People infected with the more transmissible Delta variant have a viral load 300 times higher than those with the original version of the Covid-19 virus, when symptoms are first observed, according to a South Korea study.

But the amount gradually decreased over time — to 30 times in four days and over 10 times in nine days — and it matched levels seen in other variants after 10 days, Reuters cited the Korea Disease Control and Prevention Agency (KDCA) as saying.

The Delta variant of the novel coronavirus was first identified in India and the Alpha variant in the UK.