Juan Gaertner / Source of Science
After months of data collection, researchers agree: The Delta variant is the most contagious version of coronavirus worldwide. It spreads approx. 225% faster than the original version of the virus, and it currently dominates the outbreak in the United States.
A new study published online on Wednesday sheds light on why. It finds that the variant is growing faster in people’s respiratory tract and to much higher levels, researchers at Guangdong Provincial Center for Disease Control and Prevention report.
On average, people infected with the delta variant had approximately 1,000 times more copies of the virus in their airways than people infected with the original strain of coronavirus, the study reports.
Additionally, after someone catches the delta variant, the person is likely to become contagious faster. On average, it took only about four days for the delta variant to reach detectable levels inside a person compared to six days for the original coronavirus variant.
In the study, researchers analyzed COVID-19 patients involved in the first outbreak of the delta variant in mainland China, which occurred between May 21 and June 18 in Guangzhou, the capital of Guangdong province. The researchers measured the virus levels in 62 people involved in this outbreak and compared them with the levels in 63 patients who became infected back in 2020 with an early version of the virus.
Their findings suggest that people who have been given the delta variant are likely to spread the virus earlier in the course of their infection.
And the researchers stress the importance of quarantine immediately for 14 days after being in contact with someone diagnosed with COVID-19, as recommended by the US Centers for Disease Control and Prevention.
Or even better, to be fully vaccinated. Preliminary data show that in some U.S. states, 99.5% of COVID-19 deaths in the last few months were among people who were not vaccinated, said CDC Director, Dr. Rochelle Walensky, Thursday at the White House.
“We know that the delta variant … is currently rising in the country’s pockets with low vaccination rates,” she said. “We also know that our approved vaccines prevent serious illness, hospitalization and death from the delta variant.”