Weidman Burke, Chelsea. "Vaccination." Gale Health and Wellness Online Collection, Gale, 2020.
Vaccines protect you (and everyone around you) from highly infectious and potentially deadly pathogens (disease-causing organisms such as bacteria and viruses) without you needing to be exposed to the actual pathogen.
Vaccines allow your body to produce infection-fighting cells and pathogen-specific antibodies, which are the molecules that remain in your immune system and recognize and attack pathogens. A vaccine mimics an infection by exposing your immune system to a weakened or dead pathogen, allowing the system to "see" this pathogen and build up protection against it (without you actually being exposed to the infectious pathogen and getting sick). Then, if you are exposed to the real pathogen, you are protected, or at least much less likely to acquire that particular disease and experience complications from it.
It takes up to two weeks for you to be fully protected after getting a vaccine because it takes that long for pathogen-specific antibodies to be produced. If you are exposed to a pathogen before or right after getting the vaccine for it, you may get sick simply because your immune system hasn't had time to produce enough antibodies.
You may have minor symptoms after getting a vaccine, such as aches and fever, that feel like you're getting sick, but you aren't (vaccines almost never cause the illness they aim to protect you from). The symptoms you feel are your immune system responding to the vaccine and producing protection against the pathogen.
Vaccination not only protects yourself, it also protects everyone around you. If enough people get vaccinated (between 75–94% of the population, depending on the disease), it will likely protect those who don't get vaccinated. When enough people are vaccinated against the disease, a pathogen has a hard time being passed from person to person and can't spread easily through a community.
Herd immunity is especially important to those who can't get vaccinated because they are too young, too old, too sick, or have an allergy or chronic condition that prevents them from receiving a specific vaccine. It can even protect the few people who have been vaccinated but didn't have a strong immune response to them, leaving them vulnerable to disease.
Protecting yourself and your community aren't the only reasons to vaccinate. As more people in a region vaccinate, the diseases they protect against become rarer; in fact, if the vast majority of people immunize for long enough, diseases can be eradicated from their region. Smallpox, for example, was eradicated worldwide.
On the flip side, if we stop vaccinating, we make ourselves and our communities much more vulnerable to diseases and epidemics.
Like any medicine, vaccines can cause side effects, but they are usually mild (low-grade fever, sore throat, soreness around the injection site) and go away a few days after getting vaccinated. However, there is an extremely small chance you could have a more serious rare side effect, such as a severe allergic reaction, other serious injury, or death.
There is a one in a million chance of having a serious reaction to a vaccine, according to the Centers for Disease Control and Prevention (CDC). The risks and complications associated with many of the serious diseases that vaccines protect against have much higher odds of causing problems if you were to get sick with them.
Aside from being sick with a potentially serious illness, not vaccinating can also increase the risk of you spreading disease to people around you. This is especially troubling if they are at a higher risk of complications due to age or other health conditions.
Outbreaks can happen when people hesitate or refuse to vaccinate themselves or their kids (usually called being "vaccine hesitant" or "anti-vax"). When an entire community has low enough vaccination rates, outbreaks can occur because the pathogen can circulate, spreading from person to person. The World Health Organization declared the anti-vaccine movement as one of the top ten threats to global human health in 2019.
Developing a vaccine against a pathogen depends on multiple factors, such as if it is a bacteria or virus, what part of it is infectious, and how the immune system responds to it. Therefore, there are many different kinds of vaccines:
Live, attenuated: Contain live but weakened pathogens that don't cause serious disease in healthy people. These vaccines are extremely effective because they resemble infection with the live, full-strength pathogen, so they produce a robust immune response. However, because these vaccines contain live (though attenuated) pathogens, not everyone can receive them.
Inactivated: Contain killed pathogens that produce immune responses without the risk of causing disease. Multiple doses are usually needed to build up or maintain protection.
Subunit: Contain parts of the pathogens (called subunits) that the immune system can recognize and use to build protection against the entire pathogen. Side effects are less common because the entire pathogen is not present. People with weakened immune systems can receive these vaccines, but boosters are commonly needed to maintain protection.
Recombinant: Contain genetically engineered cells that express parts of the target pathogen that trigger the immune system to recognize and build protection against it. Side effects are less common because the entire pathogen is not present. People with weakened immune systems can receive these vaccines, but boosters are commonly needed to maintain protection.
Conjugate: Combine a weak pathogen with a stronger one so that the immune system can recognize the weaker one, which wouldn't, on its own, provoke an immune response.
Toxoid: Contains weakened bacterial toxins (called toxoids) that train the body to fight off the normal toxin without causing illness.
There are vaccines for over 20 different bacteria and viruses, with some vaccines having multiple different types, formulations, and dosing schedules. To help organize when you should get which vaccine, the CDC publishes vaccine schedules for children and adults.
The children and adolescent (from birth to 18 years old) vaccine schedule can be found here: https://www.cdc.gov/vaccines/schedules/hcp/imz/child-adolescent.html
The adult (18 years and older) vaccine schedule can be found here: https://www.cdc.gov/vaccines/schedules/hcp/imz/adult.html
In general, the majority of routine vaccines are recommended to infants between birth and 18 months because their immune systems are still forming and encountering new bacteria and viruses. The ideal situation is to have a child be vaccinated before they come in contact with the bacteria or virus so they are protected once they do encounter the pathogen.
Some vaccines require multiple doses to achieve the best protection possible due to a variety of factors, including the type of vaccine it is (inactivated vaccines, for example), not enough antibodies being produced after the first dose to successfully fight off an infection, or protection wearing off over time.
A few vaccines need to be regularly administered throughout adulthood to maintain protection, such as the annual flu shot or the tetanus shot booster every 10 years. The specific flu viruses that are most prevalent in a season tend to change from year to year, which is why you need to get a new flu shot each year. Two vaccines, the shingles and pneumococcal shots, are recommended for people aged 65 and older because they are at a greater risk of both shingles and pneumococcal infections. And some vaccines are only recommended if you are traveling to certain parts of the world where the diseases they protect against are common, such as yellow fever or typhoid.
The anti-vaccination (anti-vax) viewpoint advocates for rejecting vaccinations against diseases. An anti-vax individual may choose not to receive one vaccine or may refuse all vaccinations. An anti-vax parent may also choose not to vaccinate their child. The related term "vaccine hesitancy" describes a person who is reluctant to administer vaccines, but is willing to consider the benefits and risks and may ultimately decide to vaccinate. The World Health Organization (WHO) identified vaccine resistance or hesitancy as one of the top ten threats to global health in 2019. Vaccines currently prevent an estimated 3 million deaths worldwide per year, according to the WHO, mostly among children. If vaccination becomes universally accepted, WHO estimates an additional 1.5 million deaths could be prevented annually.
The History of Vaccines is an award-winning informational, educational website created by the College of Physicians of Philadelphia, one of the oldest medical societies in the United States.
“The majority of parents who reject [vaccination] requirements today, however, aren't from vulnerable groups. They're opting out for their own religious or personal beliefs."
Emily Atkin is a staff writer at the New Republic.
In the following viewpoint, Atkin argues that states should allow fewer exemptions to childhood vaccination requirements. According to Atkin, parents are increasingly seeking exemptions to vaccination against potentially fatal childhood diseases for personal or religious reasons. This practice, the author argues, poses a danger to vulnerable children who cannot be vaccinated for medical reasons or have compromised immune systems. Atkin contends that the federal government is unlikely to enact legislation that mandates vaccination for a variety of reasons. The author asserts, therefore, that individual states are best positioned to curb childhood disease outbreaks by limiting vaccination exemptions.
Source: "Academy of American Family Physicians, http://www.aafp.org. Disclaimer: This information is not a tool for self-diagnosis or a substitute for professional care. This image may be used for personal, non-commercial purposes only.
"US Public Opinion Regarding Childhood Vaccinations, 2008 and 2018." Gale Opposing Viewpoints Online Collection, Gale, 2019, www.gale.com.