Want to know when COVID-19 is most transmissible? Find out

Amid the world preparing for the third wave of the COVID-19, people are always looking to find out how contagious coronavirus actually is. According to a new study conducted by Boston University researchers, individuals infected with the virus are most contagious two days before, and three days after they develop symptoms.

The study was published in the journal JAMA Internal Medicine which also found that individuals infected with COVID-19 were more likely to be asymptomatic if they contracted the virus from a primary case (the first infected person in an outbreak) who was also asymptomatic.

Leonardo Martinez, Assistant Professor of epidemiology at the varsity's School of Public Health, said, "Our results suggest that the timing of exposure relative to primary-case symptoms is important for transmission, and this understanding provides further evidence that rapid testing and quarantine after someone is feeling sick is a critical step to control the epidemic."

The team conducted contact tracing and studied COVID-19 transmission among approximately 9,000 close contacts of primary cases in the Zhejiang province of China from January 2020 to August 2020.

"Close" contacts included household contacts (defined as individuals who lived in the same household or who dined together), co-workers, people in hospital settings, and riders in shared vehicles. 

In comparison to mild and moderate symptomatic individuals, asymptomatic primary individuals were much less likely to transmit COVID to close contacts -- but if they did, the contacts were also less likely to experience noticeable symptoms.

"This study further emphasises the need for vaccination, which reduces clinical severity among people that develop COVID," Martinez said.

(With inputs from IANS)