London, March 4
The coronavirus variant that was first reported in the UK is more transmissible than pre-existing variants, and can lead to large resurgence of COVID-19 cases, according to a new modelling study.
The research, published in the journal Science, noted that without stringent control measures such as limited closure of educational institutions and a greatly accelerated vaccine roll-out, COVID-19 hospitalisations and deaths across England in 2021 will exceed those in 2020.
Reserachers, including those from London School of Hygiene and Tropical Medicine, estimate that the novel variant has a 43-90 per cent higher reproduction number than pre-existing variants of SARS-CoV-2 in England.
Reproduction number indicates the average number of people who will contract a contagious disease from one infected person.
After emerging in November last year, evidence began to emerge in December that VOC 202012/01 was rapidly outcompeting pre-existing variants in southeast England, the researchers said.
They noted that as of February 15, the variant comprises roughly 95 per cent of new SARS-CoV-2 infections in the UK, and has now been identified in at least 82 countries, including India.
Estimates of its growth rate, disease severity, and impact are crucial for informing policy responses, according to the researchers.
After analysing 150,000 sequenced SARS-CoV-2 samples from across the UK, they found that the relative population growth rate of VOC 202012/01 in the first 31 days following its initial observation was higher than that of all 307 other virus variant lineages.
To understand possible biological mechanisms for this, the researchers used an age- and regionally structured mathematical model of SARS-CoV-2 transmission to test several assumptions, including that the variant has a higher viral load or longer shedding period.
They identified increased transmissibility as the model that best explains the variant’s rapid spread.
The team used modelling to further analyse how interventions could reduce the potential burden of this new variant in the UK.
The researchers concluded that a substantially increased vaccine roll-out and school closures for 2021 may be needed to prevent COVID-19 deaths and hospitalisations in 2021 from exceeding those in 2020 in the UK.
They noted some limitations to their analysis, including having only considered a small number of intervention and vaccination scenarios. PTI