Mutations of the Delta variant detected in Sri Lanka could develop into a new variant in the future, Sri Jayewardenepura University Department of Immunology and Molecular Biology Head Dr. Chandima Jeewandara warned yesterday.

“We have identified three mutations of the Delta variant spreading in Sri Lanka. In Colombo city, the Delta variant with all three mutations is dominant. Sri Lanka is the first country where the Delta variant with all three mutations has been reported,” Dr. Jeewandara said.

He explained that of the three mutations detected in Sri Lanka, the A701S mutation has only been reported from Sri Lanka, while the A1078S mutation has been only reported from Sri Lanka and Malaysia.

The rapid spread of the Delta variant is due to the A222V mutation, Dr. Jeewandara added.

The findings are a result of a study on 88 samples, of which 84 samples were of the Delta variant. The samples were collected from across the country, including Malabe, Maharagama, Vavuniya, Ratnapura, Gampaha, Matale, Kandy, and Nuwara Eliya.

On Twitter, Dr. Jeewandara yesterday explained that 74% of infections with the Delta variant took place during the presymptomatic phase. This was a higher proportion than previous variants, he said.

“Before Delta emerged, individuals infected with SARS-CoV-2 took an average of 6.3 days to develop symptoms and 5.5 days to test positive for viral RNA, leaving a narrower window of 0.8 days for oblivious viral shedding,” he tweeted.

According to Dr. Jeewandara, on average, people began having symptoms 5.8 days after infection with Delta. This is 1.8 days after they first tested positive. “That left almost two days for individuals to shed viral RNA before they showed any sign of COVID-19,” he tweeted.

However, Dr. Jeewandara added that vaccinated persons were 65% less likely than unvaccinated persons to infect someone else.

3,839 persons test positive for COVID-19, over 4,000 delayed cases added to total

213,737 persons vaccinated against COVID-19 on Thursday