The new, more contagious strain of Covid-19 that first emerged in the southeast of England was already spreading rapidly even during the nation’s second lockdown in November, according to a report published Thursday by scientists at Imperial College London.
A report by scientists at Imperial College London released on December 31 estimated that the new coronavirus strain tripled its number of infections in England during the November lockdown while the number of new cases caused by the previous variant decreased by a third.
The new strain registered a higher reproduction (R) rate – which determines how contagious a disease is based on the number of people infected by each infected person – of 0.7 versus 0.4 for the previous strain, even with the “high levels of social distancing” during the pre-Christmas lockdown.
An R rate must be less than 1 for the number of new cases to start falling. The British government’s latest estimate of the R rate for the UK as a whole, published on December 23, was between 1.1 and 1.3.
The emergence of the new Covid-19 strain prompted more than 50 countries to impose travel restrictions on the UK in late December, many of which were subsequently lifted. France reported its first case of the new variant on its soil on December 25.
“There is a huge difference in how easily the variant virus spreads,” Axel Gandy, a statistician at Imperial College London and a co-author of the report, told the BBC. “This is the most serious change in the virus since the epidemic began,” he said.
The Imperial College research also found the new strain was initially spreading most rapidly among people under 20 years of age but it then started spreading to other age groups.
“The early data was collected during the time of the November lockdown where schools were open and the activities of the adult population were more restricted,” Gandy said. “We are seeing now that the new virus has increased infectiousness across all age groups,” he continued.
The government reimposed lockdown measures on areas covering 78 percent of the English population on Wednesday while regional authorities in Scotland, Wales and Northern Ireland have also brought back confinement measures.
Intensive care units in London and the surrounding southeast region exceeded their capacity on December 29, with occupancy reaching 114 and 113 percent respectively, according to NHS data leaked to specialist publication the Health Services Journal. In response, the government activated one of its Nightingale Hospitals – designed to deal exclusively with Covid-19 patients, thereby taking the pressure off overburdened hospitals – in London on December 31.
The Imperial College report suggested that keeping schools closed after the Christmas holidays will help contain the virus’s spread: “A particular concern is whether it will be possible to maintain control over transmission while allowing schools to reopen in January.” The government has extended the Christmas holidays until January 11, when secondary schools in England are scheduled to resume classroom attendance. Pupils will return to English primary schools on January 4, except in the most severe virus hotspots including London.
It is “inevitable” that schools will have to stay closed to stop the new Covid-19 variant running out of control, Deepti Gurdasani, a clinical epidemiologist and a senior lecturer at Queen Mary, University of London, told the Financial Times.
The number of deaths from Covid-19 reached 981 on Wednesday, the highest daily toll since the coronavirus first surged in the spring. Overall, the UK has seen more than 2.5 million confirmed coronavirus cases, while its death toll stands at more than 74,000, the second-highest in Europe after that of Italy and the sixth highest in the world.
The government will have to accelerate the rollout of vaccines if it wishes to contain the new Covid-19 strain, its scientific advisory committee suggested on December 22, warning that “current rates of vaccination are unlikely to significantly change the epidemiology” of the virus.
The UK was the first Western country to approve both the Pfizer-BioNTech and Oxford-AstraZeneca jabs for emergency use. Authorities have so far distributed one million vaccines, Health Secretary Matt Hancock wrote in a tweet. More than 940,000 people have had the first jab, the BBC reported.