Most of the infections during the second wave of COVID-19 in the State were due to the Delta variant, a study has shown.
Breakthrough infections, or infections that occur even after vaccination, were also due to the variant.
A preliminary report on the findings of the samples collected from those infected with COVID-19 revealed that the Delta variant (B 1.617.2) was the most common virus circulating in the State. The second most common was the Alpha variant (1.1.7).
The Directorate of Public Health (DPH) on Sunday released details of a study of whole genome sequencing of the virus it had carried out.
According to the DPH, 1,159 samples were collected from district surveillance units and sentinel sites from December 2020 to May 2021 and brought to the State Public Health Laboratory in the city for preliminary screening, followed by referral to InSTEM, Bengaluru.
The samples were classified under eight categories, including community clusters, family clusters, reinfection cases, vaccination breakthrough cases, children up to 12 years of age, young adults with severe lung involvement, deceased without any co-morbidities, and international travellers.
As of date, the results of 554 samples have been received, and those of 605 samples are awaited, according to Public Health Director T.S. Selvavinayagam. The Delta variant was observed in 386 (70%) out of 554 samples, and 47 samples (8.5%) had the Alpha variant (B.1.1.7).
The Delta variant was found predominantly among adolescents (aged over 12) and adults, accounting for 81%, while 19% of children also had the variant.
The Delta variant was noticed in community clusters (30%) and family clusters (23%). Of the 554 samples, 94 were from children aged up to 12, and among them, 73 (76%) had the Delta variant. There were as many as 66 vaccine breakthrough cases, of whom 55 exhibited the Delta variant, Dr. Selvavinayagam said.
