In Scotland, the first study to assess the impact of vaccination on prevention of severe COVID-19 in the community found that four weeks after administration of a first dose, risk of hospitalisation was reduced by up to 85% by the Pfizer/BioNTech vaccine and up to 94% by the Oxford/AstraZeneca vaccine.
Among people aged over 80, combined results from both vaccines showed an 81% reduction in hospitalisation risk four weeks after an initial dose.
Meanwhile, Public Health England (PHE) has reported that data on infection in healthcare workers suggests that a single dose of Pfizer/BioNTech vaccine reduces the risk of catching infection by more than 70% and that after two doses this rises to 85%.
PHE said the findings provided 'strong evidence' that the vaccine could interrupt virus transmission by stopping people from becoming infected - in addition to reducing risk of death or hospitalisation.
PHE added that early data suggested people who did become infected after receiving a single dose of vaccine were 'far less likely to die or be hospitalised'.
It said: 'Overall, hospitalisation and death from COVID-19 will be reduced by over 75% in those who have received a dose of the Pfizer-BioNTech vaccine.'
Although the data published for England covers the Pfizer/BioNTech vaccine only, prime minister Boris Johnson told parliament earlier today that PHE had also found that the Oxford/AstraZeneca vaccine provided a 'good level' of protection.
Lead researcher of the Scottish study and director of the University of Edinburgh’s Usher Institute, Professor Aziz Sheikh, said: 'These results are very encouraging and have given us great reasons to be optimistic for the future. We now have national evidence – across an entire country – that vaccination provides protection against COVID-19 hospitalisations.
'Roll-out of the first vaccine dose now needs to be accelerated globally to help overcome this terrible disease.'
On the England data, PHE head of immunisation Dr Mary Ramsay said: 'This is strong evidence that the Pfizer/BioNTech vaccine is stopping people from getting infected, while also protecting cases against hospitalisation and death. We will see much more data over the coming weeks and months but we should be very encouraged by these initial findings.'
The latest UK data on the COVID-19 vaccination campaign shows that by 21 February, 17.7m people had received a first dose of vaccine - around a quarter of the total population. The government declared last week that it had met its target of vaccinating 15m people by 15 February, covering the vast majority of those in the first four priority cohorts identified by the Joint Committee on Vaccination and Immunisation.