Influenza situation
October marks the start of the northern hemisphere influenza season.
Influenza activity has started to increase in many countries. Public health measures taken to reduce transmission of COVID-19, also reduced influenza activity. Now that these measures have been removed, both viruses may transmit more easily. The co-circulation of influenza a SARS-CoV-2 viruses raises the possibility of a more severe winter respiratory virus season.
Influenza burden
Influenza is a serious disease. Around a billion people become sick with influenza every year, with 3 to 5 million severe cases and 290 000 to 650 000 deaths.
Many people miss work or school, and feel unwell, with a fever, cough, headache, muscle and joint pain, sore throat and a runny nose. Most people recover within a week, but the cough can be severe and can last 2 weeks or more. Very old and young people, those with underlying metabolic or cardiovascular conditions, and vulnerable populations can be at risk of more severe complications of influenza,
Vaccination
Influenza vaccination remains an essential intervention for preventing influenza disease and reducing disease severity and mortality.
WHO recommends the following groups for priority use of influenza vaccines: health workers, individuals with comorbidities and underlying conditions, older adults, and pregnant women; and children (depending on national disease goals, capacity and resources, epidemiology, national policies and priorities, and disease burden).
WHO considers the coadministration of a seasonal influenza vaccine with any dose of a COVID-19 vaccine is acceptable, and if the vaccines are administered during the same visit, WHO recommends using the contralateral limb for injection.
The WHO Global Influenza Surveillance and Response System has recently announced the recommended composition of influenza virus vaccines for use in the 2023 southern hemisphere influenza season.
Other measures apart from vaccination
Apart from vaccination, personal measures such as hand hygiene, physical distancing, respiratory etiquette, mask use, and staying home when sick, which are effective in limiting COVID-19 transmission, can be also effective for limiting influenza transmission.
Pandemic potential of influenza and importance of surveillance
Additionally, countries continue to report human cases of infection with avian and swine influenza viruses (zoonotic influenza), indicating the reality that an influenza virus with pandemic potential (IVPP) could emerge at any time.
Influenza surveillance systems are critical to monitoring and understanding globally circulating viruses.
As such, WHO urges countries to maintain vigilance for influenza epidemic and pandemic threats.
The WHO Global Influenza Surveillance and Response System (GISRS), which is celebrating its 70th anniversary this year, serves as the global mechanism and platform for virological surveillance.
Since the beginning of the COVID-19 pandemic, WHO has also encouraged Member States to integrate testing of samples for SARS-CoV-2 into existing influenza sentinel surveillance systems given the similarity of symptoms in people infected with these viruses.