The public is urged to get vaccinated against influenza (flu) as the flu season has arrived earlier than usual. The 2026 influenza season started in the week of 9 March 2026. The flu season is declared when the rate from the National Institute for Communicable Diseases (NICD) sentinel surveillance exceeds the defined level for the season to start and is sustained for two consecutive weeks. While this year’s season has started earlier than in recent years, it is similar to 2025, when the season started in the week of 24 March.
The 2026 respiratory syncytial virus (RSV) season also started in the week of 9 March 2026. The fact that both the flu and RSV seasons are starting at the same time means clinicians could potentially see a high burden of patients with respiratory illness in medical facilities in the coming weeks.
Influenza A(H3N2), A(H1N1)pdm09 and influenza B are common seasonal influenza strains in humans. The majority of people with influenza present with mild illness, which usually resolves within three to seven days. However, influenza may cause severe illness, leading to hospitalisation or possibly death, especially among those at risk of severe illness or complications.
Influenza vaccination is recommended to protect against infection and severe illness. Ideally, the influenza vaccine should be administered prior to the start of the influenza season as it takes about two weeks for an adequate immune response to develop following vaccination. However, it is not too late to vaccinate once the season has begun. The influenza vaccine will be available in pharmacies from the first week of April. The early start to the season means that this year, the vaccine is only becoming available as the season is getting started, so members of the public who fall into groups at high risk for severe influenza are urged to get their vaccines as soon as possible.
Weekly updates on influenza and other circulating respiratory viruses such as RSV, COVID-19, and pertussis are available from the NICD. Click here to visit the page.
