One vaccine dosage reduces the risk of coronavirus hospitalisation by three-quarters, according to a recent Public Health England (PHE) study.
The observational study focused on the Pfizer and AstraZeneca vaccinations and looked at their effectiveness against the Delta variation, which was initially discovered in India, reports The Independent.
More information was available because these vaccines have been widely used in the UK since January, as opposed to the Moderna vaccine, which was only introduced on 13 April.
The study looked at how efficient the vaccines were at preventing persons from becoming symptomatic with Covid and how successful they were at preventing hospitalisations caused by the virus.
It was discovered that one dose of vaccine against symptomatic Covid was 49% effective in reducing the risk of catching symptomatic Covid with the Alpha (Kent) variety, but only 31% effective against the more contagious Delta variation.
With two doses, the vaccines were more than 80 per cent effective in preventing symptomatic illness with coronavirus, with a slightly higher potency against the Alpha variant (88 per cent compared with 80 per cent).
The study also found that one dose of either vaccine substantially reduced the risk of hospitalisation by at least 75 per cent against either variant.
After two doses, the risk of being hospitalised with coronavirus was reduced by more than 92 per cent the study found.
The study's authors concluded: "After two doses of either vaccine there were only modest differences in vaccine effectiveness with the B.1.617.2 (Delta) variant. Absolute differences in vaccine effectiveness were more marked with dose one.
"This would support maximising vaccine uptake with two doses among vulnerable groups."
The research was included in PHE's technical briefing on 18 June, as the case count of the now-dominant Delta soared to 75,953 cases across the UK, growing by 33,630 or 78 per cent since last week.
As of 14 June, 806 people in England had been admitted to hospital with the variant.
The release of this data also follows the government's decision to delay the easing of lockdown restrictions by a month, in order to increase vaccinations across the UK, with a particular focus on second doses for older and clinically vulnerable adults.
All adults in England have now been invited to book a coronavirus jab.