It all started as a single genetic sample in a British database of many thousands.
Scientists from the UK’s COVID-19 Genomics UK Consortium (COG-UK) first detected coronavirus variant B.1.1.7 in September in the English county of Kent. It took almost three months before they discovered that the “Kent variant” was 70% more transmissible than the existing variants, and more weeks before another shocking discovery: it was also much more deadly.
The coronavirus has undergone thousands of mutations since its emergence in 2019, but most make no difference in its impact on human health. But B.1.1.7 – also known as VOC (“concern variant”) 202012/01 – spurred an increase in cases that flooded Britain’s hospitals, raised its death toll to over 125,000 and caused travel bans in dozens of countries.
The Kent variant has now gone global. In other parts of Europe, it fueled the third wave of the pandemic, which has created blockages and threatens to overcome slow vaccination programs. The Kent variant will be the dominant strain in the United States by the end of this month, say experts, who warn the country to prepare for the impact and not – as some states have – to loosen restrictions.
The rise of the United Kingdom variant in Britain
Weekly distribution of approximately 230,000 virus samples
A Reuters analysis of nearly 230,000 samples shows how B.1.1.7 increased dramatically to overtake the previously dominant “GV” strain.
Where it all began
The first case of B.1.1.7 was detected elsewhere in Kent, but the first variant took over Sheppey Island – a flat, swampy island in the River Thames estuary – and its Swale neighborhood. Sheppey had barely been touched by the first wave of the pandemic last spring, but in October the virus began to spread rapidly across the island. For most of November, England was under a second national blockade, but cases in Kent continued to increase. Only later did scientists realize that B.1.1.7 was so transmissible that it was overcoming restrictions.
The Medway Maritime Hospital in Gillingham, which serves Sheppey and the rest of the populous north of Kent, suffered the initial impact of B.1.1.7. In the first two weeks of November, the number of Covid patients in the hospital doubled. Medway Maritime would soon become Britain’s busiest Covid hospital, with almost half of its general beds and intensive care for adults occupied by patients with the disease.
From drip to torrent
The COVID-19 Genomics UK Consortium (COG-UK) tracks mutations in the coronavirus by sequencing or “reading” its complete set of genetic instructions or genomes. COG-UK sequences thousands of samples every week, allowing us to track how B.1.1.7 has spread across Britain.