A study published ‘Science’ points out that its contagion capacity is up to 90% greater and warns that it could cause important outbreaks.

A nurse giving the Pfizer vaccine to a patient.

The British variant of the coronavirus, whose scientific name is B.1.1.7, already accounts for 95% of new infections in the United Kingdom and has spread to at least 80 countries, according to a study published this Wednesday in the journal Science. The research, carried out by scientists from the London School of Hygiene and Tropical Medicine, once again warns about the contagion capacity of this strain, which is between 43% and 90% higher.

Scientific work not only delves into the greater propagation capacity of the British variant, but also underlines that, despite not causing a more serious disease, it could be linked to a 58% increased risk of death. “Without strict control measures, including limited closure of educational institutions and highly accelerated vaccine implementation, COVID-19 hospitalizations and deaths in England in 2021 will exceed those in 2020,” the study authors note.

After being detected in November 2020, scientists warned that this virus mutation was rapidly outpacing pre-existing variants in south-east England as early as December. As of February 15, 2021, it comprises approximately 95% of new infections. Estimates of its growth rate, severity and impact of the disease are crucial to inform policy responses.

After analyzing 150,000 sequenced SARS-CoV-2 samples from across the UK, Nicholas Davies and colleagues at the Center for Mathematical Modeling of Infectious Diseases (CMMID) found that the population growth rate relative to this variant in the first 31 days after its initial observation was higher than that of the other 307 variant lineage viruses.

To understand potential biological mechanisms for this, the authors used an age and regional structured mathematical model of SARS-CoV-2 transmission to test various assumptions, including that the variant has a higher viral load or a longer shedding period. Based on their analysis, they identify increased transmissibility as the model that best explains the rapid spread of the variant.

Davies and colleagues used modeling to further explore how interventions could reduce the potential burden of this new variant in the UK. From the scenarios they evaluated, they conclude that a substantial increase in vaccine implementation may be necessary and school closings by 2021 to prevent COVID-19 deaths and hospitalizations in 2021 from exceeding 2020.

The authors note limitations to their analysis, including that only a small number of intervention and vaccination scenarios were considered. Even so, they conclude, their projections point to “an urgent need to consider what new approaches may be necessary to sufficiently reduce the ongoing transmission of SARS-CoV-2.”