Data from the rollout of AstraZeneca's Covid-19 vaccine shows one dose of the shot results in 80 per cent less risk of death from the disease, Public Health England said on Monday. It also said protection against death from the Pfizer-BioNTech vaccine rises from approximately 80 per cent after one dose to 97 per cent after two doses in its new analysis.People who had a single dose of AstraZeneca vaccine were 55 per cent protected against death, with a figure of 44 per cent protection for a single dose of Pfizer, compared to unvaccinated people.Watch the video for more information.