The Phase II/III trial, sponsored and led by AstraZeneca, will recruit approximately 2,250 participants across UK, South Africa, Brazil and Poland.
The study aims to assess the immune response to the Beta variant of concern with the new vaccine – for use potentially in combination with the current Oxford-AstraZeneca vaccine – as well as to better understand the disease and associated health problems.
Initial data from the trial is expected later this year and, once available, will be submitted to regulators for assessment as a next-generation booster vaccine and through an expedited regulatory pathway.
AZD2816 will be administered to individuals who have previously been fully vaccinated with two doses of the original Oxford-AstraZeneca vaccine or an mRNA vaccine, at least three months after their last injection.
In non-vaccinated individuals, AZD2816 will be given as two doses, four or twelve weeks apart, or given as a second dose following a first dose of the original Oxford-AstraZeneca vaccine four weeks apart.
Adenoviral vector platform
The new vaccine, known as AZD2816, has been designed using the same adenoviral vector platform as that used in the development of the original Oxford-AstraZeneca jab but with minor genetic alterations to the spike protein based on the Beta variant.
Professor Sir Andrew J Pollard, chief investigator and director of the Oxford Vaccine Group at the University of Oxford, said: “Testing booster doses of existing vaccines and new variant vaccines is important to ensure we are best prepared to stay ahead of the pandemic coronavirus, should their use be needed.”
Also weighing in on the trial was Dr Maheshi Ramasamy, principal investigator at the Oxford Vaccine Group: “The UK vaccine roll out program has been incredibly successful at preventing hospitalizations and deaths, but we don’t know how long protection lasts. This study will provide vital evidence on whether further doses including “tweaks” against new virus variants may be needed in the future.”