Why are flu vaccines important?


What is flu?

Flu, also known as influenza is a seasonal respiratory infection, caused by influenza viruses, which are present year-round. These viruses cause fever, dry cough and associated symptoms, which while easily treatable, can sometimes lead to severe conditions and even death.

What are the types of seasonal influenza viruses?

According to WHO, there are not one, but four different types of influenza virus of concern, each of which has a different propensity of causing the disease.

  • Influenza A viruses are the most common and are categorized on the basis of two proteins on the surface of the virus; hemagglutinin(HA) and neuraminidase(NA). The bird flu of 2009, was an influenza A virus, H1N1.
  • Influenza B viruses are categorized on the basis of lineages and the most common are B/Yamagata and B/Victoria.
  • Influenza C viruses cause mild infection and aren’t of much concern.
  • Influenza D viruses affect only cattle and not humans.

What are the symptoms commonly associated with influenza?

Once the viral load increases sufficiently in the body after infection, seasonal influenza shows symptoms such as:

  • Fever
  • Dry cough
  • Muscle pain
  • Malaise
  • Runny nose
  • Sore throat

Which groups are at a higher risk of seasonal influenza?

While every person is susceptible to influenza, groups that have underdeveloped or decreasing immune systems are at further risk. They include children below 5 years, pregnant women, the elderly, people with chronic respiratory conditions, and individuals on immunosuppressive medicines.

What are the serious consequences of influenza?

Normally, influenza symptoms subside on their own without any serious medical intervention. But cases where the people are at a higher risk, do not resolve the symptoms easily and require hospitalization and in severe cases even cause death. In developed countries, the elderly( >65 years) are the group where most deaths associated with influenza occur.

How is flu transmitted and how to prevent its transmission?

Influenza virus is an airborne virus, so it travels via droplets often expelled during coughing or sneezing. In order to prevent transmission, it is advisable to cover the mouth and nose to prevent inhalation of airborne droplets and frequent washing of hands and sanitisation of surfaces.

Where does the role of the vaccine come?

While treatment for flu is mainly symptomatic, prevention is a better method to protect oneself against seasonal disease. This is where vaccines come into play. A flu vaccine or flu shot as it is commonly called is a formulation that primes the immune system against the body to fight against the infection.

How does the flu vaccine work?

As mentioned above, vaccines prime the immune system. The formulation contains a weakened form of the influenza virus, which is enough to elicit an immune response yet doesn’t cause infection. What happens here is that the weakened virus gets recognized by the immune system and antibodies are generated against the virus, and memory against the virus is also generated to protect against further infections. So, after vaccination, if the person comes in contact with the virus, there is a serious chance that the person will develop symptoms, and even if the symptoms do develop, they do not require any medical intervention. The flu vaccine takes around 10-14 days to develop an immune response after administration.

Do the vaccines need to be taken only once in a lifetime?

No, these vaccines are seasonal and need to be taken annually, i.e., once a year. The reason for the same is attributed to the fact that the influenza virus tends to develop new strains against which previous vaccines may not prove to be as effective.

Are the vaccines safe to take?

Yes, the vaccines are safe to take with mild side effects like a sore arm, slightly raised temperature, and muscle aches, nothing different from other vaccines. Usually, paracetamol resolves the issues.

Dr. Mohit Singh Tandon is a competent consultant physician, guiding you right in case of cold or flu. Visit Dr. Tandon’s Evexia for the right advice and treatment. Book your appointment with us!

Contact us at:

Sai Baba Mandir, D block -129, Saket, New Delhi, Delhi 110017

+91-7835856540, +91-9737381110


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