight different arms, testing eight different combinations, but more products may be added:
Oxford/AstraZeneca and Oxford/AstraZeneca - 28 days apart
Oxford/AstraZeneca and Oxford/AstraZeneca - 12 weeks apart - as a control group
Pfizer/BioNTech and Pfizer/BioNTech - 28 days apart
Pfizer/BioNTech and Pfizer/BioNTech - 12 weeks apart - as a control group
Oxford/AstraZeneca and Pfizer/BioNTech - 28 days apart
Oxford/AstraZeneca and Pfizer/BioNTech - 12 weeks apart
Pfizer/BioNTech and Oxford/AstraZeneca - 28 days apart
Pfizer/BioNTech and Oxford/AstraZeneca - 12 weeks apart
The study will last for 13 months, and those interested in volunteering at either Southampton or Oxford can find out more here.