A total of 62 cases of Influenza A “subclade” K, also known as Superflu, have been identified in Indonesia, with the highest numbers reported in East Java, South Kalimantan, and West Java.
Based on whole genome sequencing (WGS) examinations, cases of Influenza A “subclade” K have been detected since August 2025, with 62 cases recorded as of December 2025.
Although this virus does not appear more severe, it still warrants close attention. According to the latest reports, one patient has died at Hasan Sadikin Hospital (RSHS) in Bandung after contracting Superflu.
Responding to the situation, Professor Tri Wibawa, a Microbiology lecturer at the Faculty of Medicine, Public Health, and Nursing at Universitas Gadjah Mada (FK-KMK UGM), stated that Influenza A “subclade” K is genetically different from previously circulating viruses.
Nevertheless, he confirmed that this subclade remains closely related to the seasonal influenza viruses that many people experience.
Virologists currently see no indication of unusual patterns in the virus’s evolution, as influenza viruses continuously change as part of their natural evolutionary process.
“So far, there is no evidence from laboratory or population studies that this variant can evade human immunity formed by previous influenza infections or vaccination,” he explained on Friday (Jan. 9).
According to Professor Wibawa, the term “superflu” used for this virus variant is not a scientific designation. Based on existing evidence, there are no indications that Influenza A “subclade” K is more virulent than the H3N2 influenza virus that has been circulating to date.
However, vigilance remains essential.
“We must remain alert, because the H3N2 influenza virus can indeed be fatal for vulnerable individuals, such as the elderly,” he explained.
Furthermore, Professor Wibawa noted that the Influenza A “subclade” K variant continues to evolve due to its genetic material (RNA). These minor genetic changes can give rise to new, closely related virus variants.
According to him, rapid viral changes and the emergence of significantly different variants can affect the human immune system.
“There is potential for the immune system to become unable to fight the virus, with other consequences such as faster transmission,” he said.
Professor Wibawa emphasized that preventing transmission of this virus variant can be achieved by practicing proper cough etiquette, wearing masks for those experiencing flu symptoms, washing hands regularly, getting adequate rest, and ensuring sufficient ventilation in indoor spaces.
He also stressed that vaccination should continue for vulnerable groups.
“Vaccination is still recommended for vulnerable groups, such as children, older adults, pregnant women, and people with chronic illnesses,” he concluded.
Author: Salwa
Editor: Gusti Grehenson
Post-editor: Rajendra Arya
Illustration: Freepik