How Do Vaccines Produce Protection?
Posted: May 26th, 2021 at 07:06PM
Vaccines are the best way to prevent diseases that are dangerous and even deadly. They help reduce the risk of infections by using the body's natural defenses and strengthening the immune system against certain illnesses. Even more, some vaccines can create lifelong immunity to minimize the chances of acquiring and spreading the diseases, thus limiting potential complications and future cases.
While vaccines are widely known for their benefits to one's health, many are still skeptical because of how they're perceived to work in the human body. Really, this boils down to a lack of understanding of how vaccines work.
To shed light, let's explore how the body fights illnesses and how vaccines work to protect people.
How the Body Fights Illnesses
When bacteria and viruses infect the body, they attack and multiply, causing an illness. The immune system uses natural bodily defenses, carried in the white blood cells or immune cells, to fight off the infection.
White blood cells have three essential components. First, the macrophages swallow and digest the germs and dying cells, leaving behind small parts (called antigens). Next, the B-lymphocytes create antibodies to attack the antigens. Finally, the T-lymphocytes fight the cells that have been infected and immediately get to work if the same germ enters the body again.
During the initial infection, it takes a few days for the body to use all these natural germ-fighting tools. As a result, should there be a future exposure, the immune system learns how to protect the body against that particular disease.
How Vaccines Work to Produce Protection
The human immune system is made up of antibodies that fight infections naturally. In effect, you gain immunity against the disease by either catching the illness or through vaccination.
Vaccines contain a modified version of the disease-causing germ, either inactivated, killed, or weakened, to get the protein or nucleic acid. Once administered, commonly through injection, the body responds to the vaccines as if it is a full-fledged germ. In effect, your body is trained to recognize these as foreign elements and create memory cells and antibodies to protect you from getting future infections.
Similarly, the vaccines work by imitating the infection, causing your system to produce T-lymphocytes and antibodies. In general, this type of infection does not lead to illnesses. However, there is a potential to experience minor symptoms (such as fever or body pains) as the body builds immunity. This is fairly normal and nothing to be worried about.
Essentially, vaccines expose the body to the inactivated, killed, or weakened illness-causing germ so that your immune system understands how to fight it. Once the imitation infection leaves your body, it leaves the memory cells to automatically remember how to fight the diseases should you encounter the real germs in the future.
The Types of Vaccines (and What they Mean)
Scientists and medical experts have different ways of developing vaccines based on the information they have about the virus or bacteria. This determines how the germs will actually infect the cells and how the human immune system will respond to it.
Experts also make practical considerations when it comes to making vaccines. Particularly for global infections, it's vital to take note of environmental conditions, geographical differences, and vaccine delivery to determine its effectiveness.
To date, two of the most common types of vaccines are called live and inactivated.
According to the CDC, "Live, attenuated vaccines fight viruses and bacteria. These vaccines contain a version of the living virus or bacteria that have been weakened so that it does not cause serious disease in people with healthy immune systems. Because live, attenuated vaccines are the closest thing to a natural infection, they are good teachers for the immune system."
The most known live vaccines are for measles, mumps, rubella (MMR Combined); chickenpox; yellow fever; cholera; and typhoid.
On the other hand, inactivated vaccines are made by inactivating or killing the germ to fight off the bacteria and viruses. This type of vaccine produces immune responses different from live, attenuated vaccines, and will often require multiple doses to build or maintain immunity, also known as booster shots. Keep reading for more on this!
An Important Note About Vaccination
For most vaccines, the first dose does not provide complete immunity. As such, it's essential that more than one dose is completed to build immunity.
Similarly, for other vaccines, immunity wears off after a while and a "booster" dose is needed to bring back the immunity levels. Booster shots are often administered a few years after the initial dose. For example, a vaccine against diphtheria, tetanus, and pertussis is initially administered to infants to build immunity. Booster shots are then administered to kids aged 4-6, and another one for pre-teens around 11-12 years old.
In addition, many live vaccines need more than one dose to develop the best possible immune response. The MMR vaccine is known for this, wherein a second dose helps ensure that you have sufficient antibodies to counter the infection.
Lastly, some vaccines (like that against flu) need a yearly dose for adults and children over six months of age. The annual flu vaccine is vital to be effective because flu viruses causing the disease can change every season. Likewise, immunity can wear off over time. That's why getting the flu vaccine each year helps keep you protected even if the viruses don't change.
The Key Takeaway
Many people believe that natural infections – which could potentially lead to herd immunity – are better than getting vaccinated. Unfortunately, doing this leads to severe complications and worsened health conditions.
On the other hand, receiving vaccines is the safest and most effective way to protect yourself and your family, people who can't get vaccinated for health reasons, and the community at large. While it may cause side effects, just like any medication, vaccines help prevent and eliminate diseases. Essentially, you're getting protection now and for future generations, too.