Seasonal influenza and its prevention

Seasonal influenza is an acute respiratory infection caused by influenza viruses that circulate in all parts of the world.

It is a serious condition that can lead to severe complications such as heart attacks and strokes and has a huge human, societal, and economic impact.

Flu is a contributing factor to five out of the top 10 deaths globally, with 3 to 5 million severe influenza cases reported worldwide.

The WHO estimates that flu may be responsible for an estimated 290,000 to 650,000 respiratory deaths per year worldwide, with a global burden of about 10 million influenza-related hospitalisations every year.

According to a recent study, one is 10 times more likely to have a heart attack in the week after being diagnosed with the flu and eight times more likely to have a stroke.

People over 65 years of age are most susceptible to flu and its complications, because the immune system deteriorates with age (immunosenescence), experiencing a higher risk of influenza-associated morbidity and mortality. 50-70% of hospitalisations occur in people aged over 65 and 70-85% of flu-related deaths occur in this age group.

Those with other chronic conditions such as asthma, chronic obstructive pulmonary disease (COPD), heart disease, and diabetes are at greater risk of flu-related complications than the general population.

For example, people with heart conditions are 10 times more likely to die from flu complications and diabetes triples the risk of hospitalisation for flu complications and quadruples the risk of intensive care unit (ICU) admission once in hospital. Furthermore, flu can cause increased exacerbations in asthma and COPD patients.

Because age increases susceptibility to infection, older adults are the most at risk for influenza infection and serious outcomes. 

Influenza infection can contribute to functional decline, or a senior’s inability to recover back to full prior functional capacity once the infection has passed. Adults aged over 65 represent 9 in 10 influenza-related deaths and 63% of influenza-related hospitalisations.

Flu vaccination is the most effective way to protect yourself, those around you who may be more vulnerable to the disease and the wider economy. 

Flu vaccination is especially important for people at high risk of flu complications, and for people who live with or care for the people at high risk. Hence, WHO recommends annual vaccination for:

• Pregnant women at any stage of pregnancy
• Children aged between 6 months to 5 years.
• Elderly individuals with chronic medical conditions
• Individuals with chronic medical conditions
• Health-care workers