JN.1: What is the Covid variant and which countries has it spread to?

The World Health Organization (WHO) has classified the JN.1 coronavirus strain as a "variant of interest".

WHO flagged its rapidly increasing spread, leading them to classify it as “a separate variant of interest (VOI) from the parent lineage BA.2.86” on Tuesday (December 19).

Centers for Disease Control and Prevention (CDC) recently flagged the re-emergence of the strain and said more needs to be learned about the variant, and that a close eye should be kept on it, especially as it said that "for as long as we have Covid-19, we’ll have new variants".

Which countries has the JN.1 variant spread to?

The new variant has been found to be spreading through countries including the US where it was initially spotted, the CDC has said. Other countries include the UK, Iceland, Portugal, Spain, and the Netherlands. An expert warned it has been "taking off" in France.

It was found that the countries reporting the largest proportion of JN.1 sequences between November 27 to December 3 are France (20.1 per cent, 1,552 sequences), the United States of America (14.2 per cent, 1,072 sequences), Singapore (12.4 per cent, 934 sequences), Canada (6.8 per cent, 512 sequences), the United Kingdom (5.6 per cent, 422 sequences), and Sweden (5.0 per cent, 381 sequences).

UK cases have been spotted as the UK Health Security Agency recently urged Brits to get Covid jabs following expectations flu and coronavirus infections will increase this winter.

A total of 11.7 million people in England have had the flu vaccine so far and 8.6 million have taken up the Covid-19 booster. However, millions more in vulnerable groups remain at risk, it has been thought.

What is JN.1?

JN.1 is a Covid variant that descended from BA.2.86 – the Pirola variant from Omicron. Dr Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security, has likened JN.1 to “another Omicron variant”.

JN.1 and BA.2.86 are very similar but differ in spike protein. The spike (which lays on the virus's surface) is what causes the virus to infect people. For this reason, the spike is what vaccines will target, but CDC predicts that vaccines will work in the same way to target both variants – just as updated vaccines were effective treatment for BA.2.86.

What are the symptoms of JN.1?

The other difference is that JN.1 is a derivative of BA.2.86, so there is some concern it may be more transmissible and reveal different symptoms. On ITV's This Morning, Dr Nighat Arif spoke of the change.

She said: “So with the new variant, the Pirola variant, we know that not only do you get temperature, runny nose, a headache, we still have that loss of sense of smell, but you might actually get diarrhoea with it. Stomach cramps can also appear with the Pirola strain."

Dr Arif added that extreme fatigue may also be a tell-tale sign as people have been feeling shattered after catching it.

Should we be worried in the run-up to Christmas?

As the festive period begins, many will remember the Covid spikes that have accompanied recent Christmases.

Although virus levels are decreasing, scientists are predicting this trend will reverse as we start to socialise more, with indoor gatherings.

The latest data shows Covid cases decreasing from a positivity rate of 6.6 per cent to 5.8 per cent of the population.

"We're going to see a fairly large rise in cases this winter," Professor Locker, a virologist at the Pirbright Institute, told Sky News. "Not because JN.1 is more problematic, infectious or severe, but because we're losing our defences – protections afforded by our last set of boosters and our immunity is waning."

Professor Bryant, professor of innate immunity at the University of Cambridge, said people have become "complacent" about Covid, despite "lots of people having it at the moment".

"There are lots of other germs around as well – flu is circulating, and other colds.

"If you have symptoms, you should test for Covid so you know how best to protect those around you."