Vaccine Insights
Image 1. Picture of mRNA vaccine.
This image shows how the mRNA vaccine works by creating a protein through mRNA which contains the genetic code explaining how to destroy the pathogen.
When was the last time you visited the doctor for an annual check-up and received a vaccine? Most of us have experienced getting a shot and going about our day, perhaps with a sore arm. But have you ever stopped to think about what was injected into your body? While vaccines are widely known as a preventive measure against diseases like COVID-19 or Hepatitis A and B, there’s more to them than meets the eye.
Vaccine Basics
A vaccine is a biological substance that can help increase immunity to a disease-causing pathogen by containing a weak form of the disease-causing pathogen. Vaccines are typically administered via injection to make direct contact with the skin and during this process, a small amount of an inactive version of the pathogen is injected.
Once injected, the white blood cells in your body are alarmed, producing antibodies to fight against the pathogen, also known as the antigen. These antibodies are Y-shaped proteins made by our immune system. They bind to the pathogen allowing the body to build immunity. Thus, when the real pathogen attacks, the immune system is equipped to eliminate the disease.
Figure 1. How the vaccine works post injection.
Part 1.
The vaccine introduces a form of a pathogen into the immune system
Immune system recognizes these as foreign invaders
Immune cells respond by producing antibodies
These antibodies attack and eliminate the part of the pathogen released
Immune cells remember these foreign invaders
Part 2.
The body is exposed to the real virus
The immune cells will recognize the real pathogen
The immune system will rapidly produce antibodies in response
The vaccine essentially prepares the immune system to fight off the real pathogen
Types of Vaccines
Apart from the fundamentals on what a vaccine is, it’s important to know there are different types of vaccines and they each function differently in how they equip the immune system to eliminate the disease. Chances are you probably have received at least one of these types of vaccines, maybe more.
Live Attentuated
Live attenuated vaccines contain a weakened form of the pathogen. Because these vaccines mimic a natural infection, they stimulate the immune system to generate a strong and enduring response. Typically, one dose, and sometimes two, is enough to provide lifelong immunity against the infection.
Examples: MMR (measles, mumps, and rubella), Chickenpox, Yellow fever
Inactivated
In comparison to live attenuated vaccines, inactivated vaccines contain the dead form of the pathogen, making them less potent. As a result, one or two initial doses are needed, followed by periodic booster shots to maintain immunity. This is why doctors recommend getting the flu shot annually to stay protected during flu season.
Examples: Flu Shot, Hepatitis A, Rabies
Subunit
Subunit vaccinations contain a specific portion of the pathogen like a capsid or a protein. Within subunit there are many kinds:
Polysaccharide
Target an immune response towards bacteria wrapped in sugar.
Protein-Based
Target an immune response against the protein component of a virus
Conjugate
Target an immune response to a bacteria wrapped in sugar which is then attached to a protein.
Subunit vaccinations are specifically beneficial for immunocompromised patients as they only contain a certain part of the pathogen, which leads to less risk in comparison to a weakened version or a heat-killed form.
Example: Pneumococcal, Meningococcal, Hepatitis B, HIV
Toxoid
Toxoid vaccines contain a toxin produced by the pathogen, helping the immune system build protection by targeting the components responsible for causing disease. Because the vaccine focuses only on these disease-causing elements, multiple booster shots are necessary to maintain immunity—similar to inactivated vaccines. By receiving a booster every 10 years, toxin-mediated diseases can be effectively prevented.
Example: Tetanus
Viral Vector
Viral vector vaccines use a genetically modified version of a different virus to fight the target pathogen. These carrier viruses can include measles, influenza, or adenovirus. This type of vaccine often triggers a strong immune response with just one dose, eliminating the need for booster shots.
Example: Covid-19 (AstraZeneca)
The adenovirus serves as the vector for the AstraZeneca version of the Covid-19 injection.
mRNA
mRNA vaccines use messenger RNA to instruct cells to produce proteins that target and destroy the pathogen, triggering an immune response. Because they do not use any form of the virus (live, inactivated, or subunit), there is no risk of the vaccine causing the disease in the patient. Additionally, mRNA vaccines are cheaper and more efficient to produce.
Example: Covid-19 (Pfizer-BioNTech, Moderna)
Figure 1. Diagram of types of Vaccines.
This figure portrays a visual version of the different types of vaccines to provide a better understanding of how to distinguish between the different types.
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There are about 44,000 - 98,000 deaths each year in the United States from preventable infections. Many of these deaths result from lack of access to treatment whether it be due to affordability extremes or other external factors. One measure to prevent many of these deaths is by getting vaccinated for the diseases that you can. So where can you find these affordable vaccines?
Affordable Vaccine
Texas
Austin
Austin Public Health
Costco Pharmacy
Austin Diagnostic Clinic
Williamson County Health Department
Houston
Harris County Health Departmnet
City of Houston Health Departmnet
Hope Clinic
St. Theresa Catholic Church
Texas Children’s Mobile Clinic Services
Dallas
Dallas County Health and Human Services Immunization Clinics
Parkland’s Health Mobile Immunization Program
Martin Luther King Jr. Family Clinic
Los Barrios Unidos Community Clinic
College Station
Brazos County Health District
Beutel Health Center
BCS Health Clinic
Health 4 All
United States
Vaccines for Children
Vaccines for children are provided regardless of health insurance status at any Federally Qualified Community Health Center
State Specific Programs
Example: Shots for Tots and Teens (CO)
Federally Funded Health Centers
Vaccines.gov
Displays nearby health clincis with available vaccines based on zip code entered and income/budget specified
Sources
Buzzrx. “Where to Get Low-Cost Immunizations in the U.S.?” BuzzRx, 1 Sept. 2021, www.buzzrx.com/blog/where-to-get-low-cost-immunizations-in-the-us.
“How Do Vaccines Work?” World Health Organisation, World Health Organisation, 8 Dec. 2020, www.who.int/news-room/feature-stories/detail/how-do-vaccines-work.
Rodwin, Benjamin A., et al. “Rate of Preventable Mortality in Hospitalized Patients: A Systematic Review and Meta-Analysis.” Journal of General Internal Medicine, vol. 35, no. 7, 21 Jan. 2020, pp. 2099–2106, https://doi.org/10.1007/s11606-019-05592-5.
Sager, Jordan. “The Science behind Vaccines – How Do Flu and COVID-19 Vaccines Differ?” Franciscan Missionaries of Our Lady Health System, 18 Nov. 2021, health.fmolhs.org/body/covid-19/the-science-behind-vaccines-how-do-flu-and-covid-19-vaccines-differ/.
Thompson, Drew. “Team Led by Sun Receives X-Grant to Develop MRNA Vaccine Platform.” Tamu.edu, 2021, tees.tamu.edu/news/2021/07/team-led-by-sun-receives-x-grant-to-develop-mrna-vaccine-platform.html. Accessed 16 Dec. 2024.
U.S. Department of Health and Human Services. “Vaccine Types.” HHS.gov, 22 Dec. 2022, www.hhs.gov/immunization/basics/types/index.html.
Williams, Sarah. “How Do Vaccines Work?” Gladstone.org, 28 Apr. 2022, gladstone.org/news/how-do-vaccines-work.