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, a South Korea study found.
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, the Korea Disease Control and Prevention Agency (KDCA) said on Tuesday.
The higher load means the virus spreads far more easily from person to person, increasing infections and hospitalizations, a health ministry official Lee Sang-won told a news conference.
“But it doesn’t mean Delta is 300 times more infectious … we think its transmission rate is 1.6 times the Alpha variant, and about two times the original version of the virus,” Lee said.
The Delta variant of the novel coronavirus was first identified in India and the Alpha variant in the U.K.