Exploring Vaccine Development: The History and Future of the Vaccine
From early inoculation to modern mRNA technology, this week, we take a comprehensive look at the history and future of vaccines.
Table of Contents
Understanding Vaccination
Since 1796, much of vaccine manufacturing has changed, but the overall idea has stayed the same. The intention of a vaccination is to expose an individual to a safe dose of a virus or bacteria, prompting the body to create an immune response.
This small exposure allows our immune system to create antibodies, making it more likely that, if the body is infected with the bacteria or virus on a larger scale, the body will remember the virus and be able to quickly attack it.
This process involves various components of the immune system, such as the production of antibodies by B cells and the development of memory T cells that can recognize and fight off the specific pathogen in the future. Essentially, vaccines try to mimic the real infection on a much smaller scale as a preventative measure.
It is important to note that while vaccines are typically safe, some individuals who receive a vaccine may experience side effects, or experience symptoms of the illness the vaccine is trying to create protection from. However, vaccines undergo extensive testing and rigorous safety evaluations before being approved for use, and their safety continues to be monitored closely by health authorities.
While vaccines are critical to protecting yourself from harmful illnesses, they are also essential to protecting your community. When a large number of people in your community are vaccinated, this is called herd immunity. Essentially, this means that the disease you have been vaccinated for will have a much harder time spreading from person to person.
Although we have made incredible advancements in vaccination, it is a constantly growing field with new, innovative discoveries being made all of the time. In this article, we will explore some of the major advancements in vaccinology history, as well as dive deeper into what is in a vaccine, and different vaccine types.
Important Vaccine Developments Through History
Early Vaccination History
The practice of immunization predates the first modern vaccine. As early as the 15th century, individuals practiced variolation, exposing themselves to smallpox through variolation to prevent the disease. Variolation was the practice of introducing organic material of a person infected with smallpox, like scabs or pus, into the body of a healthy individual.
Then, as mentioned in the beginning of the article, English Physician Dr. Edward Jenner tested his hypothesis that infecting a healthy individual with cowpox would make them immune to smallpox in 1796. The success of this discovery is often referred to as the discovery of the first modern vaccination, and the name “vaccine” utilizes the latin word for cow, vacca.
The first laboratory-produced vaccine was not created until almost a century later, with Louis Pasteur's creation for fowl cholera in chickens in 1872. This was closely followed by his development of the post-exposure vaccination for rabies in 1885.
20th Century and Beyond
During the early 1900’s, the need for vaccinations became clear, as the population was being affected by deadly, fast-spreading diseases like the Spanish Flu. The first influenza vaccine was approved for civilian use in 1946, a year after it was approved for military use. Research for the influenza vaccine was led by Dr. Jonas Salk and Dr. Thomas Francis Jr. They would later go on to be critical in the discovery of the first polio vaccine, which was created from 1952-1955.
The late 20th century welcomed the invention of many new vaccinations, including ones for smallpox, hepatitis B, measles, whooping cough, and more.
One of the most successful uses of vaccination was witnessed in the 1990’s early 2000’s, where polio was eradicated entirely in the Americas. Other continents would soon follow with similar results. Although polio has not yet been eradicated worldwide, great progress has been made.
In the past few decades, there have been so many vaccine developments that it would be almost impossible to detail in one article. Notably, one of the greater developments includes new technologies such as mRNA. We will discuss mRNA, as well as its benefits and drawbacks, in the sections below.
Key Ingredients of a Vaccine
As discussed, vaccines work by exposing you to safe amounts of bacteria or viruses. However, their makeup includes more than just this singular component. Five key components you will find in most vaccines include antigens, diluents, adjuvants, preservatives, and stabilizers.
An antigen is a weakened or non-viable form of the bacteria or virus. This is what will train your immune system, allowing it to gain the ability to identify and protect against that specific disease. Diluents are a component of the vaccine used to dilute it to the desired concentration. This dilution is done right before administering the vaccine, and is usually a form of sterilized water or sterile saline.
Adjuvants are used in some vaccines to enhance the immune system's response to an antigen. They help to lower the concentration of a weakened or non-viable disease or virus a person needs to be exposed to. Preservatives are used to preserve the integrity of a vaccination by preventing it from fungal or bacterial contamination.
Vaccines need to be stored and moved after their creation in order to reach the people that need them. Stabilizers help to prevent the vaccine components from clumping, sticking to the vial, or undergoing chemical changes that could reduce their effectiveness during transportation.
The Creation of mRNA Vaccines and How They Differ
While mRNA vaccinations have been a topic of interest for decades, they became a major focus when the FDA fully approved the first mRNA vaccine, Pfizer’s COVID-19 vaccine, in 2021. This would quickly be followed by the approval for Moderna’s vaccine for the same disease in 2022.
So what makes an mRNA vaccine different from a traditional one? The biggest difference is that mRNA vaccines eliminate the need for part of the virus or side effect to be injected into an individual. Instead, they use messenger RNA (mRNA) to deliver instructions to our ribosomes within our cells. These instructions tell the ribosomes to produce a specific viral protein (antigen). Our immune system then recognizes this protein as foreign and triggers an immune response.
One major advantage of mRNA is that, once it has served its purpose, it is broken down by the body, which results in no permanent change to DNA. Following the promising results of utilizing mRNA in COVID-19 vaccines, there are now multiple mRNA vaccines in clinical trials.
For a more in-depth look at mRNA vaccines, how they work, and companies making strides in the field of mRNA vaccines, visit our previous articles “The Evolution and Impact of mRNA” and “Importance of Lipid Nanoparticles in mRNA”.
Vaccines Currently in Development
A leading vaccine developer in the United States is Moderna. Moderna and BioNTech, having achieved success with their COVID-19 vaccines, are now leveraging their mRNA expertise to develop novel vaccines for influenza, RSV, EBV, HSV, HIV, malaria, and even cancer. Additionally, Moderna’s mRNA-1647 vaccine is currently in phase 3 clinical trials for the treatment and prevention of CMV infection in women.
Other innovative biotechs like CureVac are also advancing mRNA and self-amplifying RNA technologies for infectious diseases and oncology. Beyond mRNA, companies like Valneva and Bavarian Nordic are making strides with traditional and novel vaccine approaches, targeting diseases such as chikungunya and Lyme disease. The field is also seeing significant activity from companies like MinervaX in Group B Streptococcus and Evaxion Biotech utilizing AI for vaccine discovery.
Understanding Global Immunization
According to the World Health Organization (WHO), as of 2023, there were 14.5 million children who had not received any vaccination, who are often referred to as zero-dose children. They report that the COVID-19 pandemic has had drastic effects on vaccination rates as a whole, and we have yet to return to 2019 vaccination levels.
In the United States, at least 81% of the population are reported to have received at least one dose of the vaccine for COVID-19. This percentage is much lower in countries without the same access to healthcare.
When discussing the global vaccination landscape, it would be irresponsible not to acknowledge that access to vaccines, and healthcare in general, is not a universal truth. Many individuals, especially those in third-world countries, struggle to gain access to the life saving vaccines many of us take for granted.
The Future of Vaccines
The future of vaccines is being reshaped by biotechnology, moving towards precision and versatility. In the near future, we anticipate a greater prevalence of mRNA and DNA vaccines for infectious diseases and cancer immunotherapy. mRNA vaccines deliver genetic instructions for protein production, while DNA vaccines introduce genetic material for a similar outcome.
Personalized vaccines represent another significant leap forward, tailoring immunizations to individual profiles or specific tumor mutations. For infectious diseases, this could mean enhanced efficacy and fewer side effects based on an individual's genetic and immune makeup.
In cancer immunotherapy, personalized vaccines targeting unique tumor neoantigens aim to trigger a specific immune attack on cancer cells. Complementing this are innovative, needle-free delivery methods like microneedle patches and nasal sprays, which promise improved accessibility, ease of administration, and potentially enhanced mucosal immunity.
Finally, the pursuit of universal vaccines for viruses like influenza remains a critical goal, aiming for broad and long-lasting protection against multiple strains. Additionally, artificial intelligence and big data are poised to revolutionize vaccine discovery and design. AI can accelerate target identification, antigen design, and adjuvant discovery, while big data analytics can optimize clinical trials and predict vaccine efficacy, ushering in a new era of faster and more effective vaccine development.
Streamline Your Vaccine Development & Manufacturing
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About HPNE
As the industry needs grow, High Purity New England, Inc. continues to supply the biopharmaceutical industry with a range of innovative products, from drug discovery and development to fill-finish, including their flagship product, custom single-use assemblies, as well as pumps, sensors, bioreactor systems, storage and handling solutions and other single-use solutions. Along with their own manufactured products for the global market, they are also a distributor for more than 18 brands in North America.
