RENNES, Dec 29 — The parents of a 10-year-old girl in France are suing the authorities after their daughter received a Moderna Covid vaccine only allowed for adults over feared side effects, officials said today.

"A complaint has been filed by the father over this,” state prosecutor Cyril Lacombe told AFP, confirming reports in local media.

The ARS regional health service said the girl was mistakenly administered the Moderna shot on December 22 at the vaccination centre in Avranches, a town along the Channel coast.

"Health professionals at the centre realised the mistake immediately, and the doctor in charge consulted with the family,” the ARS said in a statement, noting that "the child is doing well”.

France and several other countries are not letting children receive the Moderna vaccine over a potential risk of myocarditis, or inflammation of the heart muscle.

The rare side effect has been detected in adolescents and young adults, especially males, prompting officials to reserve the Pfizer/BioNTech jab for children aged five to 12.

The ARS said the doctor explained to the parents how to recognise any symptoms of heart inflammation, which is "reversible and not serious”.

Joanny Allombert, director of the Avranches hospital, said the girl was mistakenly put in the wrong waiting queue.

"The girl was asked to sit in the wrong place because there was no more room where she should have been,” he told France Bleu radio. "And things went wrong from there.”

"The nurse made the injection but realised her mistake right away,” he added.

Both the Moderna and Pfizer vaccines rely on messenger ribonucleic acid (mRNA) technology, a cutting-edge process that introduces a "blueprint” of the coronavirus spike protein into the body, which can then recognise it and fight it in case of infection.

Moderna, which has filed for approval of its vaccine for young children with the European Medicines Agency, said in October that clinical trials had shown positive results. — AFP