Delta variant’s higher infectivity helps its quick spread
July 26, 2021
KARACHI: Since first appearing in India in late 2020, the Delta variant of SARS-CoV-2 has become the predominant strain in much of the world. Researchers might now know why Delta has been so successful: people infected with it produce far more virus than do those infected with the original version of SARS-CoV-2, making it very easy to spread, mentions Sara Reardon while reporting for Nature magazine published on July 23, 2021.
According to current estimates, the Delta variant could be more than twice as transmissible as the original strain of SARS-CoV-2. To find out why, epidemiologist Jing Lu at the Guangdong Provincial Center for Disease Control and Prevention in Guangzhou, China, and his colleagues tracked 62 quarantined people exposed to Covid-19 and who were some of the first people in mainland China to become infected with the new deadly strain. The team tested study participants’ ‘viral load’ - a measure of the density of viral particles in the body - daily throughout the course of infection to see how it changed over time. Researchers then compared participants’ infection patterns with those of 63 people who contracted the original SARS-CoV-2 strain in 2020.