It's that time of the year again: Flu Season. October is when the flu vaccine becomes available to the public. Along with advocating vaccination to the public, comes opponents protesting their credibility. So here I shall discuss what the flu vaccine is, the main argument against vaccination, and why there is a consensus advocating for vaccination.

What is the flu and why does the vaccine change every year?

According to the Centers for Disease Control and Protection, the flu (influenza) is a respiratory illness caused by influenza viruses. Symptoms include fever, chills, sweats, headache, sore throat, nasal congestion, fatigue, muscle aches, and a dry cough. There are two main types of viruses: Type A and Type B. Both have sub-types, are responsible for seasonal flu outbreaks, and both are subject to change. Two ways the virus can change is by antigenic drift and antigenic shift. Antigenic drift can occur in Type A and more slowly in Type B. It is described as when small changes in the viral genes occur and accumulate overtime leading to the body's immune system not being able to recognize them anymore; thus, developing sickness again. Antigenic shift occurs only in Type A and is when two different flu strains infect the same cell and mix. This can allow the virus to move from animals to humans.

How do the vaccines work?

A vaccine consists of parts of a pathogen that are either killed or weakened. Once the vaccine is introduced to your body, your immune system will develop antibodies against it, kill it, and remember it so that the next time the pathogen arises, your body will mount a faster attack on it.

What is the main reason some are against vaccination?

In 2001, the Institute of Medicine (IOM) gathered a committee to review whether there was a relationship between use of thimerosal in vaccines and neurodevelopmental disorders. Thimerosal is a mercury containing organic compound and a preservative. A preservative is a compound that prevents the growth of microbes. Preservatives are used in vaccines to decrease the possibility of micro-organisms spreading, which can happen in multi-dose vials. The 2001 review concluded that there was insufficient evidence to support whether or not there was a relationship between neurodevelopmental disorders and the use of thimerosal. In 2004, the IOM conducted another review to determine whether there was a relationship between autism and thimerosal use in vaccines. The review concluded that the evidence favored rejection of the idea that there is a relationship between thimerosal use in vaccines and the development of autism. Despite this evidence, opponents of vaccination contend that the use of thimerosal in vaccines can cause autism. To limit the exposure of mercury to children, childhood flu vaccines were created without thimerosal, yet autism rates continued to increase. If thimerosal caused autism, we would expect to see the opposite of this.

Why should you get the flu shot?

The flu vaccination can help prevent you from getting sick from the flu— which is the purpose of it. Between 1976 and 2007, 80-90 percent of flu related deaths occurred in people aged 65 years or older. In a 2016 study, people 50 year old or older who got their flu vaccine reduced their risk of getting hospitalized by the flu by 57 percent. Thus, it can reduce your risk of hospitalization if you get the flu and make your illness milder if you get sick. Most importantly, vaccination can help protect the people around you — especially the vulnerable such as children and older adults.

So go out and get your flu shot. You'll not only be protecting yourself but your loved ones.