Around four in every five adults in Central Bedfordshire have been vaccinated against Covid-19, a meeting heard.
The 80 per cent figure is short of the 90 per cent target, Central Bedfordshire Council's social care, health and housing overview and scrutiny committee was told.
But work continues to persuade reluctant residents in all eligible sections of the population, according to CBC director of public health Celia Shohet.
"We're seeing cases start to increase again," she warned. "That's not great. This is mainly because of the return to school and some recent large scale mass events, which have driven infections.
"And there were changes to Covid regulations in mid-August. We're seeing slight increases in hospital admissions as well.
"But the impact on overall admissions and deaths remains much lower than during the second wave.
"That's because of a successful vaccination campaign and a quite phenomenal uptake of vaccine in Central Bedfordshire," she explained.
"We're still not quite where we want to be at 90 per cent of all cohorts having both doses. It's approaching about 80 per cent for 18 plus, so that's pretty good for the two doses.
"Although people are vaccinated, you can still catch and transmit Covid. But the consequences are significantly lower if you become infected, so testing is still really important.
"I see every day the number of people in hospital and particularly in critical care with Covid, and those figures are going in the wrong direction.
"I don't think any of us are complacent," she added. "Any death is a tragedy. If we compare cases today with this time last year they're 30 times higher, without huge numbers in hospital thankfully.
"But hospitals are overwhelmed generally with demand, so the more we do to avoid any of this being driven by Covid the better."
Liberal Democrat Houghton Hall councillor Susan Goodchild wondered about the impact of vaccine hesitancy.
Ms Shohet said: "We've been doing a lot of work on this. One area is women concerned about fertility issues. About eight to ten per cent of people who don't have the vaccine are needle phobic.
"Some people think they've had Covid or it's not an issue and they don't need to have it. We're trying to dispel that myth.
"Others are worried about the short-term side effects or say they felt rotten after their vaccination. Some have been vaccinated overseas and those don't show on our system here."
Independent Biggleswade South councillor Hayley Whitaker asked about the process within schools, saying: "The rules in schools have changed completely. There'll be no sending children home unless as a last resort."
The director of public health replied: "All of us are just getting used to some of those changes.
"If children test positive in school they must go home for the entire period of isolation. But their classmates and staff, if fully vaccinated, don't need to self-isolate.
"There are extra measures we could put in place if schools have five cases in ten days, or ten per cent of pupils who test positive in that period, or if a child is hospitalised through being Covid positive.
"We're always balancing the need to reduce transmission against keeping children in school and in education."
Conservative Sandy councillor Tracey Stock said: "I'm aware the NHS has written to young adults who haven't been vaccinated encouraging them and the details are within the letter on how they can access a local vaccine."