Flu Season is Coming — Are You Protected?

Due to the unpredictable weather conditions, we are seeing more frequent outbreaks of influenza. Many people still mistakenly believe that the flu only occurs during the rainy season, but influenza can spread throughout the year and affect all age groups, not just young children or those with weak immune systems. Even healthy individuals can catch the flu virus and spread it to others. The best way to prevent the flu is to get the flu vaccine.

What is Influenza (Flu)?

Influenza (Flu) is caused by the influenza virus that infects the upper respiratory tract, leading to symptoms like fever, cough, runny nose, nasal congestion, sneezing, body aches, and fatigue, similar to the common cold, but the symptoms are usually more severe. Additionally, the flu can lead to complications such as bronchitis and pneumonia. It may also exacerbate pre-existing health conditions such as heart disease, diabetes, and liver or kidney diseases.

Since everyone is at risk of contracting influenza, the World Health Organization (WHO) recommends preventive measures, including getting the flu vaccine for both children and adults, particularly for the elderly.

What is the Influenza Vaccine?

The influenza vaccine is an injection vaccine made from inactivated viruses. It is produced through a safe manufacturing process and highly effective in preventing influenza. Although individuals who receive the vaccine can still contract the flu, but their symptoms will be milder. The flu vaccine does not protect against the common cold caused by other viruses.

The Quadrivalent Influenza Vaccine

Since the first isolation of the influenza virus in 1993, there has been continuous development of vaccines to protect against the flu. In 2012, the World Health Organization (WHO) recommended adding a B strain of the virus to the vaccine to enhance its effectiveness. This led to the development of the Quadrivalent Influenza Vaccine, which covers four strains of the virus:

• Influenza A/H1N1
• Influenza A/H3N2
• Influenza B Victoria lineage
• Influenza B Yamagata lineage

The WHO recommends the quadrivalent vaccine because it provides broader protection against influenza, covering more strains than the previous versions.

Who "Should" Get the Influenza Vaccine?

• Patients with chronic diseases, including diabetes, stroke, kidney failure, asthma, chronic obstructive pulmonary disease (COPD), heart disease, and cancer patients undergoing chemotherapy.
• Pregnant women who are at least 4 months pregnant.
• Individuals aged 65 years and older.
• Young children aged 6 months to 2 years.
• Individuals with intellectual disabilities who are unable to care for themselves.
• Patients with thalassemia.
• Those with immune deficiencies and individuals living with HIV.

Especially those with pre-existing health issues should receive the influenza vaccine annually for protection.

Who "Should Not" Get the Influenza Vaccine?

• Infants younger than 6 months.
• Individuals with a history of severe allergy to chicken or eggs, as the vaccine is produced using chicken eggs.
• Individuals who have had a severe allergic reaction to a previous influenza vaccine.
• Individuals with a fever or acute illness.
• Patients with uncontrolled underlying conditions or flare-ups should postpone vaccination until their condition stabilizes.

What are the Benefits of the Quadrivalent Influenza Vaccine?

In addition to protecting the body from all four strains of the influenza virus, the influenza vaccine offers additional benefits as follows:

• Provides broader protection against type B influenza virus strains.
• Reduces the incidence of influenza outbreaks.
• Decreases complications from influenza infections, especially in young children and individuals with chronic conditions.
• Reduces the use of antibiotics due to bacterial infections as secondary complications.
• Lowers treatment costs.
• Reduces absenteeism from work or school.
• Decreases hospitalization rates.
• Lowers the mortality rate from influenza.

Side Effects of the Influenza Vaccine

The influenza vaccine can cause such as redness and swelling at the injection area, fever, and muscle aches, which usually appear shortly after the injection. These symptoms will recover within 1-2 days. Severe allergic reactions are very rare. If they occur, symptoms may appear within 2-3 minutes to 2-3 hours after the injection and may include difficulty breathing, hoarseness, wheezing, hives, pale skin, fatigue, heart palpitation, or dizziness.

Source: Vaccine Information for the Public, Department of Disease Control, Ministry of Public Health.