At least four million people have died worldwide since the Covid-19 pandemic began in late 2019.
A number of more infectious strands of Covid-19 have already emerged including the Alpha and Delta variants, which were first detected in Kent and India respectively.
The UK is currently battling a surge in coronavirus cases linked in part to the Delta variant.
Dr Perry Wilson, a Yale university epidemiologist, warned the Delta variant is spreading much faster than either Alpha or the original coronavirus.
Speaking to Yale Medicine he said: “It’s actually quite dramatic how the growth rate will change.
“In a completely unmitigated environment—where no one is vaccinated or wearing masks—it’s estimated that the average person infected with the original coronavirus strain will infect 2.5 other people.
“In the same environment, Delta would spread from one person to maybe 3.5 or 4 other people.
“Because of the maths, it grows exponentially and more quickly.
“Delta is outcompeting everything else and becoming the dominant strain.”
According to Inci Yildirim, a Yale infectious disease specialist, Delta is likely to impact the young more than previous variants.
She commented: “As older age groups get vaccinated, those who are younger and unvaccinated will be at higher risk of getting COVID-19 with any variant.
“But Delta seems to be impacting younger age groups more than previous variants.”
She added: “All viruses evolve over time and undergo changes as they spread and replicate.”
The WHO is also urging more cooperation from China into the origins of the coronavirus.
More to follow…