CHP investigates incident of measles outreach vaccination services at school

  The Centre for Health Protection (CHP) of the Department of Health today (March 3) said that it is investigating and following up on an incident in which a healthcare personnel had administered a combined measles, mumps, rubella and varicella (MMRV) vaccine with a higher-than-normal concentration to a student during an outreach vaccination service at a primary school.

     The CHP has in place a regular monitoring mechanism for vaccination outreach programmes at schools. The CHP's School Immunisation Teams provided the vaccination service at S K H Yan Laap Memorial Primary School for students in the morning of February 27. When the CHP conducted checking on the records of the vaccine administered before finishing the outreach activity on the same day, the CHP found a discrepancy on the number of MMRV vaccine vials used. The CHP is highly concerned about the incident and an investigation was carried out immediately.

     After reviewing all the records, documents and logistics, it was noted that the Immunisation Teams had provided vaccination to over 230 students on that day, which included about 110 students receiving the MMRV vaccine. In preparing a dose of MMRV vaccine, a healthcare personnel did not follow the CHP's protocol in diluting the procedure properly. When providing vaccination to two Primary One students, one of the two students was injected with a dose of higher-than-normal concentration, while the other student was injected with a normal dose.

     The CHP contacted the school on February 28 after a preliminary investigation to explain the incident and approached the parents of the affected students. The CHP has also consulted a paediatric expert and made reference to the safety guide of drugs and vaccination. According to literature and the opinions of the paediatric expert, 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. However, this may lead to an increased risk of an adverse reaction such as a chance of discomfort in the injection site or a higher fever. As the incident involved one of these two students, the CHP has contacted the parents to explain the situation. As a prudent approach, a medical consultation by an expert has been arranged. The two students went back to school as usual without serious physical reactions.

     After a thorough investigation, the CHP confirmed that it was a single incident caused by a human error. The CHP has all along attached great importance to the safety of vaccination. The Immunisation Teams have already reviewed the whole procedure of the school outreach activity and reminded staff to strictly follow the vaccination guidelines and working procedures at all times so as to provide vaccination services to students in a vigilant manner. Meanwhile, the staff member who did not follow the protocol in diluting the vaccine has been suspended from discharging further duty.

     The CHP apologised to the school, students and parents for the inconvenience caused by the incident. A review of the incident has been conducted and training to frontline staff has also been strengthened to prevent a recurrence of similar incidents.

Ends/Friday, March 3, 2023
Issued at HKT 19:18