LONDON, United Kingdom (AFP) — AstraZeneca and the University of Oxford on Sunday began new trials to test a modified vaccine against the Beta variant, which first emerged in South Africa. The ‘booster’ vaccine’s trial will involve around 2,250 participants from Britain, South Africa, Brazil and Poland. They include people who have been fully vaccinated with two doses of the original Oxford-AstraZeneca vaccine or an mRNA vaccine such as Pfizer as well as those who […]