Covid-19, Flu, RSV Surveillance Up Until End Of Week 4

3rd February 2023

COVID-19 surveillance up until end of week 4
Coronavirus (COVID-19) activity shows a mixed picture - with some indicators, most notably hospitalisations and Pillar 2 positivity suggesting a modest increase in activity.

The COVID-19 hospital admission rate for week 4 was 6.61 per 100,000 population, a small increase from 5.94 per 100,000 in the previous week.

Hospital admission rates for COVID-19 are highest in the South East, with a rate of 8.67 per 100,000 population.

Dr Mary Ramsay, Head of Immunisation at the UK Health Security Agency (UKHSA), said:

It's concerning that the recent downward trend in COVID-19 hospitalisations has started to show signs of a reverse this week. Older people are still at the highest risk of being hospitalised for COVID-19, so it's vital those eligible get their autumn/winter booster jab - come forward before Sunday 12 February when the offer comes to an end. It will top up your immunity and keep you protected.

Two variants, CH.1.1 and XBB.1.5, have a growth advantage in the UK and we can expect further increases in transmission and hospitalisations in future weeks.

There are simple actions we can all take to prevent viruses spreading. Washing your hands regularly, catching coughs and sneezes in tissues and if possible letting fresh air into rooms and spaces will all help. If you or your child is unwell please don’t visit vulnerable people, and try to stay at home. If you do have to go out when you’re unwell, consider wearing a face covering which can help prevent you passing viruses on.

Flu surveillance up until end of week 4
Swab positivity for flu* has decreased to 2.7% in week 4, compared to 3.0% in week 3. The highest positivity is seen in those aged 15 to 44 years at 5.8%, an increase from 4.6% in week 3.

Hospital admission rates decreased in the last week and are at low activity levels. ICU/HDU hospital admission rates have also decreased, and are within baseline range of activity levels**.

Flu vaccine uptake is comparable to the previous 2021 to 2022 season in a number of cohorts, with 79.4% of those aged 65 years and over having received their flu vaccine, exceeding the World Health Organization (WHO) target.

For pregnant women, vaccine uptake is 34.6%, and for those aged under 65 years in a clinical risk group, it is 48.4%.

Vaccine uptake in those aged 2 and 3 years (41.6% and 44.3% respectively) is below that seen in the previous 2 seasons, but broadly comparable to the 2018 to 2019 pre-pandemic season.

Rates of in-person contact (meeting with people from outside of the household) for week 4 of 2023 have come back up to rates seen in November to mid-December 2022 (source: UKHSA FluSurvey). UKHSA continues to monitor flu signal as more people return to work and school.

*The percentage of people who test positive among those with symptoms tested at sentinel ‘spotter’ laboratories, reported through the Respiratory Datamart surveillance system.

**Influenza activity bands are set using an international standard method.

Dr Conall Watson, Consultant Epidemiologist at the UKHSA, said:

The NHS has delivered more than 20 million flu vaccines this winter and this will undoubtedly have spared many thousands from severe illness or hospitalisation and saved countless lives.

While flu levels continue to fall, winter is not over yet and we need to guard against further surges. Vaccine uptake among those aged 2 and 3 years is still well below the past 2 seasons and the number of pregnant women not taking up the offer is also a concern.

Vaccination is our best defence against flu. For pregnant women, it can protect both you and your baby against potentially serious complications, and young children are also vulnerable to serious illness. If you or your children are eligible it’s still not too late to get vaccinated.

RSV (respiratory syncytial virus) surveillance up until end of week 4
RSV overall swab positivity* decreased to 2.4%.

The RSV hospitalisation rate increased slightly overall to 1.2 per 100,000.

Learn more about RSV in our blog. https://ukhsa.blog.gov.uk/2022/10/25/5-ways-to-protect-your-under-5s-this-winter/

*Amongst people with symptoms tested at sentinel ‘spotter’ laboratories, reported through the Respiratory Datamart surveillance system