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, prompting the State Health Department to reiterate that the circulating strain is mild and poses no immediate public health concern.
The samples, analysed at the National Institute of Virology (NIV), Pune, confirmed the presence of 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. The State has recorded 335 infections so far in 2026. Health authorities said the cases were detected through routine surveillance and that the overwhelming majority of patients had only mild symptoms.
According to the health department, genome sequencing findings from NIV indicate that the strain now in circulation causes mild illness and is spreading at relatively low levels within communities.
Somasundaram said the State continues to maintain surveillance under the Integrated Disease Surveillance Programme, while Covid-19 testing is presently 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 visit the nearest government hospital without delay. “People should wash their hands regularly and wear a mask in crowded places if they are unwell,” he said.
The department has also advised senior citizens, pregnant women and those with kidney disease, cancer or weakened immunity to avoid large gatherings. The RF.5 sub-lineage has also been reported from Andhra Pradesh, Singapore and several parts of Southeast Asia, but health authorities maintain there is no evidence of increased severity associated with the variant.