Highly transmissible but mild Covid strain now dominant

Virologist expects JN.1 cases to soar for a few weeks before dropping again

The JN.1 strain of Covid-19, which is highly transmissible but with mild symptoms, is now dominant in the country, says the well-known virologist Yong Poovorawan.

The strain was first detected in the United States and is expected to replace all other strains of Covid-19 because it spreads so easily, he wrote on Facebook on Thursday.

“Those infected with the JN.1 strain will not have severe symptoms. Some people only have a cold and sore throat, like ordinary respiratory illnesses,” said Prof Yong, head of the Centre of Excellence in Clinical Virology at Chulalongkorn University. 

“It is highly transmissible and repeated infection is possible. So, cases will soar, especially after New Year. Their number will start to drop in February and plunge in March.”

Later infections will subside until the next spread season starts in June, he wrote.

Dr Thongchai Keeratihattayakorn, director-general of the Department of Disease Control, said Covid-19 still needs to be monitored closely because it mutates continuously.

Although most people have immunity and their symptoms are mild, vulnerable people should take precautions, especially elderly people, pregnant women and those with hypertension, chronic kidney failure, obesity and cancer, he warned.

Last year there were 652,868 Covid-19 cases, with 848 deaths linked to the disease. Dr Thongchai expects there will be 649,520 Covid-19 cases this year.