Flu vaccination is a protective method that creates immunity in the body against the virus that causes flu disease.

What is flu?

Seasonal influenza is a contagious illness that occurs most frequently from late autumn to early spring. It is an infection caused by the influenza virus.

What are the symptoms of flu?

Flu symptoms usually appear 1 to 3 days after the virus enters the body. Common symptoms include:

• High fever and chills
• dry cough
• Sore throat
• Runny and stuffy nose
• Widespread joint pain throughout the body along with headache
• Severe weakness

Symptoms such as diarrhea and vomiting may be more common in children. Infants may experience symptoms such as loss of appetite, irritability, and drowsiness.

Flu symptoms typically last about a week and are most severe in the first few days. However, recovery can take up to two weeks.

How is flu transmitted?

Flu is a respiratory illness. People with the disease can transmit the virus through droplets expelled from their mouths and noses when they cough, sneeze, or talk. The influenza virus contained in these droplets can enter the respiratory tracts of people within close proximity (usually 1-2 meters), posing a risk of infection. If a person's immune system is not strong enough to fight off the virus, they may become infected with the flu.

People with the flu can spread the virus to those around them for 1 day before and 5 days after symptoms appear.

Crowded spaces, schools, and elderly care facilities are risky areas where the flu virus can spread easily. To prevent the spread of infectious diseases in these areas, it's important to maintain hygiene and minimize close contact with sick people.

How is flu diagnosed and treated?

During seasonal epidemics, the flu can usually be diagnosed based on the patient's signs, symptoms, and physical examination. In most cases, additional testing is not necessary. However, in some cases, doctors may use specialized tests to confirm a flu diagnosis. The most sensitive test method is generally the PCR (polymerase chain reaction) test. This test aids in diagnosis by detecting genetic material of the influenza virus in patient samples. The presence of genetic material from the influenza virus indicates a positive test.

The primary approach to flu treatment is supportive care. Rest and drinking plenty of fluids are recommended. These measures are generally sufficient for mild cases, and the illness typically resolves within a few days.

However, antiviral medications may be used in individuals with severe infection or those at risk of complications. Antiviral medications such as oseltamivir, zanamivir, and peramivir can shorten recovery time and reduce the risk of serious complications. These medications should be used as soon as possible after the onset of flu symptoms and should only be taken under medical supervision.

What are the complications caused by flu?

While the flu is generally a mild illness, it can sometimes cause serious complications. Complications from the flu include:

• Lung infections: The influenza virus can infect the lungs, causing infections such as pneumonia. This can cause serious respiratory problems, especially in people with weakened immune systems or chronic illnesses.
• Sinusitis and ear infections: The flu can cause sinus and ear infections. These conditions often present with pain and discomfort.
• Organ inflammation and failure: The flu can cause inflammation in organs such as the heart, brain, and muscles. These conditions can lead to multiple organ failure and lead to serious health problems.
• Excessive inflammatory response and sepsis: The influenza virus can trigger an excessive inflammatory response in the body. This can lead to a potentially fatal condition called sepsis.

These complications are more common in people with weakened immune systems, the elderly, young children, and those with chronic illnesses. Therefore, it's important to consult a healthcare professional if flu symptoms become severe or if you are in a high-risk group.

What is the flu vaccine?

The flu vaccine is a vaccine that uses specific antigenic fragments of the flu virus to stimulate the individual's immune system to react to the virus. This vaccine creates immunity against the flu virus, helping to reduce the severity of the illness and minimize the risk of complications.

Particularly at-risk groups, including the elderly, those with chronic illnesses, those with weakened immune systems, and healthcare workers, are recommended for the flu vaccine. The flu vaccine is typically administered before flu season, ensuring a person's immune system is better prepared to face the virus.

Flu vaccination is an effective way to prevent or make illness milder. It reduces the risk of complications by creating immunity against the flu virus and can help reduce the severity of the illness.

Should you get a flu shot every year?

Yes, it's recommended to get the flu vaccine every year. The influenza virus is constantly changing, and different variants can emerge each year due to mutations in its surface proteins. This can cause the immune system to encounter different antigens each time and fail to develop a sufficient memory.

Therefore, each year, the World Health Organization (WHO) identifies the most common types of influenza viruses and makes recommendations for vaccine production. These vaccines protect against the most common types of influenza viruses for that season.

The flu vaccine should be boosted at the beginning of each flu season, regardless of whether you've had the flu before or have received it in previous years. The vaccine's effectiveness can last between 6 and 8 months, and protection begins approximately two weeks after vaccination. The best time to get the flu vaccine is during October and November, the months when the flu virus is most prevalent seasonally, but vaccination can continue until the end of March. Therefore, getting the flu vaccine every year is an important step in protecting yourself from the disease.

What are the benefits of the flu vaccine?

The flu vaccine has many benefits:

• Reduces the risk of flu: The flu vaccine reduces the risk of contracting the flu. The vaccine prepares the body to fight infection and strengthens the immune system, providing protection against illness.
• Reduces hospitalizations: Flu vaccination can reduce hospitalizations due to flu in all age groups. It can reduce the risk of flu-related complications and severity of illness, especially in individuals with chronic conditions (such as diabetes, COPD, and heart disease).
• Provides protection during pregnancy: The flu vaccine during pregnancy protects expectant mothers from respiratory infections, thus reducing the risk of hospitalization during pregnancy. It can also protect the baby from the flu in the first months after birth.
• May reduce illness severity: Even in people who get the flu despite having received the flu vaccine, it can reduce the severity of the illness. The vaccine can also shorten the course of the illness and reduce the risk of complications.

These benefits of the flu vaccine prevent the spread of disease throughout the community while also providing positive health benefits. Therefore, vaccination of at-risk groups is particularly important.

Can I get sick even though I have had the flu vaccine?

Yes, getting a flu shot may not prevent the disease completely, and in some cases, people can still get sick with the flu. This can happen for a few reasons:

• Immunity development process: It takes approximately two weeks for the body to develop immunity after receiving the flu vaccine. If you come into contact with the virus during or after vaccination, your immune system may not have yet developed sufficient protection, and you may still be at risk of illness.
• Influenza virus subtypes in the vaccine: The flu vaccine generally protects against the most common and predominant influenza virus subtypes. However, the vaccine may only protect against certain influenza virus subtypes. If someone comes into contact with a different influenza virus subtype not included in the vaccine or that emerges independently of the vaccine, immunity may not be conferred, and the risk of illness may remain.
• Immunocompromised: The elderly, those with chronic illnesses, or individuals with weakened immune systems may not mount a sufficient immune response despite vaccination. In these cases, they may still become ill if exposed to the flu virus, despite being vaccinated. However, the flu vaccine can mitigate the course of the illness and reduce the risk of complications in these individuals.

The flu vaccine is generally recommended to reduce the severity of illness and minimize the risk of complications. Therefore, even for individuals who are still susceptible to the flu despite vaccination, getting the flu vaccine is important to mitigate the effects of the illness.

Who should get a flu vaccine?

Getting the flu vaccine is especially important for certain risk groups. The following people should get the flu vaccine:

• Children: Children over 6 months of age who are not allergic to the vaccine can receive the flu vaccine. Flu can cause serious complications in children, so vaccination is important.
• Elderly: Elderly people are more susceptible to the flu and its complications due to their weakened immune systems. Flu vaccination can reduce the severity of illness in older adults.
• People with chronic illnesses: Those with chronic illnesses such as heart disease, COPD, and diabetes should get the flu vaccine. These individuals are at risk of complications from the flu.
• Pregnant women: The flu vaccine is important for protecting both mother and baby during pregnancy. Women who are not pregnant during the first trimester can receive the flu vaccine.
• Healthcare workers: Healthcare workers should be vaccinated because they may come into contact with the flu virus frequently. This is important both to protect their own health and to reduce the risk of transmission to their patients.
• Those without allergies : Those who do not have a serious allergy to the vaccine content can get the flu vaccine.

The flu vaccine may provide indirect protection against coronavirus ( COVID-19 ) because it can reduce the risks that flu poses to other respiratory infections, such as COVID-19 . Flu, a disease that weakens the lungs, can make you vulnerable to other infections, such as COVID-19 . Therefore, getting a flu vaccine can strengthen your overall immune system and increase your resistance to infections other than coronavirus.

What are the side effects of the flu vaccine?

The flu vaccine is generally well tolerated, but some people may experience mild side effects. Most of these side effects are mild and temporary. Some common flu vaccine side effects include:

• Swelling and pain at the vaccination site: Mild swelling, pain, or redness may occur at the site where the flu shot was given. This usually resolves on its own within a few days.
• Systemic effects: Some people may experience mild systemic effects after a flu shot, such as fatigue, headache, muscle aches, low-grade fever, and tiredness. These effects are considered part of the body's normal response to the vaccine. They usually resolve on their own within a few days.
• Rare cases: In rare cases, allergic reactions may occur due to the flu vaccine. While these are very rare, serious allergic reactions, such as anaphylaxis, can occur in rare cases.

Note: Because the flu vaccine is an inactivated vaccine, it cannot cause influenza in humans. Vaccinated individuals often get the flu not because of the vaccine itself, but because they have come into contact with the virus after vaccination or have developed other viral infections after vaccination.

Side effects are generally mild and short-lived, and the benefits of the flu vaccine in preventing illness and reducing its severity generally outweigh the side effects.