Flu activity is rising across the UK, with health officials warning that the country could be heading towards an earlier flu season after September recorded higher levels of influenza activity than the same period in each of the previous four winters.
The UK Health Security Agency (UKHSA) has published its first weekly winter respiratory virus surveillance report for the 2026 to 2027 season, covering the week from 28 September to 4 October 2026. The report brings together data from GPs, hospitals, laboratories and other surveillance systems to track how respiratory viruses are spreading across England.
According to the latest figures, influenza activity remains at baseline levels, meaning overall activity is still considered very low, but the trend has been moving upwards since August. Flu positivity increased from 5% in the previous week to 6.5% in week 40, while flu hospitalisations were recorded at 1.97 per 100,000 people.
Although these figures remain relatively low, UKHSA said flu activity throughout September was higher than during the same period in all four previous winter seasons. The agency said there are possible signs that the UK could experience an earlier flu season this year, although it is still too early to predict how the season will develop.
The rise in influenza activity is currently being driven largely by young adults. Health officials are continuing to monitor the situation closely as the country moves further into autumn, when respiratory infections typically begin to increase before reaching higher levels during the winter months.
COVID-19 activity also rising
The UKHSA report also shows that COVID-19 activity has increased, although levels remain low. COVID-19 positivity rose from 7.9% to 9.1% during the latest reporting week, while hospitalisations increased from 1.75 to 2.04 per 100,000 people.
COVID-19 intensive care admissions remained very low, increasing slightly from 0.05 to 0.06 per 100,000. UKHSA said the strains currently circulating, including variants known as XFG, remain closely related to strains that have been circulating in the UK for more than a year.
Dr Alex Allen, Consultant Epidemiologist at UKHSA, said the recent increase in COVID-19 activity was not currently accompanied by evidence that the circulating strains were causing more severe illness or spreading more quickly than previous strains.
He said changes in viruses over time are normal and that the autumn COVID-19 vaccine has been designed to provide protection against the strains currently expected to circulate.
UK flu vaccine remains important despite emerging strain changes
One of the issues being closely monitored this winter is the emergence of a drifted influenza A(H1N1) virus. Flu viruses naturally change over time, which is one of the reasons influenza vaccines are reviewed and updated every year.
A recent technical report from the World Health Organization indicated that an A(H1N1) virus recently detected at low levels in parts of Europe and more recently in the UK has undergone genetic changes compared with the A(H1N1) virus component used in this year’s flu vaccine.
However, UKHSA stressed that it is too early to determine whether this drifted virus will become widespread in the UK or what impact the genetic changes could have on vaccine effectiveness.
So far, surveillance data from England shows an approximately equal mix of A(H3N2) and A(H1N1) influenza subtypes. The current flu vaccine contains components designed to protect against the three main influenza groups expected to circulate, including A(H1N1), A(H3N2) and influenza B.
The presence of a drifted strain does not automatically mean that the flu vaccine will stop working. Last winter, a drifted A(H3N2) virus became dominant, but vaccination continued to provide important protection against severe illness.
UKHSA said that despite the earlier start to last year’s flu season and the circulation of the drifted A(H3N2) virus, the overall number of cases during the winter was lower than the previous year, along with lower estimated mortality. Modelling suggested that the vaccination programme in England prevented around 100,000 hospital admissions and 7,000 deaths last winter.
Why flu vaccines are updated every year
Flu vaccines are updated annually because influenza viruses are constantly evolving. The World Health Organization reviews surveillance information from around the world and makes recommendations about which strains should be included in vaccines for the coming season.
This process has to take place several months before the flu season begins so that manufacturers have enough time to produce and distribute vaccines. However, influenza viruses can continue changing after those decisions have been made.
As a result, the viruses circulating during winter may not always be an exact genetic match for the viruses included in the vaccine. Even so, vaccination remains an important tool for reducing the risk of serious illness, hospitalisation and death, particularly among people who are more vulnerable to complications from flu.
Dr Jamie LopezBernal, Consultant Epidemiologist at UKHSA, said the increase in flu activity and the possibility of an early season meant that people eligible for vaccination should consider getting protected now.
He said the vaccine contains components covering all three major types of influenza virus and that it remains difficult to predict whether one strain will dominate the winter or whether several strains will circulate at different times.
Common cold activity begins to fall
The latest surveillance data also provides some reassurance about other respiratory viruses. Rhinovirus, one of the viruses commonly responsible for the common cold, has started to decline following a sharp increase in activity during previous weeks.
Respiratory Syncytial Virus, commonly known as RSV, also remains at baseline levels, with very low levels of the virus currently circulating.
The different trends highlight why health officials continue to monitor a wide range of respiratory viruses rather than focusing on flu or COVID-19 alone. Activity can change quickly as temperatures fall and more people spend time indoors during the autumn and winter months.
What this means for people in the UK
For most people, the latest figures do not suggest that the UK is currently experiencing a major flu or COVID-19 wave. However, the steady increase in flu activity is an early warning that the winter respiratory virus season may be starting sooner than usual.
People who are eligible for a free flu or COVID-19 vaccination are being encouraged to take up the offer rather than waiting until respiratory virus activity becomes significantly higher. The NHS provides vaccination to eligible groups because they face a greater risk of serious complications if they become infected.
Eligible people can check their vaccination status and book through the NHS App, online, through their GP practice or through participating local pharmacies.
For Nigerians and other African communities living across the UK, the latest respiratory virus figures are particularly relevant as families begin preparing for the colder months. Many people in the diaspora balance work, university, childcare and busy family schedules, while some also live with older relatives or other family members who may be more vulnerable to serious respiratory infections. Understanding when flu and COVID-19 activity begins to rise can therefore help households make sensible decisions about vaccination, winter health and protecting vulnerable relatives.
At Chijos News, we will continue tracking UK health developments that have a direct impact on Nigerians and other diaspora communities, particularly issues involving the NHS, vaccination, cost of living, immigration, work, family life and access to essential services. For Nigerians building their lives in Britain, knowing what is changing across the UK is not just about following the news. It is about having the information needed to make informed decisions for yourself and your family.