Transcription
The Arabic translation is working. Antibiotics. Antivirals. Vaccines. Have you ever wondered what they do or how they work? One thing to understand is that they can greatly aid in the function of your immune system. Your immune system is amazing. We are being very general here because this is not a video specifically about the immune system. But it is important to understand some basics of the immune system to understand the amazing function of antibiotics, antivirals, and vaccines. Your immune system is designed to protect you from pathogens. Pathogens can be all sorts of things. Certain types of bacteria. Viruses. Infectious protozoa, yes, unfortunately there are some dangerous types of protozoa. Certain types of fungi. Parasitic worms. All of these can be pathogens. Your skin is actually part of your first line of defense in protecting you from pathogens, not only as a barrier, but also, there are beneficial microbes that live on your skin and can keep the numbers of bad microbes down. Mucous membranes are also part of the first line of defense. But pathogens sometimes get in, and when they do, you have more lines of defense to protect you. For example, your second line of defense includes non-specific white blood cells like macrophages. These cells are incredible. They actually engulf pathogens and these participate in an amazing response called the inflammatory response, which could have a whole video on it. Then you have a third line of defense. Unlike the first two lines of defense, the third line of defense is more of a specific defense because it can target specific pathogens. Examples of immune cells involved in this specific response include white blood cells known as lymphocytes. T lymphocytes or T cells and B lymphocytes or B cells. T cells and B cells are very specific to interact with antigens. Antigens are molecules that can be found on pathogens. Although we should note that antigens can be anything foreign in your body. For example, someone with a pollen allergy might react to pollen antigens. An antigen can trigger a response from a T cell or a B cell. And again, this video does not go into the amazing types of immune responses with these cells, which we encourage you to explore. We want to mention a very important piece of information before we continue. There are memory B and T cells. This is extremely important because these cells can "remember" a pathogen. Memory B and T cells remain in the body. If the pathogen returns, these cells can multiply and fight the pathogen quickly and effectively. We will explain why this is especially important when we get to vaccines. So let's return to antibiotics, antiviral drugs, and vaccines. How do they participate in all of this... What do they do... How do they work? Let's start with antibiotics. Antibiotics target one type of pathogen: bacteria. Now while not all bacteria are bad—in fact, many bacteria play many beneficial roles in both our bodies and our environment—infectious types of bacteria can be a problem. They are the bacteria that cause strep throat, staph infections, some types of pneumonia, and urinary tract infections. And while your immune system does go after these bacteria, it can sometimes use a little help. And that's where antibiotics come in. Antibiotics can destroy bacteria in a number of ways... they can damage bacterial cell walls or block the production of important proteins that bacteria might need. A doctor can prescribe antibiotics in pill form, but they can also be injected or delivered in an IV. Now the word antibiotic can be broken down where you see the word "anti" which can mean against and "biotic" which can mean life. And this is really helpful because you don't want to confuse it with two other words. These, unfortunately, sound very similar. One of these words is antigen, as we mentioned earlier, which is a molecule that can be found on a pathogen. Antibodies are proteins made by certain immune cells, like B cells, which can be used to help fight pathogens. They often have a Y-shaped letter. Some antibodies attach to pathogens making the pathogen unable to function properly. But antibodies can also be used to tag pathogens so that they can be "eaten" by macrophages. Now, we mentioned that immune cells can have a type of memory when they encounter a pathogen. This can include the ability to produce antibodies against pathogens that immune cells have encountered before. And that's where vaccines come in. Vaccines are a way to expose your body to an inactive or weakened form of a pathogen. One form of the pathogen—because it is inactive or weakened, it actually prevents you from developing the disease from the vaccination itself. However, your body still mounts an immune response. By mounting an immune response, which includes producing antibodies against the pathogen, your immune system will "remember" the pathogen. And in this way, if your body at any time encounters a real, active pathogen—your body will already be familiar with it and therefore we say your body is already immune to the pathogen. This can lead to your body being able to mount an attack on the real thing more quickly and effectively. Vaccines can be effective against different types of bacteria and viruses. We take the amazing work of vaccines for granted in preventing devastating bacterial and viral diseases from developing in people. But thanks to vaccines, some terrible bacterial and viral diseases have been eradicated in some areas, but it is important for them to continue to prevent some of these diseases from reemerging. There is also something else really important that you should know about vaccines. Some people may not be able to receive certain vaccinations—from someone who has a severely compromised immune system because they might have some kind of illness—to a newborn baby who is not old enough to receive many vaccinations—to a pregnant mother. These vulnerable populations rely on what is known as "herd immunity"—meaning if others around them are vaccinated against certain pathogens, which may provide them a degree of protection against that pathogen because it cannot spread to them easily. So vaccinations not only provide protection for the person receiving them, but they also provide protection for others around them. For example, let's look at the infectious viral disease rubella. The rubella vaccine is typically given in early childhood. Rubella generally results in a rash along with some mild symptoms like a low-grade fever or sore throat. But if a pregnant woman contracts this virus, her unborn child may suffer from severe birth defects. But pregnant women are advised not to get the rubella vaccine during pregnancy so they can be considered a vulnerable population during this timeframe if they are not already immune to this virus. Herd immunity can be protective in an example like this. Learn more about "herd immunity" in some additional reading suggestions. And because there is so much misinformation about vaccines out there, especially in recent years, we have also included some additional reading suggestions about vaccines in general that you might want to check out. So as we discussed, vaccines can help our immune systems prepare for all sorts of pathogens, including bacteria and viruses. Remember, antibiotics are specific to bacteria only. But antivirals are designed to help target viruses. Antiviral drugs can come in many forms such as pills, liquids, or in the form of an IV. They can make viral infections less severe, although many of them must be given a specific time frame after contracting the virus to be effective. Many antiviral drugs work by affecting virus replication, which is difficult, because if you remember from our virus video, viruses replicate using our cell machinery. So an antiviral must be able to stop the virus without negatively impacting the cells. For example, if a virus has an important protein that the host cell uses to make—an antiviral can be designed to prevent the production of that protein—but it is important to check that the protein is not one that your cells use. One last thing. Pathogens can change. Mutate. In our natural selection video, we talk about how antibiotics may not be effective against certain types of bacteria due to antibiotic resistance that can occur. In our virus video, we mention how viruses can mutate. An example of this is the virus that causes influenza, also known as the flu. This virus changes frequently, so it is likely that a flu vaccine that works this year will not be effective against the most common flu virus next year. There are actually scientists working hard to predict what the most common flu virus will be each year, and the flu vaccine is designed to elicit an immune response against that specific type so that if you encounter it, you can have protection. This is why there is a different flu vaccine each year and sometimes the effectiveness can vary each year. With mutations occurring, this is also a challenge in developing antivirals. An antiviral designed to target a specific virus may not work on a mutated form. Scientists continue to research solutions to combat a constantly changing world of pathogens. Well, that's all for Amoeba Sisters, and we remind you to stay curious. Translation by Youssef Haider.