Comprehensive Guide to Influenza and Its Vaccination

Influenza, commonly known as the flu, is a contagious viral infection that impacts the respiratory system. Since antibiotics do not treat viral illnesses, management of the flu focuses on relieving symptoms such as fever and muscle aches through medications, bed rest, and hydration. Antiviral drugs can shorten the illness if administered within the first 48 hours of infection. Proper care reduces the risk of complications like pneumonia, which can be life-threatening. Therefore, getting vaccinated annually is crucial for effective prevention.

The primary flu vaccine is called the Quadrivalent influenza vaccine (split virion, inactivated), marketed as Fluarix Tetra.

It contains antigens for four strains of influenza viruses:

• A/Michigan/45/2015 (H1N1)pdm09-like strain
• A/Hong Kong/4801/2014 (H3N2)-like strain
• B/Brisbane/60/2008-like strain
• B/Phuket/3073/2013-like strain

Each 0.5 ml dose provides 15 micrograms of hemagglutinin of each virus strain, aimed at preventing infections caused by these four viruses.

This vaccine works by activating the immune system to produce antibodies targeting the hemagglutinin proteins on the viral surface. These antibodies help neutralize and prevent the influenza viruses. It's recommended to receive the vaccine annually, typically before the start of the flu season in October. It is suitable for individuals aged 3 years and older, with revaccination advised for children between 3 and 9 years if they haven't been previously vaccinated.

Common side effects include soreness at the injection site, fatigue, muscle pain, and mild fever. Less common reactions may involve dizziness, rash, or swelling. The vaccine is delivered via intramuscular injection into the deltoid or thigh muscles, ensuring safe administration without intravenous injection to prevent severe allergic responses.