Updated on: 28 Jul 2026
CHENNAI: Tamil Nadu has detected the Omicron RF.5 sub-lineage in all 20 Covid-19 positive samples sent for genome sequencing between January and May this year. The State Health Department has, however, said the variant is mild and does not pose any immediate public health concern.
The samples were analysed at the National Institute of Virology (NIV), Pune, where all 20 were confirmed to be the RF.5 variant, Director of Public Health and Preventive Medicine Dr. A. Somasundaram said.
“All the 20 samples tested at NIV, Pune, have turned out to be RF.5. It is not a virulent virus, so people do not have to panic,” he said, while urging the public to continue following basic preventive measures.
Tamil Nadu currently has 15 active Covid-19 cases and has reported 335 infections so far in 2026. Health officials said the cases were identified through routine surveillance, with most patients experiencing only mild symptoms.
According to the Health Department, genome sequencing data indicate that the RF.5 strain causes mild illness and is circulating at relatively low levels in the community.
Dr. Somasundaram said surveillance is continuing under the Integrated Disease Surveillance Programme, while Covid-19 testing is currently limited to high-risk individuals, pre-operative patients and those with refractory acute respiratory illness.
He advised people experiencing fever, cough, sore throat or breathing difficulty to seek medical attention at the nearest government hospital. He also urged the public to wash their hands regularly and wear masks in crowded places if they are unwell.
The department has advised senior citizens, pregnant women and people with kidney disease, cancer or weakened immunity to avoid large gatherings as a precaution.
Health authorities noted that the RF.5 sub-lineage has also been reported in Andhra Pradesh, Singapore and several Southeast Asian countries, but there is no evidence that it causes more severe illness than other circulating variants.
