Scientific Committee on Vaccine Preventable Diseases reviews latest seasonal influenza situation and vaccine effectiveness
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At the meeting, the SCVPD noted that while the local influenza activity remains elevated, the percentage that tested positive for seasonal influenza viruses among the respiratory specimens received by the CHP's Public Health Laboratory Services Branch has decreased from 30.10 per cent in the week ending January 19 to 25.48 per cent in the week ending January 26. The number of influenza-like illness (ILI) outbreaks has dropped markedly from the peak of 211 recorded last week to 21 in the first four days of this week (as of January 29).
Meanwhile, the overall admission rate with principal diagnosis of influenza in public hospitals decreased from 1.53 to 1.15 cases per 10,000 of the population from the week ending January 19 to that ending January 26. Among children aged below 6, the rate went down from 10.94 to 7.65 cases per 10,000 of the population in the corresponding period.
During the same period, the rate of the ILI syndrome group at accident and emergency departments slightly decreased from 254.1 (per 1,000 coded cases) to 246.1, while the average daily number of laboratory confirmed influenza cases in public hospitals dropped steadily from an average of 312 per day during January 16 to 22 to 234 during January 23 to 29.
At today’s meeting, members also examined the latest data on the vaccine effectiveness of the SIV for the current season. The SCVPD noted that the circulating influenza A viruses were so far antigenically similar to the vaccine components of the 2018/19 SIV.
The CHP has continued to collaborate with private medical practitioners participating in its sentinel surveillance system to collect data to estimate the vaccine effectiveness of SIV in the current influenza season. Preliminary results showed that SIV offers approximately 60 per cent protection against laboratory-confirmed influenza infections in local primary care setting in the 2018/19 season. The CHP will continue to collect data from the private medical practitioners in this season to monitor the vaccine effectiveness of SIV.
At the meeting, members also listened to a presentation by the University of Hong Kong on the findings of a recent hospital-based study on effectiveness of SIV against influenza hospitalisation in children in Hong Kong. The early season estimate revealed that influenza vaccination effectiveness was about 90 per cent, meaning that the chance of being hospitalised due to influenza was reduced by 90 per cent in children who had received the influenza vaccine when compared to those who had not received the vaccine this season.
The SCVPD reaffirmed that the SIV for the current season is highly effective in preventing influenza in both out-patient and in-patient settings. Also, the SCVPD noted that the majority of severe influenza cases had not received the SIV for this season. As the local seasonal influenza activity is expected to remain elevated in the period ahead, members agreed that people aged 6 months or above who have not yet received the SIV for this season are recommended to get vaccinated against seasonal influenza for personal protection as soon as possible, in particular, children, people aged 50 to 64 years, the elderly and those with underlying illnesses.
For more information, the public may call the CHP's hotline (2125 2125) or visit the CHP's Vaccination Schemes page.
Ends/Wednesday, January 30, 2019
Issued at HKT 19:39
Issued at HKT 19:39
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