2023 - 2024 Influenza (Flu) Season

Preparing for the 2023-2024 Flu Season in Hong Kong

The 2023-2024 flu season in Hong Kong is anticipated to present unique challenges. The population's weakened immunity to influenza, owing in part to extended public health measures from previous years, is expected to contribute to a surge in cases.

When is Flu Season in Hong Kong?

The peak flu season in Hong Kong generally occurs between January and March, and again from July to August.

Why Might the 2023-2024 Flu Season Be More Intense?

Influenza activity in Hong Kong has shown a significant increase since March 2023, exceeding baseline thresholds by early April. This suggests that the population is more susceptible to influenza than before, possibly leading to more infections and a higher proportion of severe cases.

The weekly percentage of respiratory specimens testing positive for influenza A or B viruses has risen markedly since March 2023. Notably, around 80% of these detections were of the influenza A(H1) virus. In public hospitals, the admission rate for cases with a principal diagnosis of influenza has also exceeded baseline levels. These increases are most prominent among specific age groups: children under 12, adults between the ages of 50 and 64, and the elderly aged 65 or above.

Moreover, the number of severe influenza infections has risen dramatically, with more than 25 cases recorded in just the second week of April. This is a significant increase compared to the sporadic cases observed during January to February of the same year. Alarmingly, only about 20% of these severe cases had received the seasonal influenza vaccine for the 2022-2023 season.

How shall I prepare for the flu season?

Influenza can be a severe illness, especially for vulnerable populations. Here are some recommendations:

Here’s what you can do to be prepared for the 2023-2024 flu season:

1. Get Vaccinated: The flu vaccine is clinically proven to reduce the risk of contracting the illness and experiencing severe symptoms. This applies to both adults and children. It's recommended to get the flu vaccine early in the season, preferably around September or October.
   
2. What to Do if You Fall Ill: If you exhibit symptoms like fever, cough, shortness of breath, and muscle aches, consider visiting your doctor for guidance and potential antiviral treatment.
3. Protect Against Other Illnesses: Ensure your vaccinations are up-to-date. Regular handwashing, disinfecting surfaces, and staying home when unwell are all good practices. Winter is also the season for other contagious viral illnesses such as Respiratory Syncytial Virus or RSV (common for children) and Norovirus (a stomach bug). To ensure that your immunity to common communicable diseases is in the best possible shape, you can review your vaccine status with your doctor. More information on the vaccines you should have can be found on our vaccine page.

As we approach the 2023-2024 flu season in Hong Kong, it's essential to take precautions to protect ourselves and our community. Early vaccination and good hygiene practices can make a significant difference.

References

1. Scientific Committee on Vaccine Preventable Diseases. (2023, April 19). Recommendations on Seasonal Influenza Vaccination for the 2023-2024 Season in Hong Kong. Retrieved September 6, 2023, from https://www.chp.gov.hk/files/pdf/recommendations_on_seasonal_influenza_vaccination_for_the_2023_24_season_in_hong_kong_19apr.pdf