Parents of young children are being urged to get them the flu vaccine after a 70% jump in hospital admissions for under-fives with the virus.

Data from the UK Health Security Agency (UKHSA) shows a low uptake of the flu vaccine among two and three-year-olds at the same time as more youngsters are requiring hospital treatment.

The UKHSA said flu is circulating at higher levels than in the past few years. It said young children are particularly vulnerable and can become seriously ill.

Covid restrictions mean most young children have never encountered flu and have no natural immunity to the virus, it said.

Data based on confirmed flu cases in major hospitals shows that, between November 14 and 20, more than 200 children under five are estimated to have been admitted to hospital in England suffering from serious complications caused by flu.

Uptake of the flu vaccine among two-year-olds stands at 31% and 33% among three-year-olds.

These figures are down around 11% compared to the last two years.

GP surgeries are inviting children aged two and three (as of August 31 2022) for the nasal spray vaccination at their practices and parents are encouraged to contact their surgery if they have not received an invite.

All primary school children and some secondary school children are also eligible for the flu nasal spray this year, which is usually given in school.

Dr Conall Watson, consultant epidemiologist at UKHSA, said: “Young children are particularly vulnerable to becoming very poorly from flu.

“For the third week running we have seen hospitalisation rates among children under five jump up, with a 70% increase in just the last week. Over 200 children were hospitalised because of flu in one week.

“Two and three-year-olds can get protection with a free nasal spray vaccine from the NHS.

“Nobody wants their child to get sick so I strongly urge parents to book the vaccine at their GP surgery as soon as possible.”

Anjali and Ben Wildblood from Bristol, who are both NHS consultants, saw their child admitted to hospital with flu.

They said: “Before we were able to get our two-year-old son, Rafa, booked in for a flu vaccine, over the course of a weekend he became very sick, with a high temperature and breathing difficulties.

“He had previously suffered with croup and had been treated with steroids, but this was clearly some other very concerning respiratory problem.

“We took him into A&E, where he was treated and we returned home.

“But his condition got worse again, with a soaring temperature and exhaustion – he had no strength whatsoever and what was so extremely worrying was that he barely had the strength to breathe – every parent’s worst nightmare.

“We returned to A&E and he was admitted to the paediatric intensive care unit (ICU).

“Even as NHS consultants, seeing your child in ICU is a terribly frightening experience.

“He was put under general anaesthetic and intubated, which involved inserting a tube into his throat so he was able to breathe.

“His swab results came back showing he had influenza type A. After two long, agonising days of intubation in ICU, his condition improved and he began to recover. He is now home and doing well.

“No parent wants this for their child or to go through a similar terrible experience.

“We urge other parents of two to three-year-olds to ensure your child gets their flu vaccine as soon as possible.”

New flu figures from the UKHSA will be released on Thursday.