Regulators in the United Kingdom have authorized the use of Moderna’s vaccine for children aged 6 to 11.

In January 2021, the pharmaceutical giant's vaccine was approved for all adults aged 18 and over. Later that year in August, it was approved for teens aged 12 to 17.

“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,” Medicines and Healthcare products Regulatory Agency chief executive Dr. June Raine said. “The vaccine is safe and effective in this age group.”

No safety concerns were observed in children, and the main side effects were fatigue and arm pain.

Moderna confirmed earlier this month that over 700,000 doses of its COVID-19 vaccine will be rescinded in Europe after a container was found contaminated. The vaccine manufacturer said that only one container was found tainted and that the revocation was merely a safety precaution.

Pfizer released results from a study it conducted Thursday regarding its booster dose efficacy in children aged 5-11. The company said that an additional shot of its mRNA vaccine increased antibodies against Omicron by 36 times for the age group, based on data it conducted from a subset of its 140-person study.

Although COVID-19 infections and deaths have been on the decline for several weeks, the U.K. government has confirmed that it is investigating a COVID variant called XE. It is described as a "recombinant" of the Omicron variant and its relative BA.2.