The findings from Imperial College London and Ipsos MORI, covering 8 March to 31 March 2022 (round 19 of the study), show that prevalence in England during this period was 6.37%.
This is the highest recorded figure since the beginning of the study in May 2020 and significantly up on the 2.88% recorded in round 18 (8 February to 1 March 2022).
This means that during the period in which swabs were collected, approximately 1 in 16 people were infected with the virus.
Dame Jenny Harries, Chief Executive of the UK Health Security Agency (UKHSA), said:
These latest study results are another reminder that the pandemic is not over, and there is still a real risk to many of us catching COVID-19 with infection rates so high.
That is why it is sensible to wear a mask in crowded, enclosed spaces, keep indoor spaces ventilated and stay away from others if you have any symptoms of a respiratory illness, including COVID-19.
Vaccination continues to prevent a high number of cases resulting in severe disease, hospitalisation and death and remains the best way to protect us all.
If you have not yet come forward for your primary or booster vaccine I would urge you to do so straight away - the NHS vaccine programme is there to help you and the sooner you are vaccinated the sooner you and your family and friends will be protected.
I'd like to thank each and every REACT participant for contributing to what has been a vital study throughout the course of the pandemic in giving us insight into how COVID-19 has impacted the country.
Health and Social Care Secretary Sajid Javid said:
Thanks to our plan to tackle COVID-19, we are leading the way in learning to live with the virus. We have made huge progress due to the success of our world-leading vaccination programme, access to antivirals for vulnerable people and increased scientific and public understanding about how to manage risk.
Despite high infection rates, the population now has much stronger protection against COVID-19 than at any other point in the pandemic.
Vaccines remain our best defence and we are now offering spring boosters to the elderly, care home residents and the most vulnerable - so please come forward to protect yourself, your family, and your community, and continue to follow public health guidance if you test positive.
Professor Paul Elliott, director of the REACT programme from Imperial's School of Public Health, said:
These trends are concerning since when a very high number of people are infected, this may lead to more people becoming seriously ill and needing to go to hospital.
Although restrictions have ended, I would urge people to still behave cautiously to help protect others who might be vulnerable and avoid contact with other people if you have symptoms. This will help to slow the spread of the virus and lessen its impact on the NHS and our lives more broadly as we enter this next phase of the epidemic.
Kelly Beaver, CEO at Ipsos MORI, said:
The high prevalence of COVID-19 the REACT study has found in the population highlights the need for continued vigilance as, as a society, we learn to live with COVID-19.
Over the course of REACT over 3.5 million people in England have taken part and have contributed to the enormous success of the study. We'd like to thank all of those people who took part over the last 2 years for helping provide this invaluable resource to government.
The main findings from the report are as follows:
There were 6,902 positives from 109,181 swabs in round 19, giving an overall weighted prevalence of 6.37%. This is an increase in weighted prevalence of over 2-fold from round 18, where the figure stood at 2.88%.
Weighted prevalence was very high and increased between rounds 18 and 19 in all age brackets. Prevalence was highest in 5 to 11-year olds at 8.81%, nearly double the rate reported in the same age bracket in round 18.
There was a possible decrease in prevalence within round 19 in those aged 5 to 17 and a possible plateauing prevalence in those aged 18 to 35 and those aged 35 to 54, but a within-round increasing trend in those aged 55 and over.
Overall, the analyses showed a within-round reproductive number (R) of 1.10 in those aged 18 to 34 years, 1.04 in those aged 35 to 54 years and 1.12 in those aged 55 and over.
A total of 3,383 viral lineages were determined from the 4,038 positive samples up to 22 March; 89.7% (3,035) of these lineages corresponded to BA.2 or its sub-lineages, and 10.2% (346) to BA.1 and its sub-lineages.
There was just one case of the AY.4 Delta sub-lineage detected and one case of BA.3, while there was additional detection of both the XE and XL recombinants.
Exponential models estimated a daily growth advantage for BA.2 of 0.11 compared to all other Omicron sub-lineages. These models estimate that as of 22 March 2022 the proportion of BA.2 in all recorded infections across the country was 94.7%.
Weighted prevalence in round 19 was higher in all regions of the country compared to round 18, ranging from 5.28% in the West Midlands to 8.13% in the South West. The recorded prevalence in the next highest region, the East of England, was 7.17%.
At a lower-tier local authority level, of the 10 highest smoothed estimates of prevalence based on a nearest neighbour method, 7 were in the South West - Plymouth, Cornwall, South Hams, Torridge, Torbay, West Devon and Exeter. The other 3 highest - Braintree, Colchester and Maldon - were in the East of England.
The rate of prevalence among those who had been in contact with a positive case stood at 17.8% compared to 4.00% in those without such contact.
Among those who tested positive and reported on symptoms, 26.7% reported no symptoms in round 19 compared to 28.6% in round 18.
Over 109,000 volunteers in England took part in the study to examine the levels of COVID-19 in the general population between 8 March and 31 March.
