Kerala, Andhra Pradesh and Chandigarh reported their first Omicron case on Sunday, while Maharashtra and Karnataka each recorded one more case of the COVID-19 variant, taking the tally in the country to 38. All the five persons in the cases reported on Sunday had arrived from foreign countries. The Omicron variant was first detected in India in Bengaluru with two people testing positive for it comprising a South African national of Indian origin and a doctor. Cases of Omicron, which is categorised as a “variant of concern” by the World Health Organisation, have been detected in about 60 countries. The Omicron coronavirus variant is more transmissible than the Delta strain and reduces vaccine efficacy but causes less severe symptoms according to early data, the World Health Organization said Sunday. The Delta variant, first identified in India earlier this year, is responsible for most of the world's coronavirus infections. But South Africa's discovery of Omicron -- which has a large number of mutations -- last month prompted countries around the world to impose travel bans on southern African countries and reintroduce domestic restrictions to slow its spread.