Flu positivity jumps to 17.1% as vaccine uptake rates fall short of levels needed to protect the NHS and norovirus levels are the highest in a decade for the time of year.
Government medical experts are urging eligible groups to ensure they book their flu and COVID-19 vaccinations before the December 19 deadline. People are being urged to protect themselves ahead of Christmas amid a recent surge in flu cases.
The latest edition of the UK Health Security Agency’s (UKHSA) surveillance bulletin for COVID-19, influenza (flu), respiratory syncytial virus (RSV) and norovirus (formally the Weekly Winter Briefing) shows that flu positivity in week 49 jumped to 17.1%, compared to 11.6% the previous week.
Flu hospitalizations also rose to 5.53 per 100,000 this week, compared with 3.98 per 100,000 in the previous week’s report.
The national flu vaccination booking system closes on December 19 and with NHS hospitals already managing record levels of flu going into winter, leading doctors, including Chief Medical Officer Professor Chris Whitty, are urging those still eligible for vaccination to book their appointments immediately. After that date, people will only be able to access the flu jab through their GPs and some pharmacies.
The latest figures come as flu and COVID-19 vaccination rates are still not at the levels we need to prevent further increases in admissions. Vaccination is currently at 37% for those in a clinical risk group.
Along with the increases in cases and hospitalizations due to influenza, the latest surveillance data shows that current laboratory reports of norovirus are more than double the 5-season average (see notes). This is the highest number of cases recorded between weeks 47 and 48 (747 laboratory reports) in a decade – since data began reporting this way in 2014.
Norovirus has increased in all regions of England and across all age groups, particularly among those aged over 65. This season, the increase in reports began earlier than usual, with activity between 18 November and 1 December 33.2% higher than in the previous 2-week period.
Susan Hopkins, chief medical adviser at the UKHSA, said:
The threat of an early flu season is looming, along with norovirus rates rising rapidly. With winter vaccine uptake not yet reaching the high levels we’re aiming for in some eligible groups – including healthcare workers – our forecasts for infection rates aren’t getting any brighter.
It’s vital that those eligible get their free flu and COVID-19 vaccinations before Christmas. In just a week’s time, it will be too late to book through the NHS online booking service. Getting the vaccine will avoid putting your seasonal plans at risk – and, more importantly, it will prevent the risk of serious illness and hospitalisation.
Elderly people and people with weakened immune systems are at higher risk of more severe illness from the flu or norovirus. Therefore, if you have flu-like symptoms, diarrhea, or vomiting, avoid visiting people in hospitals and nursing homes to avoid spreading the infection in these settings.
Professor Chris Whitty, Chief Medical Officer, said:
The latest data makes it clear that flu cases are increasing rapidly and we are approaching a severe wave of flu.
Flu can be unpleasant for many and fatal for some. With the festive season approaching, we can still reduce illness, hospitalisations and deaths by increasing vaccination rates – it’s our best defence. Now is the time to get vaccinated, if you’re eligible.
Duncan Burton, Chief Nursing Officer for England, said:
The sharp increase in the number of patients hospitalized with flu compared to last year shows how important it is for anyone eligible to follow the example of millions of others and get vaccinated as soon as possible.
Vaccines are a vital defence against serious illness and hospitalisation and keep you and your family protected, so with the festive period approaching and just a week to go until booking, if you are eligible and have not yet been vaccinated, go online, use the NHS app or call 119 as soon as possible to book an appointment.
Several factors are likely contributing to the unusually high levels of norovirus activity we are seeing at this stage of the season, including changes in diagnostic testing.
However, it is more likely that the emergence of an unusual norovirus genotype, GII.17, is driving the increases. This genotype has become the most commonly detected in England since April 2024, accounting for 63.2% of samples characterised during the 2024/25 season to date.
Previously, GII.4 noroviruses dominated globally, with the GII.4/Sydney/2012 variant persisting as the most frequently detected variant worldwide since winter 2012. There is currently no indication that GII.17 causes more severe disease, but work is ongoing to conduct a more in-depth assessment of severity.
To reduce the spread of norovirus, wash your hands thoroughly with soap and warm water, as alcohol-based hand sanitizers are not effective against the virus. Stay home for at least 48 hours after symptoms have stopped, and disinfect surfaces using a bleach-based cleaner whenever possible.
The UKHSA COVID-19, influenza (flu), RSV and norovirus surveillance bulletin also showed a slight decrease in RSV cases, while COVID-19 continued to circulate at low levels.
Vaccination against RSV is being offered for the first time this year to anyone 28 weeks or more pregnant, as well as people aged 75 to 79.
The NHS website has information about symptoms, how to feel better at home and when to seek medical attention.
The influenza, COVID-19, and RSV week 50 surveillance report and the norovirus surveillance report have been published.
Notes
The 5-season average for norovirus is calculated from the same period during the 5 seasons of 2016/2017, 2017/2018, 2018/2019, 2022/2023 and 2023/2024, excluding years impacted by the COVID-19 pandemic.
