A new strain of Covid-19 which has been predicted to become the dominant variant globally in the next few months, is rapidly spreading through Europe and the United States.

The new variant, known as XEC, was first detected in Germany in June but has spread across 27 countries, including France and the US, infecting more than 600 people.

XEC is the latest in a long list of past and current Covid variants being monitored as the Covid-19 virus naturally evolves.

The strain has been described by health experts as a recombinant variant. Recombinants can occur naturally when a person is simultaneously infected with two different Covid-19.

The XEC variants, health experts say, is a product of recombination between two hybrids of previously discovered omicron sub-variants – KS.1.1 and KP.3.3. These two parent variants are closely related, having both evolved from JN.1, which was the dominant variant around the world at the start of 2024.

Researchers detect XEC cases through the Gisaid public database, where viral genetic sequences are submitted for examination. This platform enables the identification of mutations in SARS-CoV-2, the virus responsible for Covid-19.

Currently, the US has reported 118 XEC cases, the highest globally. Germany has 92 XEC cases, the UK has 82, Canada has 77, and Denmark has 61 cases according to media reports but actual figures are likely to be higher in nations that do not regularly sequence Covid samples.

Mutation

In Europe and North America, the dominant variant is KP.3.1.1, while Asia is primarily affected by the closely related KP.3.3 variant.

XEC has not been reported from any African country, but experts suggest that the strain is likely to become the dominant variant globally in the next few months.

Compared to other strains, XEC is said to have a higher growth advantage, spreading much more rapidly than the others.

Experts said XEC has this advantage because of its relatively rare T22N mutation (inherited from KS.1.1) combined with Q493E (from KP.3.3) in the spike protein.

The spike protein is said to play a crucial role in helping the virus attach to human cells, allowing it to enter and begin replication.

However, the impact of the T22N mutation on the virus’ ability to replicate or spread among individuals remains largely unclear.

The first strain of Covid-19 and the first known case of the virus emerged in December 2019, with initial cases reported in the city of Wuhan, Hubei province, China.

The virus, later identified as SARS-CoV-2, rapidly spread worldwide, leading to the pandemic declaration by the World Health Organization (WHO) in March 2020. In Nigeria alone, at least 267,000 Covid-19 cases were recorded with a case fatality rate of 1.2 per cent.

How XEC spreads

Since the initial outbreak of Covid-19, several new strains, or variants, of the SARS-CoV-2 virus have emerged due to mutations.

These variants reflect the ongoing evolution of SARS-CoV-2, with some causing more severe waves of infection than others, often influenced by their ability to spread and evade immunity.

The newest coronavirus variant, XEC, spreads mainly via respiratory droplets released into the air when an infected individual breathes, talks, coughs, or sneezes. Though the virus can persist on surfaces, surface transmission is said to be less frequent compared to airborne spread.

As a result, health authorities recommend maintaining social distancing, wearing masks in public settings, and regularly using hand sanitiser to minimise the risk of infection.

The XEC variant does not have any unique symptoms. Like other variants, XEC can lead to symptoms like sore throat, fever, fatigue, and muscle aches, which typically emerge within two to 14 days after exposure.

These symptoms are often mild, but the severity can range widely. High-risk individuals, including the elderly, may experience more intense illness, while some cases may show no symptoms at all.

PT