how long does the flu shot last, it’s importance and work function

how long does the flu shot last, it’s importance and work function

The term “flu” is generally used to represent the influenza virus infection. It is a contagious respiratory infection that is harmful for the throat and the lungs. It can be mild (like the common cold) or severe. That is why it is really important to take the flu shot. If you are wondering how long does the flu shot last, continue reading to know about it’s work function and importance. 

how long does the flu shot last?

Since the flu mutates every year, you’ll need a yearly vaccine that has been adjusted to protect you against the most recent strain. But if you want to know how long does the flu shot last right after you get it, the answer is six to eight months. The flu vaccine protects you for the entire year.  You can get a flu vaccination to protect yourself from the seasonal flu viruses that are now circulating. 

Both seasonal infections (i.e flu) can prompt issues by tainting the respiratory framework. While most people might have to take a few days off and recover in bed, certain individuals require hospitalisation and specific treatment to recuperate.

So, how long does the flu shot last? Well, it depends for different kinds of shots. Some of them are- 

  • The BCG vaccination against tuberculosis is permanent and never needs to be renewed.
  • Vaccinations against polio, tetanus, and diphtheria endure for ten years.
  • If the booster shot is administered six months to a year after the initial dose, protection from hepatitis A will extend for ten years.
  • If treated for more than six months, hepatitis B lasts for five years.
  • Meningitis Vaccines are effective for three to five years that are given for A and C type. 
  • When you get a rabies vaccination, you are safe for three to five years.  
  • The three-year shelf life of typhoid vaccine.
  • Ten years are given by the yellow fever vaccine.

Importance of flu shot 

Now that you know how long does the flu shot last, let’s check out the importance of getting the flu shot every year. The flu vaccination primarily offers individual protection from influenza. The flu shot induces the immune system to create antibodies that are tailored to the influenza virus types it contains. Those who have received the vaccine are less likely to develop problems, need hospitalisation, or experience long-term health effects from influenza infections.

Getting vaccinated is also essential for halting the flu’s spread among populations. Even those who may not be at a high risk for illness themselves might serve as carriers, unintentionally spreading the virus to people who could be more vulnerable to serious illness. By getting vaccinated against the flu, people help build “herd immunity” or “community immunity.” As a result, the flu vaccination serves as a shield, easing the overall burden of the illness and potentially negative effects on public health.

The capacity of the flu shot to lessen the burden on healthcare systems is a crucial component of the vaccine’s significance. Healthcare practitioners can more effectively manage their resources and concentrate on treating other medical disorders by lowering the number of flu cases through universal immunisation.

In order to distinguish flu symptoms from those of other respiratory infections, such as COVID-19, the flu vaccination acts as a prophylactic strategy. While you are looking for how long does the flu shot last, you must know that by receiving a flu shot, you can lessen the risk of having the illness and more easily recognize the signs of COVID-19.

How does it work 

Besides knowing how long does the flu shot last and it’s importance, you must be aware of how it works. 

1.Antigen Identification

Determining the antigenic elements of the influenza viruses is the first stage in creating the flu vaccine. Antigens are the foreign chemicals that cause the body’s immune system to react. The strains of influenza that are now circulating that are most likely to result in disease during the upcoming flu season are identified by scientists. The strains chosen for the vaccination are then chosen. 

2.Vaccine Production

Following the identification of the antigenic strains, vaccine production starts. There are two common ways to make the flu shot: egg-based or cell-based. The chosen influenza viruses are cultured in chicken eggs, collected, and then purified to generate the vaccine using the egg-based technique. The viruses are grown in animal cells, such as mammalian or insect cells, in the cell-based approach.

3.Immune System Activation

A flu shot involves injecting the vaccine into the patient’s body, which activates their immune system. The flu cannot be contracted through the vaccine’s inactivated or weakened influenza viruses. Once within the body, these viruses are recognized as foreign by the immune system, which then triggers an immunological reaction

4.Antibody creation

The flu immunisation induces an immunological reaction that outcomes in the formation of specific antibodies that are coordinated against the flu strains contained in the antibody. It is recommended to get inoculated before the beginning of influenza season on the grounds that the age of antibodies takes time, normally half a month.

5.Memory Cell Formation

The immune system creates memory cells in addition to manufacturing antibodies. These cells “remember” the precise antigens exposed during vaccination, enabling a quicker and more effective immune response. Memory cells support longer-lasting immunity and offer defence past the current flu season.

6.Prevention of Infection

This shot’s safe response brings about the creation of antibodies that go about as protection against the flu infections contained in the immunisation. While getting an influenza inoculation may not totally keep you from a wide range of flu, it diminishes the risk of disease.


This shall clear your doubts on how long does the flu shot last and it’s importance. It creates herd immunity which makes it tougher for the virus to spread throughout the community. For instance, if six people who have all received the flu shot enter a room with one infected person, there is very little likelihood that any of them would contract the illness, meaning the virus has nowhere to go.