The prevalence of coronavirus cases in England fell by around 60% from February to March. Recent data suggests that the decline is “flattening out,” according to the researchers.
Experts found that the infection rate fell in all age groups and regions during these two months. The numbers also suggest that the introduction of the vaccine could “break” the link between infections, deaths and hospital admissions.
According to the latest round of the Real-Time Assessment of Community Transmission (React-1) study, an average of one in 500 people was infected with the virus in March.
The researchers found that the prevalence of the virus “fell sharply” in the southeast and London from February to March, but the southern part of Yorkshire and parts of the east still have “persistent areas of higher prevalence” of the Midlands and virus the northwest.
To date, more than 1.5 million people have provided swabs to the React-1 study for experts to assess infection rates across the country.
The 10th round of testing was conducted between March 11th and March 30th with 140,844 swabs collected, giving 227 positive results.
This is compared to 689 positive results from 165,456 swabs from February 4th to 23rd.
The researchers’ results, which are to be published as a form, were presented in a briefing to journalists on Wednesday.
- The infection rate in the community was 0.20% in March – after 0.49% in February and 1.57% in January.
- While Covid prevalence declined on average overall throughout February and March, researchers observed that last month’s data indicated that this had flattened out.
- Using the March data alone, the reproductive number (R) – the average number of people to whom an infected person is likely to pass the disease on – has been estimated to be 1.
- The Covid-19 prevalence decreased in all age groups between February and March, with the highest prevalence currently among five- to twelve-year-olds and the lowest among people aged 65 and over.
- In February and March the number of trips abroad was on average “very, very low” compared to the previous months.
- When comparing infections and deaths and hospital admissions, the researchers observed “fewer deaths per infection” than they would have expected based on the last few months of the study.
Steven Riley, Professor of Infectious Disease Dynamics at Imperial College London, said, “The good news is that the prevalence is down about 60% from the February preliminary round to the current March results.
“The latest data shows no sustained apparent decline, we have a flattening in prevalence and this is reflected in an R-estimate of 1.
“And we’ve been seeing some differences between our observed infection patterns and death patterns since January, which we think likely suggests that mass vaccination disrupts that link between infections and deaths to some extent.”
Commenting on the infection, death and hospital admissions data, he said, “We are seeing fewer deaths per infection than we expected based on the last few months of the study.”
He added: “To a lesser extent, we are also seeing fewer hospitalizations per infection.
“We believe this is a signal of how the vaccination program is breaking the link between the pattern of infection and the pattern of deaths and hospitalizations.”
Prof. Riley warned that if the vaccine adoption rate was slowed down, researchers would expect higher rates of infection.
Professor Paul Elliott, Director of the School of Public Health Program at Imperial, said, “I think we are starting to see the effects of the vaccine in our data, certainly in serious consequences.”
He added that more work was needed to examine the impact of the vaccine on prevalence and transmission.
Prof. Elliott admitted that the “sharp drop” in the infection rate “flattened out” in March, but said it was “good news” that it came with the recent easing of restrictions, such as more permissible social mixing and return , has not increased from students to schools.
He said “close observation” is needed as the lockdown continues to be relaxed and a “careful balancing act” is required.