Vaccines have saved countless lives over centuries of use and research

In America today, parents no longer fear that smallpox, polio or diphtheria might cripple or kill them or their children. Routine vaccinations keep those diseases, as well as mumps, pertussis (whooping cough), measles, hepatitis, tetanus, influenza, HPV (human papillomavirus), rubella (German measles) and others at bay.

“Pandemics and other significant outbreaks make it clear the vital role that vaccines play in protecting our communities,” said Benjamin R Levin, MD, Cape Cod Healthcare’s new chief quality officer.

Vaccines have once again played a part in mitigating a worldwide epidemic with the development of vaccines for COVID-19, he said.

“Vaccines are one of our most powerful weapons in the fight against the ever-evolving pathogens that we encounter, and our ability to mass produce them rapidly continues to improve,” said Dr. Levin. “The speed and efficiency with which the COVID-19 vaccines were developed gives me confidence in our ability to answer these threats effectively in the future.”

But it wasn’t so long ago when epidemics of the diseases listed above swept through communities, without the benefit of vaccines to blunt their deadly force. 

British physician Edward Jenner gets credit for starting the modern era of vaccination. In 1796, he inoculated an 8-year-old boy with matter from pustules from a similar illness, cowpox, on a young milkmaid. It was known that milkmaids seemed to be resistant to catching smallpox. After a few days, the boy fell mildly ill, then recovered. Jenner inoculated him again, this time with matter from a an actual smallpox sore. The boy remained healthy and Jenner concluded cowpox infection had protected the boy from smallpox and that cowpox and smallpox were closely related. Although his theory was rejected at first by some British medical leaders, successful results gradually boosted support, and inoculation against smallpox spread across Europe and the United States.

The practice of inoculation to protect against smallpox predates Jenner by hundreds of years, well before the discovery that bacteria and viruses cause many diseases and can be spread from an infected person to others, or any inkling of how our body’s immune system works to combat pathogens.

Accounts from the 1500s report inoculation against smallpox in India and China, and it may have been practiced as early as 200 B.C. It was also used in Africa. A report from the late 1600s describes Chinese Emperor K'ang Hsi having his children inoculated by having ground smallpox scabs blown into their nostrils. He became emperor when his father died of smallpox; K’ang had already survived smallpox. The Chinese also used variolation, or scratching matter from a smallpox sore onto the skin of an uninfected person.

Lady Mary Wortley Montagu introduced variolation to England from Turkey, where her husband was an ambassador. Smallpox had previously scarred her face and killed her brother. When she and her husband returned to England in 1721, she had the embassy surgeon inoculate their 5-year-old son as physicians of the royal court watched. That was 75 years before Jenner’s experiment.

Variolation became popular among European titled classes, despite its risks. An estimated 2-3 percent of inoculated people died of smallpox. Others got sick and spread the disease. The practice sometimes transmitted other diseases, including tuberculosis and syphilis. Still, the risk of dying from naturally caught smallpox – 20-30 percent – dwarfed that of dying from smallpox inoculation.

Integral to U.S. History

Epidemics, inoculations and vaccines shaped America. A 2019 study published in Quaternary Science Reviews estimates after Christopher Columbus began traveling to the Americas in 1492, by 1600 about 56 million natives had died of disease the visitors brought – known as the “Great Dying.” Communicable disease facilitated European occupation of native lands and played a role in warfare.

During the Civil War twice as many soldiers died from disease than battle injuries, according to the National Park Service.

Consider these dates:

• 1625 – Jesuits in Canada report Native Americans blame colonists for smallpox outbreaks that wiped out villages closest to European settlers. In 1633, an epidemic hits Massachusetts colonists and natives.
• 1777 - George Washington, commander-in-chief of the Continental Army, ordered soldiers that had never been infected by smallpox to be inoculated.
• 1813 - Congress passes a law, signed by President James Madison, to create a federal vaccine agency.

From the late 1800s, progress on understanding communicable diseases and development of vaccines proceeded at an increasing pace. Some highlights, many collected by The College of Physicians of Philadelphia, include:

• 1879 – French scientist Louis Pasteur creates the first laboratory-produced vaccine, using a weakened (or attenuated) bacteria for chicken cholera.
• 1884 – Pasteur prevents rabies in dogs with a vaccine.
• 1913 – German scientist Emil von Behring creates a diphtheria vaccine after having developed treatments for diphtheria and tetanus using the serum (plasma) of infected animals.
• 1918 – Influenza pandemic infects one-third of the world’s populations and kills an estimated 50 million.
• 1935 – Trials of two different polio vaccines sicken, paralyze and kill many subjects.
• 1936 – Max Theiler creates an attenuated live vaccine for yellow fever. His method of growing the virus in fertilized chicken eggs for mass production become the standard for vaccines.
• 1939 – Whooping cough vaccine shown to be effective.
• 1945 – First flu vaccine approved for the military; approval for civilian use follows the next year.
• 1955 – Government approves use of the Salk polio vaccine in March, but suspends vaccination in May after 11 people die and hundreds are paralyzed. Investigation results in more stringent controls on vaccine production and testing.
• 1958 – Boston researchers try measles vaccine on disabled and developmentally delayed children, some of whom develop measles symptoms, but not full measles. Researchers realize they need to further weaken the virus in the vaccine.
• 1965 – Philadelphia researchers try experimental mumps vaccine at area institutions for mentally disabled people.
• 1972 – Routine immunization for smallpox stops, and in 1980, the World Health Assembly declares the disease eliminated.
• 1994 – Pan American Health Association declares polio eradicated from the Americas.
• 2000 – Measles naturally arising from domestic transmission (endemic) purged from the United States, but threat from overseas visitors remains.
• 2014 – Measles infections in U.S. hit 644, the highest levels since elimination declared.
• 2017 – World Health Organization reports 35 measles deaths in Europe, most from Romania, where vaccination levels were low. Italy logs 3,300 infections in the first half of the year.
• 2019 – In December, Chinese officials report a group of pneumonia cases in Wuhan, later traced to a newly discovered coronavirus, SARS-CoV-2. The disease it causes is named COVID-19.
• 2020 – In December, the U.S. Food and Drug Administration give its first emergency use approval for a vaccine made by Pfizer-BioNTech to prevent COVID-19. About a week later, the second such approval follows, this time for a vaccine made by Moderna. Both require two doses. In late February 2021, the FDA issues its third emergency approval of a COVID-19 vaccine. The Johnson & Johnson Janssen vaccine requires only one dose, but carries the rare risk of causing serious blood clots.
• 2021 – Polio no longer endemic in any of the world’s nations except Afghanistan and Pakistan. Vaccines estimated to have prevented 18 million cases.
• 2021 – The Centers for Disease Control and Prevention states that as of Aug. 5, 348.9 million doses of COVID-19 vaccines have been given in the U.S. An estimated 58.2 percent of the population has received at least one dose. As of Aug. 4, 612,958 U.S. deaths from COVID-19 reported.

The path forward for vaccines was dotted with mistakes and errors, and opposition to them waxed and waned. However, scientists responded to setbacks and criticism by making vaccines safer, and health experts hail their overwhelming success in preventing disease. While no vaccine is 100 percent effective or without risk, “the benefits of vaccines far outweigh the risks,” according to the CDC.

Approved and Monitoring

The process by which the FDA now approves vaccines consists of three phases of trials for:

• Safety
• Dosage
• Common reactions
• Effectiveness.

These trials can take several years and involve thousands of volunteer subjects.

Prior to all human testing, researchers use computer modeling and animal tests. If the three trial phases on human volunteers are completed successfully, the FDA studies the data produced and proposed procedures to make the vaccine. If the FDA then decides to license the vaccine, an advisory committee of public health and medical experts makes recommendations on the vaccine’s use to the CDC’s director and the U.S. Department of Health and Human Services for further review and approval.

After a vaccine is approved and placed in use, the advisory panel continues to monitor data on the vaccine’s safety and effectiveness. Manufacturers send the FDA samples from each lot along with test results for purity, strength and safety. To continually look out for side effects and other potential health risks, the CDC uses three networks to collect information from patient reports, the FDA, several health organizations and medical research centers.