Moderna has been approved for jabs in children aged six to 11 by the Medicines and Healthcare products Regulatory Agency (MHRA).
It will still need to be considered by the Joint Committee on Vaccination and Immunisation (JVCI) as to whether it will be offered to the age group.
The jab, also known as Spikevax, is already been approved for children over 12. The European Medicines Agency gave it the green light for kids aged six to 11 on March 2, the Mirror reported.
Pfizer is currently approved for use in kids' vaccinations starting from the age of five.
It comes as the MHRA approved the easy-to-store Covid vaccine for adults up to 50 years of age from the French firm Valneva.
Covid infections have fallen across most of the UK after a recent surge in cases thanks to the Omicron BA.2 variant, according to figures from the Office for National Statistics (ONS).
However, it is too early to tell if it means we are past the peak of the latest variant surge.
Prevalence of the virus remains high across the country, the ONS said.
A total of 4.4 million people in private households in the UK were likely to have had coronavirus in the seven days to April 9.
This is down week-on-week from 4.9 million, which was the highest total since estimates began.
England has seen infections drop for the first time in six weeks, with 3.8 million people likely to have had coronavirus last week, or around one in 14.
The figure dropped down from 4.1 million the previous week, or one in 13, according to the ONS.
Scotland and Northern Ireland have also seen levels fall.
But in Wales infections have risen for the sixth successive week, with 231,900 people estimated to have had the virus last week, or one in 13 - up slightly from 230,800, also one in 13.
Dr June Raine, MHRA Chief Executive, said: "I am pleased to confirm that that the COVID-19 vaccine made by Moderna, ‘Spikevax’, has now been authorised in Great Britain in 6 to 11-year-olds. The vaccine is safe and effective in this age group.
"We have in place a comprehensive surveillance strategy for monitoring the safety of all UK-approved COVID-19 vaccines and this surveillance includes those aged 6 to 11.
"It is for the Joint Committee on Vaccination and Immunisation (JCVI) to advise in due course on whether 6 to 11s should be offered vaccination with the COVID-19 vaccine made by Moderna as part of the deployment programme."
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