By Kathryn Wolff
Campus student health leader
Flu season is the perfect time to delve into the history, science and importance behind vaccines.
In 1796, Dr. Edward Jenner created the world’s first successful vaccine for smallpox by inoculating an 8-year-old boy with matter from a human smallpox sore. The idea of immunization began to spread within medical research, and many years later, in 1885, Louis Pasteur created a 13-injection course, post-exposure vaccine for rabies.
Vaccines have come a long way since, and they have proven themselves to be the most cost-effective approach to the task of reducing childhood disease.
Groundbreaking vaccines developed in the 1970s, such as the measles, mumps and rubella (MMR) shot, are still used in America. With the development and rise in vaccination rates the U.S., diseases such as smallpox can be completely eradicated, thanks to the vaccine providing immunity.
In recent years, the U.S. has been experiencing a lull in immunization rates. In the 2024-2025 school year, kindergarten students averaged a 92.5% coverage via the MMR vaccine. While this number seems high, it is imperative to the proper workings of the vaccine and the phenomenon of herd immunity for the rate to be at least 95%.
Herd immunity is the basis for almost all vaccines. It relies on the idea that if 95% or more of a population is vaccinated for a disease, they can prevent the spread of an illness. This, in turn, increases public health and can help populations who are immune-compromised or immune-suppressed to not encounter vaccine-preventable diseases.
The flu shot is a great, easy way to prevent the spread and lessen the symptoms of an illness.
This vaccine is slightly different from others mentioned because the flu has many mutating strains. Researchers must collect data that will help them indicate which flu strain will be most prevalent this flu season.
Starting in the 2024-2025 flu season, all flu vaccines were developed to be trivalent vaccines, meaning they protect against three different influenza viruses.
The 2025-2026 season will include two influenza A viruses and an influenza B/Victoria virus. Once the shot is given through the arm and enters a patient’s bloodstream, the immune system can activate and respond accordingly.
When the inactivated virus enters the body, antigen-presenting cells, such as dendritic cells, will alert the immune system of detected viral proteins. The dendritic cells will bring parts of the proteins to the lymph nodes and present their findings on the cell’s surface using MHC molecules.
After detection, the body will initiate a rapid response called innate immunity, a kind of immunity made up of cells such as macrophages and natural killer cells. These cells responding to viral proteins cause a release of cytokines and chemokines in the body. It is why flu shots can cause soreness and some mild flulike symptoms.
After the innate response kicks in, the adaptive response works in the background to build antibodies.
Dendritic cells show the T helper cells of the adaptive response and subsequently activate the B cells that will begin to produce antibodies to combat the inactivated flu virus in the body. The body then keeps these antibodies as a memory response, and cells, such as memory B cells and cytotoxic T cells, remain ready in case they come into contact with the real flu virus.
To better support public and personal health this flu season, get vaccinated to help your body build its defenses!
An easy way to get the flu shot or other vaccinations is through the GCU campus health center, which serves on-campus students, commuters, faculty and staff .You can walk into the clinic for a vaccine or use the student portal to make an appointment. For more information, contact the health center or reach out through Instagram @gcucampushealth.
Vaccines are a vital form of preventative medicine that have advanced rapidly. Using an inactivated virus in the shots helps the body build memory and defend against diseases.
Vaccinations are available to all GCU students, faculty and staff through the health center this flu season!
References
Centers for Disease Control and Prevention. (2024, September 17). Key facts about seasonal flu vaccine. https://www.cdc.gov/flu/vaccines/keyfacts.html
Khan, M. (2025, August 20). Across the U.S., childhood vaccination rates continue to decline. International Vaccine Access Center. https://publichealth.jhu.edu/ivac/2025/across-the-us-childhood-vaccination-rates-continue-to-decline
Nandi, A., & Shet, A. (2020). Why vaccines matter: understanding the broader health, economic, and child development benefits of routine vaccination. Human vaccines & immunotherapeutics, 16(8), 1900–1904. https://doi.org/10.1080/21645515.2019.1708669
World Health Organization. (2025). A brief history of vaccination. https://www.who.int/news-room/spotlight/history-of-vaccination/a-brief-history-of-vaccination
