Health officials have raised concerns over a drop in the uptake of the flu vaccine after it emerged at least 18,000 deaths were associated with the illness over the past two years.
Eligible people are now being urged to get vaccinated to protect themselves from winter viruses.
There was a drop in people having the jab across all eligible groups in England last year, according to the UK Health Security Agency (UKHSA).
One in four (41.4%) people in clinical risk groups were vaccinated last winter compared to 49.1% in the previous year.
Some 32.1% of pregnant women also had the jab, down from 35%, while uptake among two and three-year-olds was around 44%, down from 42.3% and 45.1% respectively.
Uptake among older people remained high but still declined year on year, falling to 77.8% from 79.9% in those 65 and over.
Dr Gayatri Amirthalingam, deputy director of immunisation at UKHSA, said: “As winter approaches we see many dangerous viruses circulating in our communities including flu, which can tragically kill thousands of people every year.
“Getting vaccinated ahead of winter is by far your best defence.
“If you’re pregnant or have certain long-term health conditions you are at greater risk of getting seriously ill. Older people and young infants with flu are also much more likely to get hospitalised.”
Millions of people were invited to book flu jabs and Covid-19 boosters from September 23, with appointments starting from October 3.
Those eligible include over 65s, people in clinical risk groups, patients in long-stay residential homes and frontline social care workers.
Over 65s, care home residents and staff, frontline health and social care workers and people in clinical risk groups, including pregnant women, have been offered a Covid booster.
A new vaccine for respiratory syncytial virus (RSV) was also rolled out for the first time in the UK last month, with pregnant women and adults aged 75-79 invited to book.
Steve Russell, national director for vaccinations and screening at NHS England, added: “Today’s data showing there were almost 20,000 deaths associated with flu over the past two winters is a shocking reminder that this is a seriously dangerous virus, and I urge those who are eligible to book their vaccine appointment as soon as they can as it is our best way of protecting those who are vulnerable as winter approaches.”
A mother whose then four-year-old was hospitalised with flu shared her experience.
Maryam Sheiakh, from Manchester, took her daughter Saffy to Royal Manchester Children’s Hospital with a severe cough and high temperature.
Saffy Sheiakh was hospitalised with flu aged four (Maryam Sheiakh/PA)
She was later referred to a high-dependency unit and required oxygen.
“I was seriously concerned we might lose Saffy,” Ms Sheiakh said. “I honestly thought she might die from this. I was so distraught watching her struggling to breathe day after day, worried about her breathing difficulties and getting oxygen to the brain – would she be the same little girl before she got ill?”
Saffy, now six, made a full recovery. Her mother has urged all parents to vaccinate their children.
“Just go and get it, don’t take the risk,” Ms Sheiakh added. “No parent wants to watch their child suffer like we did with Saffy.”
In a bid to address issues around jab uptake, UKHSA has launched a new campaign with the Department of Health and Social Care (DHSC) and the NHS.
Get Winter Strong will run for 10 weeks on TV, radio and social media channels, urging those eligible to get vaccinated.
Health minister Andrew Gwynne said: “I encourage everyone who is eligible to get their flu, Covid-19 and RSV vaccinations as soon as possible. They are without doubt the best way to protect yourself from these viruses that can cause serious harm.”