New modelling estimates the potential impact of the new COVID-19 strain

In December, the UK Government confirmed the identification of a new variant of SARS-CoV-2 in England, called VOC 202012/01, which was the cause of around a quarter of cases in London in November. While mutations are a common occurrence in virus evolution, research has shown that this strain has an increased ability to transmit than other variants - and therefore increase the reproduction (R) number.
Illustration of COVID-19. Credit: CDC/Alissa Eckert

In response to this development, research from LSHTM's Centre for Mathematical Modelling of Infectious Diseases (CMMID) analysed the potential impact of this new strain on the UK, and what measures would be needed to reduce the R number to below 1. Dr Nicholas Davies, Assistant Professor of Mathematical Modelling, explains the findings:

"The novel SARS-CoV-2 variant VOC 202012/01 appears to have spread rapidly in the south east of England, prompting a new set of Tier 4 restrictions from the UK government. A new preprint from the London School of Hygiene and Tropical Medicine assesses the transmissibility of this new variant and whether it has a higher likelihood of leading to hospitalisation or death compared to existing variants.

"Based on early data, the preprint finds that VOC 202012/01 may be 50-74% more transmissible than pre-existing variants of SARS-CoV-2. Although the researchers could not find any evidence from the data so far that there is any increase in the risk of hospitalisation or death for individuals who contract this new variant, the substantial increase in transmissibility means that recent increases in infection in the South East, London, and East of England may continue and spread to all regions of the UK unless rapid action is taken to control transmission. The researchers examine potential efficacy of interventions including Tier 4 with and without schools closed for January 2021 and how the UK’s vaccine rollout may reduce the potential burden of this new variant.

"From the scenarios they assessed, they conclude that a substantially increased vaccine roll-out and school closures for January 2021 may be needed to prevent COVID-19 deaths and hospitalisations in 2021 from exceeding those in 2020. The estimate of 50–74% increase in transmission is consistent with an estimate from another research group of 50-70% which was widely quoted in the media over the weekend. However, the researchers stress that given the urgency of the situation they were not able to assess all possible control options, and that more data will clarify the picture in the coming weeks and help to indicate the potential impact of control measures (including school closures) and for how long these may be needed."

***This research is a pre-print and has not yet been peer-reviewed***


Nicholas Davies, Rosanna C BarnardChristopher I JarvisAdam J KucharskiJames D MundayCarl A.B. PearsonTimothy W RussellDamien C Tully, Sam Abbott, Amy Gimma, William Waites, Kerry LM WongKevin van ZandvoortCMMID COVID-19 working group, Rosalind M EggoSebastian FunkMark JitKatherine E Atkins & W John EdmundsEstimated transmissibility and severity of novel SARS-CoV-2 Variant of Concern 202012/01 in England. Pre-print.

COVID-19 Response Fund

There cannot be any complacency as to the need for global action.

With your help, we can plug critical gaps in the understanding of COVID-19. This will support global response efforts and help to save lives around the world.