LONDON, United Kingdom (AFP) — The head of British drug manufacturer AstraZeneca said on Thursday further research was needed on its Covid-19 vaccine after questions emerged over the protection it offers, but the additional testing is unlikely to affect regulatory approval in Europe. AstraZeneca and its partner, the University of Oxford, announced on Monday that it was seeking regulatory approval for the vaccine after it showed average 70 percent effectiveness. That rate jumped to 90 […]