Imperial College London conducted a Real-Time Assessment of Community Transmission (REACT-1) analysis, based on more than 100,000 home swab tests performed between May 20 and June 7, estimates that the 0.15 percent of people have the deadly virus, or about 1,670.
It found that the link between infections, hospitalizations and deaths had weakened since February, but since the end of April, the trend has been reversed in the case of hospitalizations.
“We found strong evidence of an exponential growth in infection from late May to early June in the REACT-1 study, with a doubling time of 11 days on average for England,” said Professor Paul Elliott, Director of the REACT program. from the Imperial School of Public Health.
“These data are consistent with the Delta variant becoming dominant and show the importance of continuing to monitor infection rates and variants of concern in the community,” he said.
The findings come days after UK Prime Minister Boris Johnson announced a month-long delay to end lockdown restrictions, citing the growing number of cases of the Delta variant, first identified in India. .
“These findings highlight the harsh context in which we made the difficult decision to delay step 4 of the roadmap out of the lockdown,” said UK Health Secretary Matt Hancock.
“Cases are now increasing, but thanks to our incredible vaccination program and our improved response package, which includes surge testing, we have the tools to slow the spread of this virus. We all need to keep our nerves a little longer as our vaccine launch continues and I urge everyone to continue to observe hands, face, space, and fresh air, and make sure to receive both doses of the vaccine for the best protection. possible, ”he said. .
Scientists in the Imperial study estimate that the reproduction number, or R number, of the deadly virus is now well above one in 1.44, meaning that 10 infected people would pass the virus to 14 others on average, resulting in in a rapidly growing epidemic.
Most infections occur in children and young adults, but they are increasing in older people as well, increasing at a similar rate in those over 50 and under 50.
“Even though we are seeing the higher prevalence of infection in younger people who are less susceptible to COVID-19, if this growth continues, it will increase infections in older and more vulnerable people, as vaccines are not 100% effective and not everyone has been fully vaccinated, ”said Professor Steven Riley, professor of infectious disease dynamics at Imperial.
“This would lead to more hospitalizations and deaths, and runs the risk of overburdening the NHS, so it is vital that people accept their offer of vaccines and continue to abide by the rules,” he said.
The REACT-1 study is an ongoing pandemic study, led by Imperial and conducted in partnership with Ipsos MORI, that tracks current coronavirus infections in the community by testing randomly selected people each month for approximately a two-week period. .
For this last round, 108,911 people were sampled at home and their samples were analyzed using PCR tests; 135 of them were positive, of which the vast majority (about 90 percent) were the Delta variant at the end of the study round.
This, he notes, is consistent with data from Public Health England (PHE) reporting that the variant accounts for 90 percent of infections.
In the study’s previous testing round, infection patterns were fairly similar across the country, but the most recent data showed substantial regional variation.
The highest prevalence was found in the Northwest at 0.26 percent, down from 0.11 percent in the previous round, while the Southwest had the lowest at 0.05 percent, slightly below 0. , 07 percent.
The study has also been tracking the relationship between infections, hospital admissions, and deaths in different age groups.
Since February, the link between infections, hospitalizations and deaths has weakened in people aged 65 and over, while there has been a recent reversal of these trends for those under 65, probably reflecting lower vaccination rates in this group.