The development of vaccines takes a lot of time, hard work, experiments, and trial and error. A fundamental principle for vaccination says sufficient vaccination leads to minimal risk of vaccine-preventable disease. There is a definitive cause-and-effect relationship between vaccination and its effect on the emergence of disease in individuals and populations.
The Importance of Vaccines
The story begins with a vaccine utilized in 1992 in response to an outbreak of bacterial meningitis on college campuses. In the middle of the influenza season (February 1992), in a span of 72 hours, two university students came down with severe flu-like symptoms.
However, one unusual feature of their illness was a strange rash on different parts of their body. This was not typical for routine influenza. Alarm bells went off regarding the possibility of a devastating bacterial infection, known as meningococcemia.
Unfortunately, both students—who had previously been completely healthy—succumbed to their illnesses within 48 hours despite everything the doctors and nurses did. And over the next 16 months, a total of nine students in that town were stricken with the meningococcal bacterial disease.
This is a transcript from the video series An Introduction to Infectious Diseases. Watch it now, on Wondrium.
The Source of the Deadly Germ
In conjunction with the Centers for Disease Control (CDC), an epidemiological study was undertaken to look for the source of the deadly germ. The discovery of a common link (the campus bar), advanced medical knowledge about this deadly bacterial disease.
The investigation findings were published in the American Journal of Epidemiology. It concluded that all students who contracted the disease had the same strain of meningococcal—serogroup C. They all frequented the same bar, and they spent an average of 12 hours a week in bars, compared with the student control group who averaged two hours a week.
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Reasons Behind the Bacteria Outbreak
Neisseria Meningitidis bacteria is common since it is carried by 15 percent of the student population in their nose or throat passages without causing illness. The invasive serious disease is actually very rare (one case/100,000 population/year). So, what made this suddenly turn into an outbreak?
There is ample medical evidence suggesting that crowded dormitory and bar conditions have made it easier to communicate the disease. Patrons are exposed to coughing, sneezing, and other germ-spreading actions. Another possibility is the consumption of alcohol or cigarettes may make it easier for the germ to pass across the throat’s mucous membranes, and then enter the bloodstream.
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With germs, this dangerous disease can quickly spread within hours of its first symptoms and can cause organ failure and bacterial meningitis. In 1992, as a result of collaboration with the CDC, 18,000 university students were vaccinated with a sugar-based, or polysaccharide, meningococcal vaccine.
Subsequently, the vaccination campaign continued over the next three years. The effectiveness of the vaccine was proven when no additional cases occurred after the mass vaccination for over four years.
Thereupon, and pursuant to several other outbreaks on college campuses, the CDC and immunization committees started routinely recommending the meningococcal vaccine for first-year college students nationwide. And this was eventually extended to teenagers as well.
Creation of the Smallpox Vaccine
Edward Jenner, at the turn of the 19th century, ingeniously created the smallpox vaccine that used cowpox to protect against the disease, but not cause serious illness. There was skepticism in early America about the efficacy of the vaccine.
So, the Board of Health of Boston formulated a clinical trial of the vaccine to prove or disprove its effectiveness. This institution was founded in 1779 and chaired by no other than Paul Revere. To prove effectiveness, they put 15 boys into a room; two of whom were unvaccinated, and the other 13 were vaccinated.
They were all exposed to the smallpox virus. The two unvaccinated boys, not unexpectedly, became ill but did not die, and the other 13 remained healthy. This was the first controlled human trial that convinced the public that the vaccine really worked and was safe, although this experiment might generate some ethical discussions today.
In the late 19th century, a new live vaccine derived from a similar virus—the vaccinia virus—replaced cowpox. It starts giving protection against smallpox a few days after it is administered. It provides immunity for at least three to five years and longer if booster shots are injected.
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The Process of Vaccine Development
This process includes oversight by the Food and Drug Administration, or FDA, in collaboration with the CDC’s Immunization Safety Office. The exploratory stage usually lasts two to four years and consists of basic laboratory research. Scientists identify natural or synthetic antigen proteins as targets.
Pre-clinical activities involve the use of cultures and animals to assess the safety and may be carried out in mice or monkeys. Many vaccines never get beyond this point. And if they do, the sponsor submits an application for an Investigational New Drug to the FDA.
If approved, it goes through three stages of rigorous testing, including clinical studies with human subjects in small, then medium, and larger groups. Of course, the safety, as well as the efficacy, are both tested. And if successful, it is usually approved.
In order to stimulate more vaccines to be developed in the United States, the government removed liability responsibility from pharmaceutical developers for approved vaccines. The U.S. has a nationwide vaccine damage reimbursement strategy, and volunteers today get money if they are injured during the testing procedure.
Common Questions about the Development of Vaccines in the US and Beyond
In 1992, 18,000 university students were vaccinated with a polysaccharide meningococcal vaccine. This vaccination campaign continued over the next three years and the effectiveness of the vaccine was proven when no additional cases occurred after the mass vaccination for over four years.
At the beginning of the 19th century, Edward Jenner helped the development of vaccines by ingeniously creating the smallpox vaccine out of cowpox. It protected against the disease without causing serious symptoms.
In order to encourage the development of vaccines in the United States, the government removed liability responsibility from pharmaceutical developers for approved vaccines.