What is influenza?

Influenza (flu) is an acute respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. People who have flu often feel some or all of these symptoms: runny or stuffy nose, cough, sore throat, fever, headache, fatigue (tiredness), and muscle or body aches.

Anyone can get sick with flu, even healthy people. Serious complications related to flu, such as pneumonia, encephalitis, and myocarditis, can happen to anyone at any age. These complications can be life-threatening and result in death. Getting an influenza vaccine is the best way to prevent flu and its complications.

What is influenza vaccine?

There are 2 different types of inactivated influenza vaccine available in Thailand which are:

1. Trivalent inactivated influenza vaccine containing 3 strains of the influenza virus
2. Quadrivalent inactivated influenza vaccine containing 4 strains of the influenza viruses

Influenza viruses are always changing. Each year, World Health Organization (WHO) makes the recommendation for the influenza vaccine composition to match circulating influenza viruses in that year.

After vaccination, it takes about 2 weeks for antibodies to develop in the body and provide protection against influenza virus infection. The influenza vaccine offers protection against the flu for about 1 year. Therefore, most individuals should get the influenza vaccine once a year.

There’s still a chance you might get flu after having the influenza vaccine. However, the vaccine can reduce the severity of your symptoms and lower the risk of having serious illness from the flu and needing to stay in the hospital.

 

Who should get the influenza vaccine?

Everyone 6 months of age and older should get the influenza vaccine annually. Vaccination is especially important for people at high risk of flu complications, including:

1. Pregnant women (second and third trimesters)
2. ​Children 6 months to 2 years old
3. People who have chronic illnesses, such as chronic obstructive pulmonary disease (COPD), asthma, heart disease, kidney disease, and diabetes
4. Adults 65 years and older
5. People with neurodevelopmental disabilities
6. People with weakened immune system due to disease (such as people with HIV or AIDS) or medications (such as those receiving chemotherapy or radiation treatment for cancer)
7. People who are obese with a body mass index (BMI) of 35 or higher

When you should get the influenza vaccine?

The best time to get vaccinated is in the early rainy season (May) or the early winter (October), before influenza viruses begin spreading in your community. However, vaccination throughout the year is still beneficial.

How important of the influenza vaccine during COVID-19 pandemic?

Because flu and COVID-19 have many symptoms in common, it can be hard to diagnose which condition you have based on your symptoms alone, and it is possible to have flu and COVID-19 at the same time. Flu and COVID-19 coinfections may worsen the symptoms and increase the risk of serious complications and death.

Influenza vaccine is especially important during COVID-19 pandemic because it could reduce the symptoms that might be confused with those caused by COVID-19, apart from preventing the flu and reducing the severity of flu illness and hospitalizations.

If you want to get the influenza vaccine and a COVID-19 vaccine, you can get both vaccines at the same time.