More than 14,500 flu-associated deaths are estimated to have occurred in England during the 2022/23 season, the highest number since 2017/18, figures show.
A further 5500 deaths are likely to be linked to extreme cold weather – the highest level for a decade.
Health services faced a hat-trick of pressures last winter, with a fresh surge of COVID-19 infections coinciding with the first major wave of flu since the start of the pandemic plus a period of very cold temperatures.
The impact of the flu was greater due to "lower population immunity", with little or no flu circulating during the previous two winters when COVID control measures were in place, experts said. Flu vaccines "helped prevent a much worse winter", however.
An estimated 14,623 flu-associated deaths took place in England during the 2022/23 season, according to the UK Health Security Agency (UKHSA). This was the highest number since 22,419 in the 2017/18 season. Each season runs from week 40 of one year to week 20 the next – in the most recent instance, from the week beginning 3 October 2022 to the week ending 21 May 2023.
The highest number of deaths associated with flu in the last decade was 29,965, in 2014/15.
Majority of Deaths in People 65 and Older
Of the 14,623 flu deaths estimated to have occurred in the 2022/23 season, 12,546 (86%) were among people aged 65 and over. The proportion was even higher for deaths linked to cold weather, with 5136 (93%) of the estimated total of 5,533 being among over-65s.
Dr Conall Watson, UKHSA lead flu epidemiologist, said: "Flu returned at scale last winter after being locked out by COVID-19 control measures.
"Lower population immunity following flu's absence played a part in the season starting relatively early and led to lots of people catching flu in a short time-frame," she said, explaining why the number of cases was higher last winter. "We have clear evidence that the protection from last season's vaccine programme helped prevent a much worse winter. Plans for the delivery of this winter's vaccine programme are well under way and we strongly advise all those eligible to take up the offer of vaccination this autumn."
Most Deaths Due to Extreme Cold in 10 Years
The cold snap last December saw heavy snow fall across many parts of England in the middle of the month, closing motorways and airports, blocking roads and damaging power lines. Temperatures were close to freezing for several days, with some areas struggling to reach 0°C, such as Wallington in Northumberland, which saw a peak of -5.9°C on 12 December.
The UKHSA estimate of 5533 deaths linked to the cold weather is based on the three coldest weeks during the 2022/23 season, when the mean central England temperature was below 3°C. It is the highest total on this measure since 5748 deaths associated with cold weather in 2012/13.
The UKHSA report notes that, were its threshold for cold weather changed to include more weeks, "it is likely more deaths would be attributed to severe cold weather; however, the aim was to look at extreme cold weather only".
An estimated 10,345 deaths associated with COVID-19 occurred in England during the 2022/23 season, compared with 25,971 in 2021/22. Deaths linked to COVID-19, flu, or extreme cold weather are all classed as "excess deaths", because they are in addition to the average number of deaths typically occurring at the time of year.
The UKHSA estimates there were a total of 33,528 excess deaths in England during the 2022/23 season, including deaths not linked to any of the three main factors. This figure is up from 20,806 in 2021/22.