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Following is a question by the Dr Hon Yeung Sum and a written reply by the Secretary for Health, Welfare and Food, Dr York Chow, in the Legislative Council today (May 23):
Question:
Regarding the immunization service provided by the Department of Health, will the Government inform this Council:
(a) of the morbidity rate of streptococcus pneumoniae disease and meningitis in Hong Kong; the countries which have included the vaccines against these two diseases in their national immunisation programmes; the respective estimated cost and cost-effectiveness of including each of these two vaccines in the Childhood Immunisation Programme (CIP);
(b) whether it will consider including the above two vaccines in CIP; if it will, of the details; if not, the reasons for that; and
(c) when vaccine against hepatitis B was first included in CIP; the estimated number of people in Hong Kong who have not been inoculated with such vaccine; whether it will consider inoculating these people with such vaccine; if it will, of the details; if not, the estimated number of new cases of hepatitis B in Hong Kong in the coming five years and the medical expenses to be incurred?
Reply:
Madam President,
(a) The incidence rate of invasive pneumococcal diseases in Hong Kong was reported to be 2.3 per 100 000 population, as compared with 24 per 100 000 population in the United States before the introduction of pneumococcal vaccine there.
Locally, the annual incidence of invasive meningococcal infections was between 0.03 and 0.21 per 100 000 population in 1990-2006, as compared with 0.8-1.3 per 100 000 population in the United States before the introduction of meningococcal vaccine there.
Some of the countries that have included or not included pneumococcal and meningococcal vaccines in their childhood immunisation programmes are shown in Table 1.
The cost of including the vaccines into the childhood immunisation programme depends on various factors, such as the type of vaccine used, the mode of vaccination and the supply and demand of the vaccines. It is difficult to estimate the related cost at present.
(b) The Department of Health (DH) receives advice from the Scientific Committee on Vaccine Preventable Diseases (the Committee) under the DH's Centre for Health Protection in updating the childhood immunisation programme of Hong Kong. The Committee regularly reviews the local epidemiology of diseases, scientific development and application of new vaccines as well as their formulations and cost-effectiveness, and the experiences of other health authorities in making recommendations to the DH.
The incidence of invasive meningococcal infections is relatively low in Hong Kong. About half of the meningococcal infections were caused by Neisseria meningitidis serogroup B, which is not protected against by the available quadrivalent meningococcal vaccine (which protects against serogroups A, C, Y and W-135). Furthermore, the duration of protection of the vaccine is short, and it is relatively ineffective in children aged under 2. Therefore, the Committee concludes that there are insufficient justifications to include the quadrivalent meningococcal vaccine in the Childhood Immunisation Programme of Hong Kong. Taking the Committee's recommendation, the Administration has no plans to introduce meningococcal vaccine into the local childhood immunisation programme.
Inclusion of vaccines against invasive pneumococcal diseases in the Childhood Immunisation Programme for new born babies and the cost effectiveness of such a programme are being reviewed by the Committee.
(c) Hepatitis B is a type of viral hepatitis that leads to acute hepatitis. Infected people may also develop a carrier state, which is associated with chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. The risk of carriage varies with the age of infection. It occurs in 90-95% of infants infected by perinatal transmission (mother-to-child transmission at or around the time of delivery), 30% of children aged 1 to 5, and 5-10% of the youth and adults.
The hepatitis B virus is found in the body fluids of an infected patient or a carrier. It is mainly spread through perinatal, blood or sexual contact. Perinatally acquired hepatitis B infection was regarded as the most important cause of the high carrier rate in Hong Kong.
In Hong Kong, hepatitis B vaccine has been incorporated into the Childhood Immunisation Programme for newborn babies since 1988 to cover all children born since January 1986. Babies get the immunisation at birth in hospitals, followed by immunisations at Maternal and Child Health Centres at one and six months of age. Besides, inoculators of the DH also pay annual visits to all primary schools and check the immunisation status of school children. Those who have not been immunised with the hepatitis B vaccine previously will be immunised. The vaccination coverage rates have been maintained at more than 98% at both Primary 1 and 6 in the past 10 years. Therefore, the majority of the people aged 21 or below are immunised against hepatitis B infection.
Acute hepatitis B infection is one of the statutorily notifiable diseases in Hong Kong. The annual number of acute hepatitis B notified in the past 5 years was about 98-130. The breakdown is shown in Table 2.
We expect that the number of new cases in the next few years would be within this range.
As the clinical presentations of hepatitis B infection may range from asymptomatic, acute hepatitis, chronic hepatitis, cirrhosis and liver caner, it is difficult to estimate the medical expenses.
Ends/Wednesday, May 23, 2007
Issued at HKT 12:23
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