Four children were given Covid vaccine overdoses of more than twice the approved amount, it has emerged.
It is believed the youngsters were aged between five and 11, and were clinically vulnerable.
Scottish Labour’s health spokeswoman Jackie Baillie last night called for an urgent inquiry.
She said: “Kids getting adult doses is pretty serious, especially when it is not a one-off.
“We don’t know the implications and there needs to be proper monitoring of these children. They can’t be left to cope with quite severe side effects on their own.
“There also needs to be an urgent inquiry.”
The mum of a 10-year-old boy told how his arm became sore almost immediately after he received his jab at the Ally McCoist Centre in East Kilbride. Hours later, he developed stomach pains, diarrhoea and had a splitting headache.
During the night, his mum saw a vein in the boy’s neck pulsing and he was still suffering side-effects almost a week later.
She received a call from a senior doctor with NHS Lanarkshire who told her: “There has been an error but I think he is going to be OK.”
He said instead of being given 10micrograms of vaccine mixed with saline solution, her son had been given 25.7micrograms.
The medic told the mum it was “highly unlikely” this would lead to any problems but gave her his mobile number and said if the boy developed severe symptoms to take him to hospital.
The boy has a rare condition called chiari malformation, where the lower part of the brain pushes down into the spinal canal. He has already had two brain operations and may need a third.
The mum said: “A doctor told me adult and child doses are kept in the same fridge and are not colour coded. It’s not surprising a mistake was made. Check the dose your child is being given.”
A Scottish Government spokeswoman said: “We’re aware a small number of children received a higher than recommended dose of the Pfizer vaccine instead of the paediatric formula.
“NHS Lanarkshire has assured us the error was quickly identified, reported and actions were put in place to ensure the affected parents were fully informed of what had happened.
“NHS Lanarkshire has apologised to the affected young people and their families for any worry caused by this error.
“It has undertaken the monitoring required when someone is given more than the recommended dose of a Covid-19 vaccine.”
North Lanarkshire health and social care associate medical director Dr Mark Russell said: “We would like to apologise to the
child and the three other children who received a dose of the Pfizer Covid-19 vaccine larger than would normally be given for their age.
“I contacted the families as soon as we discovered what had happened to offer advice and support, and have monitored
them since.
“We’ve reviewed processes at vaccination centres and are sharing the learning across health boards to reduce the risk of this happening again.”
