Immune System Versus the Flu

According to the statistics on the CDC website, every year about 8% (with a range of 3% to 11% ) of the U.S. population would get sick with the flu and become symptomatic, and if including those whom might be asymptomatic, the range would become 5% to 20%.[1,2,3] It is estimated that an average of 31.4 million Americans would visit the doctor’s office because of the flu and about 200,000 would be hospitalized per year.[2,3] The flu is very pricy and estimates a cost of around $10 billion per year of direct medical cost as well as an additional $15-16 billion a year in the opportunity cost of lost earnings.[3] Once an individual becomes exposed and infected, it takes an average of 2 days (with a range of 1-4 days) for the symptoms to show up.[1,2] The contagious period of the flu has a wide range and can begin even before symptoms develop while lasting up to 5 to 7 days after becoming sick; the most contagious period is around the first 3 to 4 days after becoming sick.[1] The age population at the greatest risk of complications are those over the age of 65, with an estimated 70%-85% of total flu-related deaths occurring in this age group.[1,2,3]

            The immune system is a complex network of different types of cells and organs which work together to rid the body of foreign invaders such as bacteria and viruses from wreaking havoc in the body.[4,5] The primary components of the immune system include white blood cells (WBC), antibodies, lymphatic system, spleen, bone marrow, and the thymus.[4] You can consider WBCs to be the police officers of the body in that they patrol for threats such as viruses and bacteria, then they perform an immune attack that destroys these foreign invaders.[4] Antibodies are like the “wanted posters” that can identify these foreign invaders, they mark these threats for destruction. The lymphatic system is a delicate tubular network that is connected throughout the body. Some of its functions include responding to bacterial and viral threats, managing body fluid levels, absorbing fats from the GI tract as well as ridding the body of cellular wastes that could otherwise bring harm to the body.[4] Next, we have the spleen which basically just acts as a filtration system for blood by removing any microbes as well as any outdated and impaired red blood cells (RBC).[4] The bone marrow produces WBCs, RBCs as well as the platelets that are used to help clot any wounds. The thymus takes in the progenitor cells that come from the bone marrow and helps them to mature into T-lymphocytes.[4] Overall, the immune system works together to prevent any pathogens from damaging our body.

            Now that we have a basic understanding of the immune system, let’s talk about how we get the flu and how our body reacts. To illustrate, think your coworker Bob and you are going to the office for work in the same elevator. Bob (the source) is sick with the flu and sneezes. The germs (invaders) leave Bob and travels everywhere in the air, including to you (the new host) when you breathe in the contaminated air. Now in this situation, whether you get sick or not depends on the quality of your immune system as well as the number of invaders that came out of Bob’s sneeze which ends up going into your body. In addition to boosting your immune system, there are other ways to reduce the number of invaders that get side your body such as by washing your hands before touching any of your body’s open entry ports (eyes, nose, mouth, etc.) as well as keeping a reasonable distance from those who are sick. Many miseries that arise from the flu comes from your body’s immune system trying to get rid of the invader. For example, the body raises its temperature to try to eliminate the infection, hence, a fever develops.[1,6] The body also produce interferons which can obstruct viruses from reproducing.[6] In addition, the body can instruct the immune system to send antibodies and WBCs to target the invaders and eventually eliminate them.[6] In addition to fever, many with the flu will also develop a cough, sore throat, runny/stuffy nose, body aches, headaches, and lethargy; however, it is important to keep in mind that not everyone with flu will get these symptoms.[1] 

            From the above paragraphs, we can see that the immune system is very essential to the survival of human beings. By keeping our immune system in tiptop condition, we are able to reduce our susceptibility to pathogen attacks and getting sick. The two simple ways of keeping the body and immune system healthy are eating a balanced diet and keeping an active lifestyle. You must have heard of the saying “an apple a day keeps the doctor away” before. This is not saying you never will get sick if you eat an apple a day (otherwise all hospitals and pharmacies would be out of business), but instead, it is implying that if your diet is well balanced with nutrients, vitamins, minerals, and antioxidants, you will decrease your susceptibility to becoming sick.[8] In addition to a balanced diet, exercising regularly helps to keep the body in good shape; however, you should not exercise as much when you are feeling sick because your body needs rest in order to recover from an illness.[4,7] Some other things to help keep your immune system strong include not smoking, preserving a healthy weight, getting sufficient sleep each day, washing hands frequently, making sure meats are cooked properly, and also reducing stress.[7] Last but not least, you may also want to speak with your doctor regarding getting a flu shot each year to minimize your risk of getting the flu.

Lastly, this article is not meant to treat, diagnose, or prevent any disease; it is for informational purposes only so make sure to consult with your physician and pharmacist before starting any new medications, medical food, or supplements.


[1] “Key Facts About Influenza (Flu).” Centers for Disease Control and Prevention, 13 Sept. 2019,

[2] “Flu Statistics: What Are Your Odds of Getting the Flu?” Edited by Carmelita Swiner, WebMD, 28 Aug. 2020,

[3] Thomas, Jen. “Facts and Statistics About the Flu.” Healthline, Healthline Media, 19 Nov. 2018,

[4] Khatri, Minesh. “Use Your Immune System to Prevent the Flu (but Get the Vaccine, Too).” WebMD, 30 Aug. 2019,

[5] Department of Health & Human Services. “Immune System.” Better Health Channel, Department of Health & Human Services, 30 Mar. 2014,

[6] Drexler, Madeline. “How Infection Works.” National Center for Biotechnology Information, U.S. National Library of Medicine, 2010,

[7] Publishing, Harvard Health. “How to Boost Your Immune System.” Harvard Health, Sept. 2014,

[8] Team, Heart and Vascular. “3 Vitamins That Can Help Boost Your Immunity.” Health Essentials from Cleveland Clinic, 2 Jan. 2020,

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