LONDON (AP) — Long lines have formed for booster shots across England as the U.K. government urged all adults to protect themselves against the omicron variant.

The British government also reported the country's first death involving the omicron variant.

Prime Minister Boris Johnson said everyone 18 and up would be offered a third vaccine dose by Dec. 31 to help withstand a coronavirus "tidal wave" driven by the variant.

That's a full month earlier than the previous target.

The health ministers say omicron is likely to replace delta as the dominant strain in London "in 48 hours."

Health authorities around the world are watching Britain see what an omicron surge looks like in a country with an older, more highly vaccinated population than South Africa's.

On Sunday, the UK raised the country’s coronavirus threat level after it was reported that 10 people were in British hospitals with omicron-related COVID-19, the Associated Press reported.

More information about the person who died was not immediately released.