Consumer interaction with vaccines typically starts and ends with the shot at the doctor’s office. Many patients do not know the work that is required not only to manufacture a vaccine, but to create the vaccine base itself. Years of both research and development go into every immunization.
So what goes into a vaccine before you get it? And how is its development continued throughout the vaccine’s lifespan?
What are Vaccines and How do They Work?
Before discussing vaccine development, it’s key to understand what a vaccine is.
When it comes to the name, people may often use terms like “vaccine”, “vaccination” and “immunization” interchangeably. But, a vaccine specifically is a product that produces immunity from a disease.
Essentially, vaccines give your body a tiny taste of the real deal now. The body then learns how to fight the disease later on if a proper threat is posed by it in the future. In most cases, this act helps give the body immunity to infection from that illness. This is why the term “immunization” refers to any process by which a person becomes protected from a disease.
Commonly, vaccines are given through vaccinations, which are injections of a killed or weakened organism that produces immunity in the body against that organism. Other vaccines may use only specific parts of a disease’s germ, or work with the germ’s toxin itself.
There are some alternative vaccine delivery methods to shots. Liquid and nasal spray forms can offer the same or a similar protection against the illness. Other methods, like small Band-Aid-like patches have also shown early success in experiments, with more ways potentially on the way.
What Goes Into Vaccine Development?
Numerous groups of people are involved in vaccine development. Health professionals, academia, manufacturers and private industry workers all help put vaccines together. Government agencies, nongovernmental organizations and media persons also aid with the development process. Finally individuals and communities are crucial in both development and testing.
While the process is complex and extensive, the main stages of vaccine development are:
- Exploratory Stage – Basic laboratory research takes place during this stage. Professionals look to find natural or synthetic antigens which may help treat or prevent a disease. History of Vaccines describes that these antigens may be weakened viruses or bacteria, weakened bacterial toxins, virus-like particles or other substances which originate from pathogens. The exploratory stage lasts two to four years.
- Pre-Clinical Stage – Officials begin testing with animals and tissue-culture or cell-culture systems. Researchers then get an idea of the immune response they can expect the potential vaccine to provoke in humans. Many times, a potential vaccine will not make it past this stage because the immune response shown is not right. This stage will last one to two years. When successful, the pre-clinical stage is also used to find the method which should be used for vaccine delivery. They will also discover the safe dosage to use for the next phase of testing.
- Clinical Development –
- Phase I – a phase with small groups of people receiving the trial vaccine.
- Phase II – an expanded trial group with vaccination recipients who display similar characteristics to potential vaccine users.
- Phase III – a considerably larger phase with thousands of vaccination recipients. Testing is focused on efficacy and safety.
- Phase IV – a phase which many companies choose to use to conduct extra, ongoing studies after the vaccine has already been approved and licensed.
- Regulatory Review and Approval – This step can only come after detailed applications and rigorous demonstration of Good Manufacturing Practices. Regulatory review and approval processes then allow the manufacturer to receive FDA licensing. The process includes an Investigational New Drug application, pre-licensure vaccine clinical trials, a BLA (Biologics License Application), inspection of the manufacturing facility, presentation of findings and usability testing of product labeling.
- Manufacturing – During this part of the process, vaccines are made. Manufacturer Sanofi Pasteur shares that their production takes between six and 36 months. Several hundreds of quality tests will take place during that span. In total, 70% of production time dedicated to quality control.
- Quality Control – Using information from the public and healthcare providers, quality control continues through different agencies/methods long after a vaccine is licensed, manufactured and distributed.
What Happens After Vaccine Development?
As soon as public vaccine use starts, vaccine performance is constantly checked. Multiple systems and organizations monitor and test the vaccine.
But, there are several major ways vaccine safety and effectiveness can be confirmed after its initial release.
For example, many companies will choose to do Phase IV vaccine development. This means they conduct extended studies after a vaccine is already approved and licensed. Phase IV testing helps further quality control efforts. Those involved can gain a greater scope of valuable information on the vaccine.
Other well-known avenues for vaccine safety monitoring include the VAERS (the Vaccine Adverse Event Reporting System) and the VSD (the Vaccine Safety Datalink).
Co-sponsored by the FDA and the CDC, the VAERS allows anyone from friends of a patient to a healthcare professional to report adverse reactions to vaccines. About 30,000 events are reported each year, though only about 3,000 to 4,500 of these cases involved serious medical events. After receiving a report, the CDC investigates the event to determine whether the event was actually connected to the vaccination.
The VSD allows the CDC to receive valuable vaccine information from eight major healthcare organizations. This information includes the kind of vaccines given to patients, the date the vaccine was given and more. The CDC will then use reports from the VAERS to publish safety studies on vaccines. The studies will focus on newer vaccines, or vaccines for which recommendations have changed.
Why Are Vaccines so Important?
The positive impact of vaccinations has been well-documented across the world.
The WHO has shared their estimation that at least 10 million deaths were prevented between 2010 and 2015 due to global vaccinations. They stated, “There is arguably no single preventive health intervention more cost-effective than immunization.”
In the U.S. alone, the CDC believes that the vaccination of American children born between 1994 and 2018 will prevent 419 million illnesses. That includes 26.8 million hospitalizations and 936,000 deaths. The decreased cases will also save nearly 1.9 trillion dollars in total societal costs.
Did you know anything about vaccine development before this article? Had you realized there were so many steps to the process? Let us know in the comments below, or via Facebook and Twitter.
Images created by MPH@GW, the online MPH program from the George Washington University
Written for Passport Health by Katherine Meikle. Katherine is a research writer and proud first-generation British-American living in Florida, where she was born and raised. She has a passion for travel and a love of writing, which go hand-in-hand.