The flu, a deceivingly simple and well-known virus recently took the world by a storm. This year’s flu season impacted more than 34 million Americans, surpassing the Swine Flu pandemic and the past decade of the flu season . The vicious attack of the virus lead to the highest hospitalization rates in years and became fatal for 53 children . At this point, one might ask, how could something so microscopic, common, and well-researched lead to such horrifying ramifications and statistics?
The flu, a general term for the influenza virus, is one of the most versatile and multifaceted viruses. The remarkably quick evolution of new traits from the eight total genes that the virus has (compared to humans that have 20,000) is at the core of what makes the flu so dangerous . Influenza, when inside one’s body, infiltrates the immune system and sets up its own factory production of viral cells. The first step in this process is picking the lock of the cell membrane to access the host cell. To accomplish this, influenza has specific proteins of various shapes called antigens on its membrane, which allows it to carefully bind to the receptors of the cell membrane. The virus then travels to the nucleus in order to take control of the DNA center. At this point, it deceives the nucleus into producing more viral cells instead of normal cells. Once enough are made, the army of viral cells burst out of the host cell and carry on their mission to infect other healthy cells . This invasive process is influenza’s modus operandi: hijack normal cells, mass produce viral cells, infect normal cells and repeat.
The molecular explanation of how the flu attacks the body is a stepping stone in understanding how the virus is able to evolve every single year. The main form of evolution is called antigenic drift. In this, antigens, the proteins on the membrane of the virus, go through mutations in shape, size and form which causes a very different response in our immune system no matter how minor the change is . Because of that, old antibodies from previous encounters with the flu virus are ineffective in curing the illness and are unable to recognize the virus because of its complete transformation .
Antigenic drift is the reason a new flu vaccine is needed every single season. Over 140 influenza centers across 113 countries constantly collect data on how the virus is mutating and which strains of the flu are making the most people sick . The World Health Organization (WHO), then, tracks trends in the molecular and epidemiological data in order to create a vaccine that they believe will be the most effective in combating the flu . Most of the time their prediction is accurate; however, other times, like this year, they miss the target virus.
When the flu virus enters the body through airborne water droplets associated with sneezing, coughing and talking, it can lead to the common symptoms. Society tends to label the peak of these symptoms as “flu season”. Although the exact timing of flu season is hard to predict, there is always certainty that it will be in the winter months . Many have questioned why that might be. Researchers have not come to a definite conclusion but have proposed three possible theories:
- People spend more time indoors in the winter with the windows closed. This makes people breathe more of the same air as others which can lead to sickness.
- The lack of the sun and Vitamin D in the winter weakens people’s immune system; thus, making them more susceptible to the virus.
- The flu virus thrives in the cold and dry air of the winter and dies out in the hot humid air of the summer.
Most of these theories are difficult to study in a laboratory setting. But in 2007 when scientist Peter Palese discovered that guinea pig can receive and transfer the flu like humans, he was able to set up an experiment to test the last theory . He compared the infection rate of the animals at 41 degrees, 68 degrees and 86 degrees. He found that at the coldest temperature all of the pigs got infected but at the hottest temperature, none of the pigs got infected. This indicates that in colder temperatures, the virus is better able to travel in the water droplets in the air which leads to higher infection rates.
Having background knowledge to better understand how the flu works and why it is so dangerous, allows a closer look at this years flu mishaps which led to such a significant negative impact. This year, the death toll associated with the flu exceeded all expectations. On its own, the flu isn’t deadly but can lead to complications and death for at-risk populations including people over 65 years old, children and people with underlying illness . These are the populations that commonly have weaker immune systems and may not be able to effectively fight off the influenza virus. In fact, children under the age of five have a lack of immunological experience because of their developing system; thus, the flu shot doesn’t protect them and their body overreacts to something as common as the flu .
The most common complications with the flu include pneumonia, sepsis and heart attack . Sepsis, one of the most fatal complications, occurs when a person’s defensive responses to the flu virus becomes overwhelmed and starts attacking healthy cells . This can lead to a whole host of symptoms in which a person’s body goes into shock and then ultimately shuts down.
The core reason this year’s flu season was so much worse than the past is because of the lack of effectiveness of the vaccine. When making the vaccine, scientists tested its effects against various strains of the virus in chicken eggs  . Researchers found it successful in combating influenza in chickens and assumed it would work in humans. It did not. This years H3N2 strain of the influenza virus mutated into an altered form when it entered the human body, thus making the vaccine unsuccessful for that strain  .
Millions of people have gotten sick from the flu and the best (only) line of defense is a vaccine that does not always work and medication to reduce the symptoms. Given the history and pervasiveness of the sickness, one would assume that as a society we would have come up with a better treatment plan than what is in place now. This year’s unfortunate damage of the flu has revealed some shortcomings in our medical system. First off, there needs to be a better way to test the strains of influenza when making a vaccine. Using chicken eggs to predict if the vaccine will be successful in all humans seems outdated. Secondly, better education about the symptomology and effects of the flu virus can help people identify their symptoms better and thus get the care they need faster. This is the most important for new mothers, the elderly and people with underlying illness. With the information presented here, hopefully more people understand how influenza can hijack the body and how difficult it can be to combat such a rapidly changing virus. Only through the spread of knowledge can people better prevent illnesses such as the flu.
Edited by: Anhthi Luong
Illustrated by: Eugenia Yoh