NEW YORK - The World Health Organisation (WHO) on Wednesday flagged a new Covid-19 variant that is spreading quickly and widely.

Nicknamed “Eris” and officially designated EG.5, the new offshoot is rapidly gaining ground across the world. It is still of low concern, according to the WHO, and other factors may explain a current rise in hospitalisations in a number of countries, including the US. 

1. What is EG.5?

Eris is a descendant of a group of coronavirus strains labelled XBB. These are all offshoots of the Omicron variant, which arose in late 2021. EG.5 made up an estimated 17.4 per cent of global cases in the week ending July 23, according to the WHO, up from only 7.6 per cent four weeks earlier.

It is growing quickly in the United States, where it recently became the most common strain, according to estimates by the Centres for Disease Control and Prevention (CDC). 

2. How concerning is it?

Eris poses a low risk to global public health, the WHO said. Although it is growing in prevalence in comparison with other strains and appears to be better at evading the body’s immune defences, there is no evidence it causes more severe disease than other versions of the coronavirus.

The CDC has said there is no evidence it is able to spread more easily than its predecessors. Existing vaccines and treatments are expected to remain effective against it. Since it is closely related to the XBB family, that includes updated booster shots targeting those strains that will soon be available. 

3. What symptoms does it cause? 

The symptoms seem to be the same as those caused by other strains, said Dr Thomas Russo, chief of the Division of Infectious Diseases at the University of Buffalo’s medical school, in an e-mail. Common ones include a runny nose, headache, fatigue, a sore throat and sneezing.

People who are older, have compromised immune systems or suffer from multiple other conditions are at higher risk for more severe effects. These may include lower respiratory disease, chest pain and shortness of breath. The virus still kills hundreds of people each week in the US, so it is important for people to get tested if they think they may be infected.

4. What’s causing a rise in U.S. hospitalisations?

The number of people admitted to the hospital with Covid-19 is on the rise for the first time this year in the US, and wastewater data has also shown cases ticking up.

There is no evidence linking rising hospitalisations in multiple countries to new strains, the WHO said, and experts have pointed to other likely culprits.

Extreme heat is driving gatherings indoors, where the coronavirus spreads more easily. Also, with the pandemic over, people are travelling again and no longer wearing masks. And for many people, it has been months since they last got a vaccine or contracted the virus, meaning their immunity against infection is waning. 

5. Is the U.S. prepared for a rise in Covid-19?

The US has scaled back its response to Covid-19 in recent months. The government no longer buys vaccines and treatments for the public, and free tests are not as widely available. Still, experts say the country is not likely to see the kind of surge in cases that upended life in the early years of the pandemic.

Because of vaccination and prior infections, the American population has widespread protection from severe disease, and therapies like Pfizer’s Paxlovid antiviral drug can reduce the risk of hospitalisation and death if they are taken early on. Even after recent increases, hospital admissions are lower than at any other point since at least August 2020, according to CDC data.

6. What can people do to protect themselves?

New booster vaccines will be available in autumn, and experts say they are especially important for vulnerable people. If you are at higher risk, and are going to be in a situation where exposure is likely, such as a large gathering, Dr Russo said you can consider getting a booster shot of one of the older vaccines that are already on the market.

In any case, masks help protect against infection.

Pharmacies still sell at-home tests. If you are at high risk, and you develop symptoms, a test can help determine whether you should start taking Paxlovid. BLOOMBERG