LCQ3: Seasonal Influenza

     Following is a question by the Hon Chan Hok-fung and a reply by the Secretary for Health, Professor Lo Chung-mau, in the Legislative Council today (June 5):

Question:

     It has been reported that the peak season of seasonal influenza (influenza) persists. Some experts in respiratory medicine have predicted that Hong Kong's winter and summer influenza seasons may be linking up, and have called on high-risk cohorts to receive influenza vaccine as soon as possible. In this connection, will the Government inform this Council:

(1) of the numbers of severe cases and fatalities involving children infected with influenza as well as the death rates in the past three years, and whether those children had received influenza vaccine, together with a tabulated breakdown by age (i.e. aged under three, between three and five, between six and eight, and between nine and 11);

(2) as it has been reported that some experts have pointed out that children born during the COVID-19 epidemic are less resistant to influenza viruses, and have called on the parents concerned to get their children vaccinated against influenza as soon as possible, and that the types of vaccines required for infants and children are recommended under the Government's Hong Kong Childhood Immunisation Programme, whether the Government will include influenza vaccines in the programme; if so, of the timetable; and

(3) as it has been reported that some medical doctors have pointed out that with global warming, the chances of new endemic diseases raging the world will be increasingly higher, whether the Government has conducted drills on a regular basis in order to cope with an extreme scenario of an influenza outbreak similar to the COVID-19 epidemic; if so, of the details?

Reply:

President,

     Hong Kong has entered the influenza season since January this year until now, the Government has stayed vigilant and implemented a series of measures in respect of virus surveillance, protection of high-risk groups, vaccination, service demand, etc. The Government has also been constantly reminding the public to have better protection. For instance, the Centre for Health Protection (CHP) and the Hospital Authority (HA) had held press conferences jointly in January and April this year; and the HA also held a press conference again in February to explain the measures to respond to the service surge of public hospitals. Further to the briefing to the Panel on Health Services of the Legislative Council in October last year on the relevant preparation work for influenza, the Government will also report to the Panel on the latest situation of influenza next Friday (June 14).

     "Prevention is better than cure". The Government has been strongly encouraging the public to receive influenza vaccination, and providing subsidised or free seasonal influenza vaccination (SIV) to the public. With the joint effort from various parties, in 2023-24, a total of more than 1.85 million doses of SIV were administered under all vaccination programmes, representing an increase of about 20 per cent when compared with the 2022-23 season, which is a record high.

     Influenza viruses are constantly changing, therefore, influenza vaccines need to be updated annually. The World Health Organization (WHO) normally announces in February to March of the year the proposed strains for influenza vaccines to be used in the Northern Hemisphere, preparing for the influenza season starting at the end of year. After the announcement of strain recommendation, the manufacturers can start preparing for the production of vaccines for arranging the vaccination in the region in the Northern Hemisphere at the end of the year. The Hong Kong Special Administrative Region Government normally starts the SIV programmes in October (viz. upon the availability of vaccines for the new season). These vaccines will usually expire around next July/August and the programmes will also come to an end at that time. 

     Therefore, "Early vaccination! October is the best timing". October is the most ideal timing for receiving SIV. The earlier citizens get vaccinated, the better they can make use of the SIV for comprehensive protection against influenza in the coming year. With the transit of the dominating virus strain (from the earlier A(H3) to the recent A(H1)) in the current influenza season, the duration of winter influenza season has lasted for a longer time until now (i.e. June). Members of the public who have not received the SIV can still get vaccinated before the expiry of the influenza vaccine of this influenza season (i.e. July/August). Nevertheless, please remember that even if you get vaccinated now, you should still take the latest SIV in the new SIV programme (viz. from October this year), so as to get protection in the influenza season in the next year.

     In consultation with the Department of Health (DH), the reply to the question raised by the Hon Chan Hok-fung is as follows:

(1) Information on severe paediatric influenza-associated complication and death cases is at Annex. Over the past three years, in particular before early 2023, relevant seasonal influenza figures remained at very low levels due to various social and personal protective measures, in particular mask wearing, amid the COVID-19 epidemic. The number of severe cases was close to zero, and the number of death cases in 2020 to 2022 was basically zero. In this connection, pre-COVID-19 period figures (i.e. 2017 to 2019) are also provided in the Annex for a comprehensive comparison. According to the data, the number of severe cases in the first half of 2024 is comparable to that in the pre-COVID-19 period (i.e. the figures in the first half of 2019). When looking at these figure, it is more important to note that most of the severe and fatal cases did not receive influenza vaccine. For the figures in the first half of 2024, 20 out of 26 severe cases did not receive influenza vaccine, which illustrates the importance of vaccination again.

(2) As for the Hong Kong Childhood Immunisation Programme (HKCIP), at present, the HKCIP targets 12 special communicable diseases (Note). In general, children can achieve long-term or life-long immunity after completing one dose or one course of vaccination, which is very different from SIV. Annual vaccinations are required for SIV. And not only children should get vaccinated for SIV, adults, in particular the elderly, should also get vaccinated annually. The Scientific Committee on Vaccine Preventable Diseases (SCVPD) under the CHP holds regular meetings and gives science-based advice and recommendations to the CHP in a timely manner regarding the types of vaccines to be in-corporated into the HKCIP.

     In regards to the SIV, the SCVPD will examine the scientific evidence on the influenza vaccines, local, neighbouring and overseas epidemiology of the seasonal influenza every year to propose various priority groups to receive vaccination. Currently, children and adolescents aged six months to under 18 years are included in the priority groups. The Government has been providing the SIV under the Government Vaccination Programme and the Vaccination Subsidy Scheme. Eligible children and adolescents can receive free or subsidised SIV in public or private clinic. Moreover, the Government provides influenza vaccination proactively to students at participating schools through the school outreach vaccination programmes. This year, around 70 per cent of secondary schools, around 95 per cent of primary schools and around 80 per cent of kindergartens and child care centres have enrolled in the outreach programmes.

     Although the SIV is not part of the HKCIP, the DH has been promoting the SIV to parents of the infant and young children through its service points and collaboration with schools. In 2023-24, more than 530 000 doses of SIV have been administered for children and adolescents, reaching a record high and an increase of about 37 per cent comparing with the same period of last year. The vaccination rate is 53 per cent. 

 (3) Finally, in response to the major outbreaks of communicable diseases, the Government has been preparing to reduce risk of human infection. Measures include regular public health exercises and drills and provision of trainings on infection control. Among which, public health exercises and drills cover different scenarios, including avian influenza, novel influenza or novel diseases. The latest exercise code-named "Prehnite" was conducted in November 2023 which included a table-top exercise and a ground movement exercise to mainly test the preparedness of relevant government departments in handling imported cases and local transmission of communicable diseases, and arrangement of large-scale evacuation operation. The CHP also proactively participates in exercises co-organised in the Guangdong Province, Hong Kong and Macao, as well as exercises conducted by the WHO, with a view to strengthening collaboration with local and international partners.

     Thank you, President. 

Note: 12 communicable diseases including tuberculosis, hepatitis B, polio, tetanus, pertussis, measles, diphtheria, mumps, rubella, chickenpox, pneumococcal disease and human papillomavirus infection.