What are the symptoms of the Omicron Covid variant?

Virus strain is highly infectious but is thought to be less severe than other variants

A locked gate blocks access to a bar area in Berlin. Germany's government has put a lid on New Year celebrations, with nightclubs slated to close from December 28 onwards. AFP

A jogger runs past the Covid-19 Memorial Wall in London. EPA

People receive the Moderna booster at a vaccination centre in Antwerp, Belgium. Many are flocking to receive their booster shots amid surging Omicron infections. AP

People wearing face masks pose for a photo outside a coffee shop with Christmas-themed decorations in Athens, Greece. AP

A woman tapes the word "Omicron" to a handmade effigy depicting the Omicron coronavirus variant in Managua. The effigies will be burnt at midnight on December 31 as a tradition of saying goodbye to the old year and welcoming the new. AFP

Delivery workers of South Korea's leading logistics company CJ Logistics Corporation protest in the capital Seoul over working conditions. EPA

Shoppers hunt for bargains in Tokyo as people prepare for the New Year celebrations. Authorities in Tokyo, Osaka and Kyoto have announced free PCR tests to reduce infection risk especially during the holidays in Japan. EPA

Travellers at the international airport in Samut Prakan, Thailand. Authorities have suspended quarantine-free entry to the country for all passengers, to contain the spread of the Omicron variant. EPA

People queue for Covid-19 status checks before entering the Egyptian Museum, in Turin, northern Italy. EPA

A woman takes a Covid-19 test at a pop-up testing site as the Omicron coronavirus variant continues to spread in Manhattan, New York. Reuters

Workers check the body temperatures of pupils arriving for Year 12 examinations at a school in Phnom Penh, Cambodia. EPA

Thousands of people on Copacabana Beach in Rio de Janeiro, Brazil, on December 26. Brazil's beaches are crowded with the arrival of summer despite the worldwide spread of the Omicron Covid-19 variant. Authorities will hold a New Year's Eve party on the Copacabana shore. Getty Images

People gather during a demonstration of the cultural sector against the closure of venues under new rules put into place against Covid-19, in Brussels, Belgium. EPA

Shoppers during Boxing Day sales in Glasgow. New restrictions have been introduced in Scotland, Northern Ireland and Wales. Getty Images

A woman takes a Covid-19 test in Times Square as the Omicron coronavirus variant continues to spread in New York City. Reuters

Hospital workers gather for a selfie in the Covid-19 intensive care unit of the La Timone hospital in Marseille, southern France. One of the country’s largest hospitals, La Timone has weathered wave after wave of coronavirus. AP

Cricket fans arrive on the first day of the third Ashes Test between Australia and England in Melbourne, Australia. EPA

A screen at the San Francisco International Airport shows cancelled United Airlines flights to Chicago O'Hare and Cleveland on Christmas Eve. EPA

Travellers wait for trains on the eve of Christmas, at Euston Station in London. EPA

Pastries named "virus" and "vaccine" on display in the window of a cafe and pastry shop in Prague, Czech Republic. Countries in central Europe are preparing for what many fear will be a fifth wave of the coronavirus brought on by the rapid spread of the Omicron variant. Getty Images

People wait to receive vaccine doses at a shopping centre in Sarajevo, Bosnia and Herzegovina. EPA

People rush to receive Covid-19 testing kits from city workers in the Brooklyn area of New York. The city is handing out thousands of the kits, which include two tests per box, as part of efforts to reduce the surge of people in long lines at testing sites. AFP

People queue on Christmas Day for booster shots in Rotterdam, the Netherlands. EPA

Newly elected President Gabriel Boric receives the third booster shot of the Pfizer vaccine in Santiago, Chile. Getty Images

Live updates: follow the latest news on Covid-19 variant Omicron

The Omicron variant of Covid-19 has spread rapidly throughout the world, leading many countries to reintroduce or tighten restrictions in an effort to slow its spread.

While initial evidence suggests Omicron may be less severe than previous Covid variants, it is believed to be more transmissible and more able to evade the protection offered by current vaccines.

What are the symptoms of the Omicron Covid variant?

In the UK, the National Health Service has said the main symptoms of Covid-19 are a high temperature, a new and continuous cough, and changes to people's sense of smell or taste.

But early signs suggest that there are other symptoms that may be more specific to the Omicron variant, including sneezing, fatigue, a headache, lower back pain, fever, scratchy throat, night sweats and a runny nose.

There are also signs that a changed sense of smell or taste is less likely to be a symptom, as has been the case previously.

How easy does Omicron spread?

Early research from experts in Hong Kong, based on lab testing of tissue samples, has shown Omicron replicates up to 70 times faster in the airways leading to the lungs than the Delta variant, which may help explain its rapid spread throughout the population.

But its apparent mildness may be explained by the same Hong Kong study that showed Omicron replicates 10 times slower in the lungs than Delta does.