Flu vaccinations – effectiveness, indications and contraindications

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The effectiveness of flu vaccination is an issue that puzzles everyone who plans to include this vaccine in their vaccination schedule. Every year there are studies on the effectiveness of influenza vaccination and the rates are consistently going up. What should you know about the flu vaccine and to what extent will it protect you against getting sick?

Basic information about the flu

Flu is an acute infectious disease caused by the flu virus. It is spread by droplets such as when sneezing. The greatest number of cases of influenza is recorded during seasonal epidemics. The influenza virus comes in three varieties. These are:

1. influenza virus type A – occurs in humans and animals;
2. influenza type B virus – occurs only in humans;
3. influenza C virus – occurs in humans and pigs.

The flu may be mild, but there are often cases that result in numerous complications and even death. The most common symptoms of flu are:

1. high fever – it can even reach 39-40 degrees Celsius. It usually reaches its peak on the first day of the disease. The temperature usually drops slightly on the 3-5th day of illness. If high fever persists, it is a sign of post-influenza complications, including pneumonia or bacterial superinfection;
2. chills – they accompany the increase in temperature and last for the first days of the disease;
3. pain in muscles and joints – initially the so-called breaking in the bones, and then the pain becomes quite intense;
4. headaches – most often occurring at the very beginning of the disease and characterized by high intensity. They are accompanied by eye pain, photophobia and drowsiness;
5. dry cough and sore throat – the cough is persistent and tiring, turning into a wet cough as the disease progresses. A sore throat is not typical of flu, it is a symptom of dry cough;
6. feeling exhausted – lasts from the onset of the disease and may last up to 3 weeks;
7. lack of appetite – this is your body’s natural reaction to the flu virus. It relieves the body of the digestive system for the benefit of the immune system.

For more information on flu, see Flu

Characteristics of the flu vaccine

The flu vaccine is given seasonally, which means you have to have a new dose of the vaccine every year. This is because new flu viruses emerge every year, and the previous vaccine would not immunize the body against it.

Influenza vaccines that are available in Poland belong to the category of non-live vaccines. This means that they contain only a small part of the virus in the composition. There are two types of flu vaccines available in Poland.

The first is Influvac Tetra. This vaccine is inactivated and contains influenza virus surface antigens of 4 strains, multiplied in chicken embryos. It provides active immunization against 4 strains of influenza virus and is therefore referred to as quadrivalent.

The second vaccine is Vaxigrip Tetra. Like Influvac, it is a quadrivalent vaccine. The flu vaccine has the lowest number of recorded adverse vaccine reactions. The current strains used to make flu vaccines are recommended by the World Health Organization.

You can read about the safety of flu vaccines here: Are flu vaccines safe

Flu vaccine – indications and contraindications

The flu vaccine is recommended for anyone who does not want to deal with the symptoms of flu, and also wants to avoid its unpleasant complications. Nevertheless, the vaccine is especially indicated for certain groups in society. People should get vaccinated against flu:

1. all persons aged 50 and over;
2. residents of nursing homes or round-the-clock care, children and adults staying in other long-term medical care facilities;
3. children and adults struggling with chronic heart disease, e.g. coronary heart disease or heart failure;
4. children and adults struggling with chronic lung disease, e.g. asthma or chronic bronchitis;
5. children and adults diagnosed with chronic kidney, liver, blood, nervous system disease or immunodeficiency;
6. people suffering from diabetes;
7. pregnant women or those planning to become pregnant during the next flu season;
8. medical staff;
9. medical students who undergo training in contact with sick people.

Although the flu vaccine is recommended, it cannot be given to everyone without exception. The contraindications for giving the flu vaccine are:

1. anaphylactic hypersensitivity to egg white or vaccine antibiotics;
2. acute illnesses with fever;
3. acute diseases of moderate or severe course;
4. Guillain-Barré syndrome, which has been diagnosed within six weeks of previous influenza vaccination;

Particular care should be taken in people with impaired immune systems, as the body’s response to vaccination may be impaired. Contraindication to flu vaccination is also taking corticosteroids, cytotoxic drugs or radiotherapy.

What should I know about immunization? Check: Vaccinations in questions and answers

Vaccination effectiveness – What does the flu vaccine protect against?

The job of the flu vaccine is to prepare the immune system for the flu viruses that will cause the disease in a given season. Influenza virus is distinguished from other viruses by high variability, therefore every year the vaccine is adjusted to the dominant strains.

The main purpose of the vaccine is to protect you from catching the flu. However, if it happens that, despite the vaccine, the patient becomes ill anyway, the vaccination makes the course of the vaccine much milder. Having the flu vaccine also minimizes the risk of side effects and complications.

How can flu be prevented? Check: Is immunization the only way to prevent flu?

Flu vaccination effectiveness

There is currently no vaccine in the world that is 100% effective. In the case of the flu vaccine, its effectiveness depends on many factors. In some years, the flu vaccine was 50% effective. In 2019, the actual effectiveness of the flu vaccine was 47%.

It should be noted that the most important factor that determines the effectiveness of the vaccine is the adjustment of the formulation to the currently dominant influenza virus. Unfortunately, the hallmark of the flu virus is that it mutates very quickly, so the vaccine has to be updated every year. The effectiveness of the vaccine also depends on the health of the vaccinated patient. It’s no secret that the effectiveness increases with the healthier and younger the patient. It can therefore be concluded that the influenza vaccine provides moderate protection against the virus.

It is worth noting that vaccinating people over the age of 65 in the event of falling ill reduces the risk of death by almost 50%.

What is worth knowing about compulsory vaccinations? Take a look: Mandatory vaccinations – everything you need to know

Before use, read the leaflet, which contains indications, contraindications, data on side effects and dosage as well as information on the use of the medicinal product, or consult your doctor or pharmacist, as each drug used improperly is a threat to your life or health.