The Department of Health today said that it is investigating and following up on an incident in which the pneumococcal vaccine was mistakenly administered to two children who were originally scheduled to receive the hepatitis B vaccine at the Tin Shui Wai Maternal & Child Health Centre (MCHC).

The department has explained and apologised to the parents of the affected children.

So far, there has been no adverse reaction in the children, and pediatricians have assessed that the incident would not pose a health risk to them.

In accordance with the regular monitoring mechanism, the Tin Shui Wai MCHC reviewed the vaccination records at the end of the service session on February 17 and found that the number of vaccines administered during the session between 4pm and 5.30pm that day did not correspond to the number of vaccines that should have been administered.

Seven children should have received the hepatitis B vaccine during the said period.

Upon review of the number of vaccines administered, it was found that there were two doses of the hepatitis B vaccine left unused and two extra doses of the 15-valent Pneumococcal Conjugate Vaccine (PCV15) that were used. After double-checking the vaccine stock, it was found that two children had been incorrectly immunised with PCV15 during that period.

A preliminary investigation revealed that the children vaccinated during that period were between one month and seven months old.

Under the Hong Kong Childhood Immunisation Programme (HKCIP), children receive the first hepatitis B vaccine dose within 24 hours of birth, followed by the second and third doses at one month and six months of age respectively; for PCV15, the first two doses should be administered at two months and four months of age, and a booster dose should be given at 12 months of age.

The department's healthcare staff contacted the parents of the seven children to apologise and explain the follow-up action.

Arrangements have also been made for paediatricians to conduct detailed examinations of the children as soon as possible, to provide them with an additional dose of hepatitis B vaccine at an appropriate time, and to complete three doses of PCV15 vaccinations in accordance with the HKCIP.

The investigation is ongoing. A preliminary probe indicated that the incident was caused by human error.

The department has instructed all MCHCs to strengthen the training of frontline staff to ensure that they strictly follow the internal guidelines on checking vaccine and patient information before administering vaccines, and verifying the information with the person accompanying the child for vaccination to prevent the recurrence of similar incidents.

The department reiterated its sincere apology to those affected. The nursing staff involved in the incident have been suspended from vaccination duties. If any staff misconduct is confirmed, the case will be dealt with in accordance with the established procedures.