Flu levels are continuing to rise in England, with some young children already needing intensive care.

Rates are estimated to be highest among five to 14 year-olds, with 12.0% of laboratory samples from this age group testing positive, according to new figures from the UK Health Security Agency (UKHSA).

Some 5.2% of samples from all age groups tested positive in the week to October 23, up from 4.8% in the previous week.

Hospital admission rates are highest for those under the age of five, at 3.2 per 100,000 people, up week-on-week from 2.6.

Overall levels of flu are still low, meaning it is too early to predict how big the wave of infections will be.

But vaccination uptake among very young children is down on this point last year, with an estimated 16% of two-year-olds having received the flu vaccine, along with 17% of three-year-olds.

All two and three-year-olds are eligible for a flu nasal spray vaccine, which will be offered by their local GP.

In total around 33 million people in England can get a free flu vaccine this year, including everyone aged 50 and over, all primary-age children and some secondary-age children.

The vaccine is also being offered to pregnant women, people in care homes, frontline health and social care staff, carers, those aged six to 49 with a specified health condition, and household contacts of people with weakened immune systems.

Dr Conall Watson, UKHSA consultant epidemiologist, said: “Hospital admission rates for flu have increased in recent weeks and remain highest in those under five.

“Already this year a small number of young children have needed intensive care.

“Please book your pre-schooler in for flu vaccine at your GP surgery as soon as you can.

“Flu nasal spray vaccine is also currently being offered to all primary school children and will be available for some secondary school years later this season.”

Vaccine uptake among primary school-age children stood at 3.9% at the end of September – compared with 5.4% at the same point last year, the UKHSA said.

Many of the same groups of people who are eligible this year for a flu vaccination are also entitled to receive a fresh booster of Covid-19 vaccine.

Dr Nikki Kanani, NHS England deputy vaccination programme lead and local GP, said: “On Wednesday I joined over 11 million people who have got their autumn booster ahead of winter alongside my flu vaccination.

“I’ve seen first-hand the enthusiasm from the public for both vaccines this winter, and with over 9,000 Covid positive patients currently in hospital, its vital people come forward without delay.

“Everybody who is eligible for either an autumn booster or flu vaccine can now get one, so come forward today to give yourself the best protection on offer this winter.”