As per the World Health Organisation, every year 3 to 5 million people get infected with severe influenza throughout the world. Influenza, also known as the flu, is one of the most common respiratory infections seen in people. It usually presents with fever, cough, muscle pain, runny nose, sore throat and headache, all of which can last for up to two weeks. While in most cases, flu patients recover on their own, sometimes it can turn into a severe life-threatening condition. But a simple flu shot can prevent it all.
What are flu shots?
A flu shot, also known as the influenza shot, is a flu vaccine which protects against three or four strains of influenza virus. There are four different types of influenza virus; A, B, C and D, but out of these, the infection caused by influenza A and B can result in serious illness. Flu shots are given on a yearly basis to prevent viral infection.
There is a trivalent influenza vaccine, which is given to the people to protect them from two subtypes of influenza A and one subtype of influenza B. However, a quadrivalent vaccine protects you from two types of influenza B virus.
What are there two different types of influenza vaccines?
There are two different types of influenza vaccines; the live attenuated vaccine and the inactivated vaccine. The live attenuated vaccine contains a weakened form of the influenza vaccine which is given to people above the age of 6 years. The inactivated vaccine contains an inactivated form of the influenza virus which does not cause infection but can generate immunity. The live attenuated vaccine is given as a single dose nasal spray to healthy people within the age group of 2 to 49 years, while the inactivated vaccine is given via injection in two doses at least 4 weeks apart.
Flu shots may provide protection against SARS-CoV-2 virus
There have been various studies which have shown that flu shots can help in providing protection against the novel coronavirus, SARS-CoV-2.
In a large study done on 92,000 patients in Brazil, it was found that an inactivated trivalent flu shot can not only protect you from getting severe COVID-19 but can also reduce the risk of mortality by 20% when taken before the onset of COVID-19 and 27% when taken after the onset of COVID-19 symptoms.
Another study conducted in Italy showed that a quadrivalent flu vaccine can improve the immune response which makes it quickly recognise and kill any harmful organisms that would be invading the lungs.
A study conducted on the elderly population in the US showed that the people who did not get the flu shots were at risk of persistent viral infections which reduce the T-cell diversity, thus lowering their immune strength.
All these studies indicate that flu shots can help the immune system fight off COVID-19 infection effectively.
For more information, read our article on Flu (Influenza).
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