Genome sequencing of the samples of four COVID-19 infected lions at the Arignar Anna Zoological Park at Vandalur, near here, has revealed that they belong to Pangolin lineage B.1.617.2 and are Delta variants as per WHO nomenclature, the park said on Friday.

On May 11, this year, the World Health Organisation (WHO) classified B.1.617.2 lineage as a variant of concern (VOC), and said it showed evidence of higher transmissibility and reduced neutralization, the zoo's deputy director said.

AAZP sent samples of 11 lions housed in the park to test for SARS CoV-2 four lions on May 24 and seven on May 29 to the ICAR-National Institute of High Security Animal Diseases (NIHSAD), Bhopal.

In its communication on June 3, the institute said samples of 9 lions had tested positive for SARS CoV-2.

Thereafter the animals have been under active treatment.

The deputy director said in a statement that the Institute shared the results of genome sequencing of the SARS CoV-2 virus that infected the lions following a request from the zoo authorities.

"The director ICAR-NIHSAD informed that the Genome sequencing of four of the samples was done at NIHSAD, Bhopal. Analysis of the sequences shows that all the 4 sequences belong to Pangolin lineage B.1.617.2 and are Delta variants as per WHO nomenclature," the release stated.

A nine-year-old lioness Neela and a male lion named Pathbanathan, aged 12 years, succumbed to COVID-19 earlier this month.