A healthcare worker has been suspended after a Hong Kong schoolchild was injected with a higher-than-normal dose of measles vaccine, health authorities have said.

But the Centre for Health Protection highlighted on Friday that the pupil at SKH Yan Laap Memorial Primary School in Kwai Chung did not develop any adverse reactions after the injection and returned to school after being examined by a expert in paediatrics.

“After a thorough investigation, the Centre for Health Protection confirmed that it was a single incident caused by a human error,” a government spokesman said. “The staff member who did not follow the protocol in diluting the vaccine has been suspended from discharging further duty.”

SKH Yan Laap Memorial Primary School, where a child was given an overdose of measles vaccine by mistake.

Health authorities also apologised to the affected child, the school, pupils and parents for the inconvenience caused by the incident and emphasised it had boosted training for frontline staff to prevent a recurrence.

The problem was discovered after the centre spotted a discrepancy in the number of vaccine vials used as it ran a vaccination clinic at the school on Monday.

Healthcare staff were at the school to give the combined measles, mumps, rubella and varicella (MMRV) vaccine to 110 pupils.

It was found during a preliminary investigation that a healthcare worker did not follow the centre’s protocol for dilution of the vaccine and gave one of two pupils who got a jab from the same vial a higher-than-normal dose.

The spokesman said the other child’s jab was at the correct strength.

The two children were seen by an expert as a precaution, but neither were found to have suffered any serious reactions.

“Administering vaccines with a greater than recommended dose to an individual will not usually affect the overall immune response or protection afforded by the vaccine,” the centre said.

The children’s parents were notified of the incident.

The government spokesman said health officials had reviewed procedures for the schools’ vaccination programme and reminded staff to always follow guidelines and working procedures for vaccination.

The MMRV vaccine has been included in the city’s childhood immunisation programme since 2013.

It is given to children aged one year, with a mop-up campaign in place for primary school pupils who have not completed the two shot vaccination process.