British Prime Minister Boris Johnson speaks at a COVID-19 press conference in the Downing Street media briefing room in London, Britain, Dec. 15, 2021. Britain reported 78,610 new coronavirus cases, the highest daily number since the start of the pandemic, bringing the total number of coronavirus cases in the country to 11,010,286, according to official figures released Wednesday. (Simon Dawson/No. 10 Downing Street/Handout via Xinhua)

British regulators on Wednesday approved Pfizer's COVID-19 vaccine for use in children aged 5 to 11, as the country reported more than 100,000 new daily cases for the first time as Omicron surged.

The developments came after the government said it was cutting the isolation period required for positive cases while Wales and Northern Ireland followed Scotland in unveiling new post-Christmas curbs, primarily around hospitality and large events. 

Britain's Medicines and Healthcare products Regulatory Agency (MHRA) said it had approved a new lower-dose formulation of the Pfizer-BioNTech shot after finding it was "safe and effective" for children aged 5 to 11.

MHRA chief executive June Raine said there was "robust evidence to support a positive benefit risk for children in this age group."

The "overwhelming majority" of reported side effects from the two-shot "age-appropriate" jab related to mild symptoms, such as a sore arm or a flu-like illness, she added. 

The Joint Committee on Vaccination and Immunisation, which advises UK health departments on immunization, said it was now recommending a primary course of the vaccination be offered to some within the age group.

Britain is in the midst of a stepped-up booster campaign, as it tries to minimize the impact of weeks of rising Omicron infections.

On Wednesday the country surpassed 30 million third doses administered as it aims to offer the additional jab to all adults before the end of 2021.

The variant is now the dominant strain of the virus across the UK as daily new cases reach record levels.

It announced 106,122 new infections Wednesday, the highest figure since mass testing began in the summer of 2020.

Earlier, the government said people who have tested positive can stop self-isolating after seven days instead of 10 if they have taken two negative lateral flow tests.

Amid the skyrocketing case numbers, it could potentially allow many more to join family Christmas celebrations.

Hours later, devolved governments in Cardiff and Belfast announced new curbs from Sunday - leaving just England with no imminent restrictions unveiled.

In Wales, socializing in pubs, cinemas and restaurants will be limited to groups of six people or less, while mandatory table service and providing contract tracing details will return.

In Northern Ireland, nightclubs will have to close at 8 pm, alongside guidance to limit contacts with different households.

It follows Scotland announcing renewed rules there Tuesday, which also come into force on Sunday for at least three weeks, and cap attendance at outdoor events at 500.

The move means the pandemic has forced the cancelation of Edinburgh's popular New Year's Eve street party for the second successive year.

AFP