Coronavirus-related hospital admissions have dropped at Rotherham Doncaster and South Humber Trust a year on from the start of the vaccine rollout, figures show.
However, the Government is urging caution amid uncertainty over the impact that the newly discovered Omicron variant will have on the number of new coronavirus cases, as hospitals also deal with winter pressures.
More than 400 cases of the new variant have now been identified across the UK, but the Government cannot “say for certain” whether it will escape Covid vaccines, or how severe a disease it will cause.
NHS England data shows 10 people were admitted to hospital with Covid-19 or were diagnosed in hospital with coronavirus for the first time at Rotherham Doncaster and South Humber NHS Foundation Trust between November 1 and November 28 – the latest available data.
This was 22 fewer than 32 in the same period in 2020, just before the vaccine rollout began and England was in its second full lockdown.
Across England, 19,000 people were admitted or diagnosed with Covid for the first time in hospital in November – a 48% decrease compared to the same month in 2020.
NHS patient Margaret Keenan was the first person in the world to receive an approved Covid-19 jab on December 8 last year in Coventry.
Since then, around 39 million people across England have received both doses – 81% of those eligible – with more than 17 million having also received a booster jab – more than a third of all people aged 12 and over.
In its latest Covid-19 vaccine surveillance report, the UK Health Security Agency said all three vaccines approved for use in the UK – AstraZeneca, Pfizer and Moderna – were showing to be effective against hospitalisation in over 90% of cases where people were infected with the currently dominant Delta variant.
It said: "In most groups there is relatively limited waning of protection against hospitalisation over a period of at least five months after the second dose.
"Greater waning appears to occur among those in clinical risk groups."
In response to the emergence of the Omicron variant, the Government is expanding the booster programme to all over-18s as well as halving the gap between doses.
Although it is not yet known whether existing vaccines are less effective against the Omicron variant, the Department for Health and Social Care said it is unlikely they offer no effectiveness against serious disease.
Professor Mark Woolhouse, member of the Scientific Pandemic Influenza Group on Modelling, said coronavirus jabs have worked well so far.
He said: “Against the Delta variant, which is a different variant, the booster vaccinations have turned out to be very effective – well into the 90% protection against infection, but also against disease and putting people in hospital.
“So even if the vaccines were slightly less effective against Omicron they would still be very good.”
The Government is deploying 400 military personnel and creating pop-up sites and additional hospital hubs to deliver the vaccines.
Labour leader Sir Keir Starmer is calling on those who are eligible for the jab but unwilling to "consider the impact of their decision, think again, and get vaccinated."
Health and Social Care Secretary Sajid Javid said with Christmas fast approaching, it is crucial that those eligible get their booster jab ahead of meeting up with loved ones.