CHP responds to media enquiry on respiratory syncytial virus
************************************************************
RSV is included in routine surveillance
-------------------------------------------
The CHP monitors the activity and disease burden (e.g. mortality and hospitalisation rates) of major local respiratory diseases, including RSV, through a series of surveillance systems. For laboratory surveillance, the CHP's Public Health Laboratory Services Branch regularly conducts Polymerase Chain Reaction (PCR) tests for RSV on respiratory specimens. Additionally, the CHP monitors RSV-associated hospitalisations in public hospitals based on principal discharge diagnoses and tracks upper respiratory infection outbreaks in schools and residential care institutions. The CHP announces number of positive detections and percentage weekly, and releases the latest epidemiological situation via press releases and online publications periodically.
Influenza-associated hospitalisation rate far exceeds that of RSV
-------------------------------------------------------------------------------
RSV can cause respiratory tract infections, including infection of the airway, lungs and middle ear. The virus can be transmitted by direct contact with infectious secretions or droplets, or indirectly through contaminated hands, eating utensils or articles freshly soiled by nasal or throat discharges of an infected person. Most people experience only mild symptoms after infection.
The epidemiological pattern of RSV is difference from that of the seasonal influenza. In general, influenza has an obvious seasonal pattern that a peak usually happens in winter and summer; RSV does not have a clear seasonal feature. In some of the years, a peak may happen between May and August, while no regular patterns can be found in some other years. This year, no seasonal peak of RSV has been shown. Laboratory surveillance data revealed that the percentages of specimens tested positive for RSV over the past 12 weeks ranged between 2.5 per cent and 3.5 per cent, which are higher than that of the first-half year when less than 1 per cent was recorded but far lower than 8 per cent to 10 per cent when a peak was recorded in the past.
On the other hand, RSV is similar to influenza and COVID-19, with the elderly and young children being the most affected groups. Fatal cases primarily occur among the elderly, with mortality rates increasing with age. The hospitalisation rate associated with RSV is also higher for elderly persons aged 75 or above.
The CHP's analysis indicated that between January 2023 and June 2025, the average annualised mortality rates associated with RSV among elderly persons aged 75 or above was 10.3 per 100 000 population, which is lower than that of the rate of 80.2 per 100 000 population for seasonal influenza. The hospitalisation rate associated with RSV among elderly persons was also lower than that for seasonal influenza. In recent years, the weekly influenza-associated hospitalisation rate during the peak of influenza seasons was approximately 10 per 100 000 population, while the hospitalisation rate for RSV generally remained below 2 per 100 000 population. The average cumulative hospitalisation rate for influenza among elderly persons was 3.7 times that of RSV.
Prevention of RSV infection
------------------------------
Although the overall disease burden of RSV is lower than seasonal influenza, it is still a respiratory infectious disease with public health significance. The prevention of RSV and other respiratory diseases (such as influenza) are therefore equally important. The public should maintain good personal and environmental hygiene, and wear a surgical mask to prevent transmission if they present with fever and respiratory symptoms. The public should also keep the room well-ventilated and if they develop respiratory symptoms, wear a surgical mask, stay home from work or school, avoid crowded places and seek medical attention as soon as possible.
Regarding vaccination, the Scientific Committee on Vaccine Preventable Diseases (SCVPD) under the CHP regularly reviews the epidemiological situation of local vaccine-preventable diseases, the latest recommendations of the World Health Organization (WHO), scientific developments and evidence on vaccines, updates on vaccine components, cost-effectiveness studies, as well as actual experiences of other health authorities. It provides relevant vaccination recommendations to the DH from a public health perspective.
During the meeting in January this year, the SCVPD discussed the use of RSV vaccines for elderly persons. After thoroughly reviewing local epidemiological data on RSV disease; the scientific data on the efficacy, safety and potential adverse effects of the vaccines, the experts were of the view that the two RSV vaccines currently registered in Hong Kong are safe and effective.
Regarding vaccination for elderly persons, as specific recommendations from the WHO and local data from the cost-benefit perspective are pending, universal RSV vaccination for elderly persons is not recommended at the moment. The SCVPD considered that elderly persons may consult their family doctor for professional advice to understand the benefits, risks and necessity of vaccination. Based on the doctor's assessment, they can make decisions on whether to proceed with RSV vaccination for personal protection. The Health Bureau has commissioned The University of Hong Kong to conduct an analysis on the cost-benefit of the RSV vaccine. Upon completion of the cost-benefit analysis, the SCVPD will discuss again the issue on RSV vaccination based on the relevant analysis results and latest scientific evidence. The recommendations of the SCVPD in January are available on the CHP website.
The CHP will continue to closely monitor major local respiratory diseases and regularly publish data. It will also remind healthcare professionals and members of the public of relevant public health information and recommendations in a timely manner through appropriate channels.
Ends/Thursday, October 16, 2025
Issued at HKT 21:50
Issued at HKT 21:50
NNNN