(Bloomberg) --

The U.K. is poised to offer Covid booster shots to all adults and second shots to more children amid worries that the new omicron variant could spread even more easily and fuel another surge in cases.

A committee that advises the U.K. government said all adults should be eligible for a third dose, with availability expanded to those under 40. Children ages 12 to 15 should get second shots, the group said. 

An expansion of the booster program comes with tougher pandemic rules set to take effect this week in the U.K. Prime Minister Boris Johnson’s government is seeking to buy scientists time to determine the risks posed by the new strain. The announcement also follows a World Health Organization warning that the variant could fuel a new surge with “severe consequences.” 

The U.K. had previously made boosters available to those over 40. It’s largely using the vaccine from Pfizer Inc. and BioNTech SE, as well as shots from Moderna Inc., for the adult booster campaign, with teens offered Pfizer-BioNTech. Older teens have already been able to get second shots.

Booster doses should be given no sooner than three months after the primary course.

Scientists in South Africa, where omicron was first detected, said it appears to be more transmissible, but that existing vaccines are still likely to protect against severe illness. The WHO assessed the variant’s risk as “extremely high” and called on member states to test widely. Understanding the new strain will take several days or weeks, the agency said. 

Governments are banning travelers from South Africa and nearby countries amid fears omicron could evade vaccines and hinder efforts to reopen economies. Health advocates have pushed wealthy countries to focus instead on boosting access to shots in regions such as Africa that have been left behind.

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