Allergies, and Diseases, and Vaccines, Oh My!
If you’re a human, like me, I’m sure you’ve sneezed at least once in your lifetime. While sneezing is a normal, semi-autonomous bodily function that your body uses to expel things that irritate your nasal mucous membrane, it can sometimes mean that there’s something else going on. This something else could be a few different things such as a viral infection, a bacterial infection, or pollen. Bodily infections are obviously harmful but what about pollen? Pollen seems pretty harmless, right? Despite this, many people suffer from allergies, with pollen being a common allergen.
Allergies probably aren’t a foreign concept to you. Many people, myself included, have suffered or suffer from allergies, whether it be to pollen, gluten, or anything else. But why exactly do allergies happen? One person’s body might not react to pollen at all, yet another person experiences itchy eyes and goes into a sneezing fit whenever they smell a flower. The answer has to do with the immune system. An allergic reaction occurs when your immune system mistakes something harmless for a harmful pathogen, thus it mounts an immune response against the perceived threat.
This begins when a type of white blood cell in your body called a T cell responds to a new, foreign antigen (the allergen) and thinks it’s dangerous. It then interacts with another type of white blood cell called a B cell. The B cell can create and secrete antibodies which will then circulate in the blood and bind to a specific receptor on the outside of other immune cells called basophils and mast cells. These immune cells are now able to cause an acute inflammatory response which results in the typical allergic reactions, such as sneezing, or getting rashes.
So you now know a bit more about allergies. However, other threatening agents are out there, like the aforementioned viruses and bacteria. I say agents rather than organism because viruses aren’t considered living organisms by many. They’re small infectious particles of proteins and nucleic acids that infect the cells of living organisms and use them to replicate themselves. When the viruses aren’t inside a host cell they are called virions and they are sometimes covered by an envelope of lipids.
Several illnesses such as the flu are caused by viruses. The flu, or influenza, has many symptoms such as a runny nose, sore throat, a fever, headaches, muscle pains and more. Influenza is an airborne disease and can also be spread by touching surfaces that have been contaminated with the virus and then putting your hands in your mouth or on your eyes. That’s why it’s important to always wash your hands, especially during flu season.
There are antiviral drugs that help treat influenza, such as oseltamivir, but vaccination can prevent viral infections and is usually recommended for a lot of other viruses such as Hepatitis. Vaccination works by administering a weakened or nonfunctional version of a pathogen into the body. The body then mounts an immune response and is able to memorize the disease due to adaptive immunity. Adaptive immunity is basically how your body remembers a disease that it encountered in the past so that it’ll be able to quickly eliminate that disease if it is ever encountered again in the future. Vaccinations are the reason why diseases like polio are very rare nowadays. However, it is important to note that sometimes multiple vaccines may be necessary as the disease could rapidly evolve, thus your body will no longer be able to recognize it. Rapidly evolving diseases are difficult to become immune to.
Asides from influenza, an even more common viral disease is the common cold. Although you’re probably familiar with the common cold, you may not know that there are actually over two hundred different viral strains that can cause the common cold, with the most common strains being rhinoviruses. The common cold is also airborne and can be spread the same way as influenza. You can reduce your chances of getting the disease by washing your hands, just like with influenza. Unfortunately though, it’s difficult to vaccinate against the common cold because it mutates rapidly, but also because of all the different viral strains that are involved with this disease.
You’ve learned a little about viral diseases, but not all diseases are caused by viruses. Some are a result of microscopic organisms called bacteria. Bacteria are single celled creatures that are found virtually everywhere on Earth, including the human body! Although bacteria can cause disease, some of them are very beneficial to us. There are bacteria in our gastrointestinal (GI) tract that help with digestion and can create vitamins that we need to stay healthy. They even help to prevent dangerous bacteria from infecting the GI tract.
There are relatively few pathogenic bacterial species, but a well-known one is the streptococcus bacteria that causes strep throat. There are different ways of treating bacterial infections such as using nonsteroidal anti-inflammatory drugs (NSAIDs), or antibiotics. Although antibiotics have been a common treatment for many years, we’re currently faced with a serious problem involving their use.
Just like how we humans can gain immunity to certain diseases, bacteria are able to gain immunity to antibiotics, although through different means. There are a number of causes for bacteria evolving to become resistant to antibiotics. A big reason is because of the increase in antibiotics being prescribed and people not finishing their antibiotics or missing doses because the symptoms of the disease have lessened or disappeared. Another reason is that antibiotics being unnecessarily prescribed, such as to treat a viral infection even though antibiotics are completely useless against viruses.
The most important takeaway from this is to always finish your antibiotic regimen, even if you think you no longer need it. Hopefully in the near future we’ll discover a way to reverse bacterial resistance, but for now the best thing you can do is to try to remain healthy! Regular exercise, a good diet, and of course, remember to wash your hands!