Vaccines have changed the course of human history. Before their discovery, infectious diseases caused the disability and death of countless adults and children who lacked the immune defenses to fight them.
By exposing them to substances that induce a sustained immune response, vaccinated people were largely protected from infection or serious illness from these deadly infections.
The first vaccines, introduced in the 18th and 19th centuries, ushered in an era during which scientists gained a deeper understanding of the immune system and how to stimulate the production of disease-fighting cells called antibodies .
Armed with this knowledge, scientists have been able to create new vaccines that elicit this response in many different ways, including the technologies that led to the development of COVID-19 vaccines . In some cases, herd immunity in vaccinated populations has led to the complete eradication of certain diseases that once killed millions.
18th and 19th centuries
The concept of vaccination and immunization predates much of what is commonly known as the "age of vaccines."
As early as the 11th century, historical records showed that the Chinese practiced variolation, a method by which small amounts of pus from people with smallpox are injected into the bodies of people who do not have smallpox. Therefore, people exposed to small amounts of the virus were largely protected from the ravages of the disease. However, some became ill and even died .
The practice of variolation soon spread from China to the Ottoman Empire. In the late 18th century, this was taught to English travelers in Turkey, who introduced the practice to the British Empire and later to America.
But the actual development of vaccines – substances that provide immune protection without minimal risk of disease – didn't begin until the late 18th century.
Among the iconic moments in the early history of vaccination:
- Edward Jenner developed the first smallpox vaccine in 1796. He found that by inoculating people with vaccinia, a similar virus that only causes mild illness, they were largely immune to the effects of the deadliest disease.
- Louis Pasteur developed a rabies vaccine in 1885 after creating the first laboratory vaccine for chicken cholera in 1879. For the rabies vaccine, Pasteur used a live attenuated (weakened) virus to induce an immune response.
- The cholera vaccine was developed by the Spanish physician Jaime Ferran in 1885 and is the first vaccine to immunize humans against a bacterial disease.
- The typhoid vaccine was developed in 1896 by scientists Richard Pfeiffer and Wilhelm Collet using whole, killed (inactivated) bacteria .
1900 to 1979
The early 20th century saw rapid advances in vaccine research, thanks in large part to technology that allowed scientists to isolate and distinguish between different viruses or bacteria. This allowed scientists to distinguish, for example, measles from smallpox, a discovery made only in 1900 by the Persian scientist Razes.
Among the key advancements in vaccines in the early and mid-20th century:
- The first diphtheria vaccine was developed in 1913 thanks to the work of Emil Adolf von Bering (Germany), William Hallock Park (USA), and other scientists.
- The first whole cell vaccines against pertussis were developed in 1914, although it will be several decades before they are widely used.
- The first successful tetanus vaccine was developed in 1927 based on von Bering's research in the 1890s.
- Max Tyler develops the first vaccine against yellow fever in 1936.
- The first influenza vaccine was licensed for use in 1945. Scientists Thomas Francis Jr. and Jonas Salk were among the scientists who spearheaded the development of this inactivated whole virus vaccine.
- In 1948, separate vaccines for diphtheria, tetanus, and pertussis were combined into a single DPT vaccine. This is the first time that vaccines have been combined to ease the vaccination burden for children and adults.
- Salk developed the inactivated polio vaccine (IPV) in 1955.
- The live oral polio vaccine (OPV), developed by Albert Sabin, replaces the Salk vaccine in 1962.
- The first live attenuated measles vaccine was developed by John Enders in 1963, of which 19 million doses were distributed over the next 12 years.
- In 1967, Maurice Hilleman developed the mumps vaccine, of which 11 million doses were distributed over the next five years.
- Maurice Hillemann is also leading the development of a rubella (German measles) vaccine, licensed for use in 1969.
- The combined measles, mumps, and rubella (MMR) vaccine was licensed for use in 1971.
- Pneumovax, the first pneumococcal vaccine to protect against certain types of Streptococcus pneumoniae, was approved in 1971. It is still used today in high-risk children.
- Elimination of the virus. In 1979, smallpox became the first declared disease eradicated by the World Health Assembly. The last case occurred in 1977, with a Somali man with a very mild illness.
1980 to 2000
With the eradication of smallpox in 1979, scientists have tried to do the same for many other diseases. In doing so, they were aided by rapid advances in technology that allowed researchers to closely examine the mechanisms that trigger an immune response, right down to the genetic sequence of a cell.
Among the achievements of the second half of the 20th century:
- Menomune, the first meningococcal vaccine , was licensed for use in 1981 and is fast becoming the standard for preventive care for high-risk children until it is superseded by Menactra in 2005.
- The hepatitis B vaccine was licensed in 1981 and becomes the first subunit vaccine to elicit a protective immune response with only part of the hepatitis B virus.
- The first recombinant hepatitis B vaccine, called Recombivax HB, was approved in 1986. Unlike traditional vaccines, which use a live or dead organism to trigger an immune response, recombinant vaccines insert DNA into cells to encode instructions about how to create disease-specific antibodies.
- The first Haemophilus influenzae type b (Hib) vaccine is licensed for use. It is classified as a conjugate vaccine that combines two different antigens (in this case, inactivated Hib with proteins from other infectious bacteria) to elicit a more robust immune response.
- In 1989, a booster dose of the MMR vaccine was recommended to children living in counties with at least five measles cases to accelerate measles eradication.
- In 1993, the first quadrivalent combination vaccine (four in one) was approved, called Tetramun, which combines the DTP and Hib vaccines. Subsequent combinations include Pediarix (DTaP, polio, hepatitis B) in 2004, ProQuad (MMR, chickenpox) in 2006, Pentacel (DTaP, polio, Hib) in 2008, Kinrix (DTaP, polio) in 2008, and Vaxelis (DTaP, polio ). , hepatitis B, Hib) in 2018
- Elimination of the virus: In 1994, the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) announced that polio had been eradicated in the Western Hemisphere.
- The first varicella ( chickenpox ) vaccine, called Varivax, was licensed for use in the United States in 1995 (although vaccination against the disease had already begun in Japan and Korea in early 1988).
- The first hepatitis A vaccine , called VAQTA, was approved for use in 1996.
- In 1996, the Salk polio vaccine was again recommended for use due to the small risk of vaccine-associated paralytic polio (VAPP) associated with oral polio vaccine.
- A safer version of DTP, called DTaP , was licensed for use in 1997. Instead of using all of the pertussis bacteria, DTaP uses a subunit of pertussis called acellular pertussis.
- LYMErix, a Lyme disease vaccine , was licensed for use in 1998 (although production was discontinued in 2002 due to declining sales and concerns about side effects).
- Virus Elimination: Declared elimination of measles in the United States in 2000.
Until now, the 21st century has been marked by contrast when it comes to vaccines. For one thing, vaccine development has snowballed with an ever-expanding set of vaccine platforms to build on. On the other hand, the rejection of vaccination by many broad masses has led to the return of diseases that were once declared eradicated.
Some of the achievements of the early 21st century include:
- FluMist , an intranasal flu vaccine, approved in 2004. Unlike flu vaccines that are given with an inactivated virus, FluMist includes a live attenuated virus.
- Eradication of the virus: In 2004, the United States announced the elimination of endemic rubella .
- The Tdap vaccine was approved for use in 2006. While it protects against the same diseases as DTaP, it is used primarily as an immunity booster in the elderly. The pneumococcal vaccine is another case in which revaccination is recommended for adults 65 years of age and older .
- Gardasil, the first vaccine to protect against the human papillomavirus (HPV) , was approved in 2006. It is followed by Cervarix (discontinued production in 2016) and Gardasil-9 (an improved version that replaced the original Gardasil in 2017) .
- In 2011, the Fluzone High-Dose flu vaccine was approved for use in the elderly, who tend to be less resistant to traditional flu vaccines and are more likely to face serious complications from flu .
- Zostavax , a live attenuated vaccine against shingles (shingles) , was approved for use in 2011. It was considered the standard of preventive care until a safer and more effective inactivated vaccine called Shingrix was released in 2017 (the manufacturer voluntarily discontinued Zostavax in November 2020 and is no longer available in the United States ) .
- With the emergence of more virulent strains of influenza and declining efficacy of vaccines, quadrivalent influenza vaccines became the standard of care in 2013.
- Trumenba, the first vaccine to protect against serogroup B meningococcal disease, was licensed for use in 2014. When used with vaccines that protect against serogroups A, C, W, and Y, Trumenba can prevent life-threatening complications in groups of high risk. – especially during outbreaks of meningitis in colleges and universities .
- Fluad is the first adjuvant influenza vaccine to be used only in adults 65 years of age and older. Approved for use in 2015, it no longer contains antigens like Flublock High-Dose. Rather, it includes a non-antigenic substance called an adjuvant that enhances the overall immune response to the flu vaccine .
- On July 14, 2020, the Modern COVID-19 vaccine will be the first emergency vaccine (USA) approved by the United States Food and Drug Administration (FDA) to prevent COVID-19. It is also the first vaccine successfully built on a messenger RNA (mRNA) platform .
- On August 12, 2020, the Pfizer / BioNTech COVID-19 vaccine, also an mRNA vaccine, will be the second vaccine to receive the US state .
- On February 27, 2021, the Janssen / Johnson & Johnson COVID-19 vaccine will receive USA status. Unlike the other two vaccines, this is a recombinant vector vaccine that delivers a fragment of COVID-19 into cells via an attenuated cold virus .
Despite improvements in vaccine safety and efficacy, growing anti-vaccination sentiment in the United States has led to declining vaccination rates and a resurgence of diseases once thought to be eradicated.
In 2019, a measles outbreak in 22 states resulted in 1,281 confirmed cases, an alarming setback from 2000, when the disease was officially declared eradicated in the United States.
Public health officials fear the same could happen with other diseases, believed to be eradicated.
Get the word of drug information
Vaccines work. Despite conspiracy theories and claims to the contrary, the benefits of recommended vaccines invariably outweigh the risks.
Keep in mind that a disease like diphtheria killed more than 15,000 children in the United States in 1921, but it is rare, if ever, today. (The last two cases were reported in 2004 and 2015). Or what disease like polio, which in 1916 caused more than 2,000 deaths in New York City alone, has made many history books .
COVID-19 Pandemic 2020-2021 It easily reminds us that vaccines not only protect people from serious illness and death, but also protect the general population by preventing the spread of infection.
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