The JN.1 covid variant spread rapidly in December 2023 and has now become the most common strain of the virus circulating in the US, according to the US Centers for Disease Control and Prevention (CDC), increasing the total number of new cases and to a lesser extent hospital admissions.

JN.1 cases are also increasing in the United Kingdom and France, China and India, and other European countries, as well as in our country.

The professor of Epidemiology and Preventive Medicine at the Faculty of Medicine of the EKPA Theodora Psaltopoulouthe biologist Panagiota Zacharakis and the doctor John Danasis summarize the latest data.

International health authorities point out that it is not yet certain whether JN.1 infections cause different symptoms than other variants, with the CDC noting that “the types of symptoms and how severe they are usually depend more on immunity and general health of an individual rather than from which variant it causes the infection’.

The symptoms

According to the CDC, symptoms of this subtype include: Cough, sore throat, headache, muscle pains, fever, loss of taste and smell, runny or stuffy nose, fatigue, brain fog, shortness of breath and mild gastrointestinal symptoms (stomach upset, slight diarrhea).

The latest data from the UK Office for National Statistics, from December 2023, suggests that the most commonly reported symptoms among respondents with covid-19 include: Runny nose (31.1%), cough (22.9%), headache (20.1%), weakness or fatigue (19.6%), muscle pain (15.8%), sore throat (13.2%), sleep problems (10.8%) , worry or anxiety (10.5%).

Many of the most common symptoms, including a runny nose and cough, have been reported in people with covid since 2020, although the list includes some new additions, such as sleep problems and anxiety. Additionally, loss of taste and smell – once considered a telltale sign of covid – is now only reported by 2 to 3 per cent of infected people in the UK.

The sudden rise in JN.1 suggests that it is either more contagious or better at evading our immune system (immune evasion). However, based on existing data, it does not appear to be more aggressive than other circulating variants, according to the CDC.

Finally, the recommendations, worldwide, for the prevention and treatment of covid-19 remain the same: Be careful indoors and if you are positive it is better to stay at home, isolated from others for a few days. According to the US Centers for Disease Control, “it is important to know that existing vaccines and treatments still work well against the JN.1 subvariant as well, so this subvariant does not affect CDC recommendations.”