History of Vaccines

Vaccines have revolutionized global health, eradicating viruses like smallpox and nearly eliminating poliovirus - diseases that previously killed millions of people. The number of people who contract preventable infectious diseases like measles, diphtheria and whooping cough is at an all-time low, thanks to vaccines.

The COVID-19 vaccine began distribution around the world in December 2020, nearly one year after the illness was first recognized as an outbreak in Wuhan, China.

COVID-19 vaccines are being distributed in a priority approach, immunizing healthcare professionals, frontline workers and those most vulnerable first. The COVID-19 vaccine was put on a fast track, but it was still developed under the same stringent process all modern-day vaccines are, which have been proven safe and effective for decades.

What steps go into developing a vaccine? And when was the first vaccine invented? We're answering these questions by taking a look at the history of vaccines and how they've made the world a healthier place.

When were vaccines invented?

When looking at the history of vaccines timeline you can start in 15^th century China. The Chinese recognized that people who survived smallpox did not get the disease again. They decided to take smallpox scabs from people who had mild cases, dry them out, grind them into a powder and blow the powder up the nostrils of healthy people. The effectiveness of these early vaccination efforts is not well-known, but they had the right idea: taking a weaker version of the virus, and introducing it to healthy people to allow their immune system to build up antibodies (cells that fight off the virus).

When was the first vaccine created?

A more sophisticated take on vaccinations can be traced back to the late 18^th century. From there, vaccines have made leaps and bounds of progress. Here is a look at the vaccine timeline over the past 225 years.

• 1796 - Dr. Edward Jenner collected bits of cowpox pustule—the animal variant of smallpox - from the arm of a milkmaid named Sarah Nelmes and scratched it into the arm of an 8-yar-old boy.
• 1881 - French Biologist Louis Pasteur developed a successful vaccine against anthrax. Pasteur exposed anthrax pathogens to heat and oxygen to weaken, but not kill them.
• 1885 - Pasteur developed a successful vaccine against rabies. Pasteur used the same approach he did for the anthrax vaccine.
• 1914 - Pertussis, or whooping cough, vaccine is developed.
• 1926 - Diphtheria vaccine is developed.
• 1938 - Tetanus vaccine is developed.
• 1948 - Pertussis, diphtheria and tetanus vaccines are combined and given as the DTP vaccine.
• 1955 - Jonas Salk develops a break-through polio vaccine based on a dead poliovirus.
• 1963 - Measles vaccine is developed.
• 1967 - Mumps vaccine is developed.
• 1969 - Rubella vaccine is developed.
• 1977- The smallpox vaccine is no longer recommended. Because of the vaccine's success, the disease is considered eradicated.
• 1981 - Hepatitis B vaccine is developed.
• 1996 - Chickenpox vaccine is developed.
• 1998-1999 - Rotavirus vaccine is developed.
• 2000 - Hepatitis A vaccine is developed.
• 2000 - Polio vaccine is no longer recommended. Because of the vaccine's success, the disease is no longer considered a threat.
• 2001 - Pneumococcal vaccine is developed.

The 2020 recommended vaccination list is as follows[JM1] :

• Diphtheria*.
• Tetanus*.
• Pertussis*.
• Measles**
• Mumps**
• Rubella**
• Polio (IPV)
• Hib
• Hepatitis B
• Human Papilloma Virus (HPV)
• Varicella
• Hepatitis A
• Pneumococcal
• Influenza
• Rotavirus
• Meningococcal ACWY
• Meningococcal B

*Given in combination as DTaP

** Given in combination as MMR

Vaccine Safety

Safety precautions have been developed and implemented alongside the development of vaccines. Vaccines in the United States are tested extensively and reviewed by the Food and Drug Administration (FDA) before being distributed to the public[JM3] . Vaccine development in the United States follows this process:

1. Research, discovery and pre-clinical studies are performed. Every company that wishes to develop a vaccine and begin clinical trials must submit an Investigational New Drug application (IND) to the FDA. The IND describes the vaccine, how it will be manufactured and quality control tests for release.
2. Clinical studies and trials
• Phase 1 - Trials are small, involving between 20-100 volunteers and last a few months. The goal of phase 1 trials is to evaluate basic safety and identify any common reactions.
• Phase 2 - Trials involve several hundred participants. This can last anywhere from a few months to two years[JM4] . Phase 2 studies evaluate safety and efficacy. Data gained in this phase inform the composition of the vaccine and how many doses are necessary.
• Phase 3 - Trials involve several thousand volunteers. This can sometimes last for years. This stage finalizes safety and efficacy of the vaccine.
3. FDA Review - Once clinical trials have deemed a vaccine safe and effective[JM5] , the manufacturer submits a Biologics License Application (BLA) and an application for the production plant to the FDA. The FDA reviews the clinical trial information. Only after the FDA reviews the application, inspects the production facility and determines everything safe is the vaccine licensed for use in the general population.
4. ACIP Review - After the FDA licenses a vaccine, the Advisory Committee on Immunization Practices (ACIP), which is composed of a group of medical and public health experts, develops recommendations on how to use vaccines to control disease in the United States. The ACIP recommendations are sent to the CDC and U.S. Department of Health and Human Services for approval. Once approved, these recommendations are used as final and official CDC guidance for immunization of the U.S. population.
5. Post-approval, monitoring and research
• Phase 4 - A sample from every vaccine lot is submitted to the FDA prior to its distribution for review. The ACIP continues to monitor vaccine safety and effectiveness.

The vaccine development timeline can take years, but in instances like COVID-19, efforts are expedited. Even though the process goes faster than normal, all of the steps to ensure safety and efficacy are still followed.

Vaccinations can save your life and the lives of others. To make sure you are up to date with your vaccinations, schedule an appointment with your doctor. Call (765) 935-8934 or request an appointment online.