Fewer people encouraged to receive the flu jab in Surrey had been vaccinated by the end of 2022 than a year earlier, new figures show.
It comes after flu cases soared during December, with the NHS urging people to get the jab if they have not already.
People aged over 65, clinically at-risk under-65s, pregnant women and two to three year olds are encouraged to get the flu jab as they are at higher risk of complications from the virus.
UK Health Security Agency figures show 288,938 in these groups in Surrey had received the jab up to the end of December.
It meant 66.5% of the 434,283 patients at higher risk from flu registered at GP surgeries in the area were vaccinated by this point – down from 69.6% at the same point last winter.
However, this is above the vaccination level seen before the coronavirus pandemic – 57.2% received the jab by the end of December 2019.
In England, 62.2% of people in higher risk groups had received the jab by the end of last year – down from 64.9% the previous year, but still above pre-pandemic levels of 56.8%.
The fall in the flu vaccination rate comes as flu infections have rocketed throughout the winter.
Across the country, an average of 2,224 beds per day up to January 29 were occupied by a patient suffering from flu.
NHS England said lower vaccination rates were not to blame for the rise in flu numbers, instead attributing it to increased infection in the community following two winters of reduced activity during the pandemic.
Fewer adults in Surrey have received a vaccination this winter, while the number of children vaccinated has also dropped.
Some 54.2% of registered two and three-year-olds in the area had received a flu jab by the end of December, down from 58.2% last winter but above 36.1% in December 2019.
An NHS spokesperson urged pregnant women, parents of young children and those at risk to receive the jab this winter.
Sarah Scobie, deputy director of research at health think tank, the Nuffield Trust, said: "The resurgence of flu this winter, mixed with continuing hospitalisations from Covid-19, other respiratory illnesses and cold weather all fed into intolerable pressure health and care services have seen this winter.
"The uptake of the flu vaccine across several vaccinated groups has been lower than last year but is standing up against pre-pandemic levels."
The latest NHS England figures suggest the winter peak has passed as flu infection rates continue to fall.
Dr Conall Watson, consultant epidemiologist at the UK Health Security Agency, said: "While flu levels continue to fall, winter is not over yet and we need to guard against further surges, and vaccination is our best defence against flu.
"Getting the vaccine when you are pregnant can protect you and your baby against potentially serious complications.
"Young children are also particularly vulnerable to serious illness from flu, so if you or your children are eligible, it’s still not too late to get vaccinated."