The UK severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, also known as the B.1.1.7 variant, has been spreading since October 2020. Since then, it has reached many countries worldwide.
The UK variant is confirmed to be transmissible than earlier strains, and recent studies revealed that it may even cause more severe illness.
Researchers at the University of Texas at Austin and Santa Fe Institute in the US used quantitative polymerase chain reaction (PCR) data from a surveillance testing program on a large university campus to estimate how fast the new variant spreads. The team used the data to provide local situational information on the COVID-19 pandemic.
The study, published on the medRxiv* server, showed that the estimated proportion of SARS-CoV-2 infections caused by the B.1.1.7 variant at the University of Texas increased community infections by 17.9 percent in February 12. By March 5, the UK variant is thus expected to comprise a majority of the cases.
The B.1.1.7 variant
Though the B.1.1.7 variant has started spreading in October 2020, it was not until December 2020 that concern was raised among public health officials about a surge of cases in southeastern England.
The variant accounted for about 5 to 10 percent of all coronavirus disease 2019 (COVID-19) cases in the UK. It was initially designated as Variant Under Investigation (VUI)-202012/01 but was later named Variant of Concern (VOC-202012/01) or B.1.1.7.
Since then, the new variant has been reported in many countries globally, including the US. Alongside this variant, the South African variant, called B.1.351, has also emerged.
The B.1.1.7 variant has a mutation on the receptor-binding domain (RBD) of the virus’s spike protein at position 501, where the amino acid asparagine (N) has been replaced with tyrosine (Y). This mutation is called N501Y.
To arrive at the study findings, the team estimated the prevalence of the UK variant based on daily positive SARS-CoV-2 PCR tests and the number of S gene target failures (SGTF) out of 17,003 student tests from January 16 to February 12, 2021.
The team found that the relative frequency of B.1.1.7 is growing at a daily rate of 0.077, which links to an early doubling time of 9 days. The estimates were parallel with the growth rates estimated in the UK, Florida, and California.
In the University of Texas community, the estimated proportion of SARS-CoV-2 infections caused by the U.K. variant increased from 2.7 percent on January 16 to 17.9 percent by February 12.
Meanwhile, the team projected that the B.1.1.7 variant would cause most university cases by March 5. Also, assuming that the B.1.1.7 variant is 1.56 times as transmissible as the wildtype variant, the team projects that its emergence will lead to a 77 percent increase in infections during the spring semester.
The team added that while the estimates were derived from limited surveillance data, they are consistent with the trends seen in the UK and the US. The researchers urged for expanded molecular surveillance capacity and continuous COVID-19 mitigation efforts, such as social distancing, regular hand hygiene, and masks wearing in public places.
To date, there have been over 117.53 million cases worldwide, with over 2.6 million COVID-19-related deaths. The US remains to have the highest number of cases, reaching 29 million with over 527,000 deaths.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.