How do vaccines work? - Kelwalin Dhanasarnsombut

Summary

This script narrates the history and function of vaccines, starting from Edward Jenner's pioneering work in 1796. It explains the immune system's response to pathogens and how vaccines leverage this by triggering adaptive immunity without causing disease. The script covers various vaccine types, including live attenuated, inactivated, subunit, and the innovative DNA vaccines, which use genetic material to instruct cells to produce antigens and prepare the body for future threats, potentially leading to treatments for currently untreatable diseases.

Takeaways

• 💉 The first vaccine was developed by Edward Jenner in 1796, using cowpox virus material to inoculate against smallpox.
• 🛡️ The immune system's two lines of defense are the innate response and the adaptive immunity involving B cells and T cells.
• 🤒 Symptoms like coughing, sneezing, inflammation, and fever are part of the body's innate immune response to trap and remove foreign microbes.
• 🧬 Vaccines work by preparing the body's immune system to recognize and fight off pathogens without causing the full disease.
• 🔬 There are different types of vaccines: live attenuated, inactivated, subunit, and the emerging DNA vaccines.
• 🌱 Live attenuated vaccines use a weakened form of the pathogen to stimulate an immune response.
• 💀 Inactivated vaccines contain pathogens that have been killed, still capable of triggering an immune response without causing disease.
• 🧬 Subunit vaccines are made from specific antigens, parts of the pathogen that trigger the immune system, for more targeted responses.
• 🧬 DNA vaccines involve injecting genes that instruct the body's cells to produce antigens, leading to a strong immune response.
• 🚫 Live attenuated vaccines may not be suitable for individuals with compromised immune systems.
• 🔄 Inactivated vaccines might not provide long-lasting immunity compared to other types.
• 🔬 The development of new vaccines, like DNA vaccines, could pave the way for more effective treatments against currently untreatable diseases.

Q & A

Who is credited with the first-ever vaccine development?

Edward Jenner is credited with the first-ever vaccine development in 1796.

What was the initial purpose of Edward Jenner's cowpox virus injection into the eight-year-old boy?

The initial purpose was to provide protection against the deadly smallpox virus by using the related but less harmful cowpox virus.

How does the immune system respond to foreign microbes?

The immune system triggers a series of responses to identify and remove the microbes, which can manifest as coughing, sneezing, inflammation, and fever.

What are the two lines of defense in the immune system as described in the script?

The two lines of defense are the innate immune responses and the adaptive immunity, which involves B cells and T cells.

What is the role of B cells and T cells in the adaptive immune response?

B cells and T cells are recruited to fight microbes and record information about them, creating a memory of the invaders to facilitate a quicker and more effective response if the same pathogen invades again.

Why is there a risk involved in the body's natural immune response to pathogens?

The risk lies in the time it takes for the body to learn how to respond and build up defenses. A weak or young body may face serious risks if invaded by a severe pathogen.

What is the fundamental principle behind the use of vaccines?

Vaccines work on the same principles as the body's defense mechanisms, triggering the adaptive immune system without exposing the person to the full strength of the disease.

What are the two main types of traditional vaccines mentioned in the script?

The two main types are live attenuated vaccines, which contain a weakened form of the pathogen, and inactive vaccines, which contain killed pathogens.

What is the limitation of live attenuated vaccines?

Live attenuated vaccines can be difficult to make, and due to their live nature, they are not suitable for people with weaker immune systems.

What are subunit vaccines and how do they differ from live attenuated or inactive vaccines?

Subunit vaccines are made from only one part of the pathogen, the antigen, which triggers the immune response. They differ by isolating specific components of antigens, such as proteins or polysaccharides, to prompt specific immune responses.

What is the concept behind DNA vaccines and how do they work?

DNA vaccines involve isolating the genes that produce specific antigens. When injected, these genes instruct the body's cells to make the antigens, causing a strong immune response and preparing the body for future threats without containing harmful pathogen ingredients.

What potential does the development of new vaccines have for treating currently challenging diseases?

The development of new vaccines may lead to more effective treatments for invasive pathogens and could potentially enable us to treat diseases like HIV, malaria, or Ebola in the future.

Outlines

00:00

🧬 The Birth of Vaccination and Immune System Basics

This paragraph narrates the historical account of Edward Jenner's pioneering vaccination experiment in 1796, where he used cowpox virus material to inoculate an eight-year-old boy, successfully protecting him from smallpox. It delves into the immune system's function, explaining how it responds to foreign microbes with both innate and adaptive immunity. The innate immune response is characterized by common symptoms like coughing and fever, which are part of the body's defense mechanism. Adaptive immunity involves B cells and T cells that not only combat the invaders but also create a 'memory' of them for a quicker and more effective response in case of future invasions.

🛡️ Vaccines: Enhancing the Body's Adaptive Immunity

The paragraph discusses the concept of vaccines, which are designed to prepare the body's immune system in advance for potential infections. It explains how vaccines leverage the body's adaptive immune response without causing the full-blown disease. The paragraph outlines different types of vaccines: live attenuated vaccines, which use weakened pathogens; inactive vaccines, which use killed pathogens; and subunit vaccines, which contain only specific antigens. Each type of vaccine has its advantages and limitations, such as the difficulty in producing live attenuated vaccines and the shorter immunity duration of inactive vaccines. Subunit vaccines are highlighted for their ability to prompt specific immune responses by isolating components of antigens.

🧬 DNA Vaccines: A New Frontier in Immunization

This section introduces DNA vaccines as an innovative approach in vaccine development. Unlike traditional vaccines, DNA vaccines involve the use of specific genes that code for antigens. When these genes are injected into the body, they instruct the body's cells to produce the antigens, which in turn trigger a strong immune response. This method is advantageous as it includes only the necessary genetic material to stimulate immunity without the risk of causing the disease. The paragraph concludes by suggesting the potential of DNA vaccines in developing more effective treatments for challenging diseases such as HIV, malaria, and Ebola, drawing a parallel to Jenner's foundational work that propelled modern medicine.

Keywords

💡Edward Jenner

Edward Jenner was an English scientist who is known as the pioneer of the smallpox vaccine. In the script, he is credited with the first-ever vaccine development, which involved injecting material from a cowpox virus into an eight-year-old boy. This historic event is central to the video's theme of vaccination and its impact on modern medicine.

💡Cowpox virus

The cowpox virus is a virus that was used by Edward Jenner in his groundbreaking experiment. The script mentions that Jenner used material from this virus to inoculate a child against smallpox, demonstrating the concept of cross-protection in immunology. This term is key to understanding the origins of vaccination.

💡Smallpox virus

Smallpox virus was a deadly pathogen that caused severe outbreaks in the past. The script explains that Jenner's vaccine was designed to protect against this virus. The eradication of smallpox is a testament to the effectiveness of vaccines, making this term crucial to the video's narrative.

💡Innate immune response

The innate immune response is the body's first line of defense against pathogens, as described in the script. It includes symptoms like coughing, sneezing, and fever, which are the body's natural reactions to fight off infections. This concept is fundamental to understanding the immune system's role in disease prevention.

💡Adaptive immunity

Adaptive immunity is the second line of defense mentioned in the script, involving specialized cells like B cells and T cells. It is a more specific and targeted response that also creates a 'memory' of pathogens to respond more effectively in the future. This concept is central to the video's explanation of how vaccines leverage the body's immune capabilities.

💡B cells and T cells

B cells and T cells are types of white blood cells that play a critical role in the adaptive immune response, as highlighted in the script. They are responsible for recognizing and remembering pathogens, as well as orchestrating the immune response. Understanding these cells is key to grasping how vaccines work.

💡Vaccines

Vaccines are the main subject of the video script. They are biological preparations that stimulate the body's adaptive immune system to recognize and fight specific pathogens without causing the disease. The script discusses various types of vaccines and their mechanisms, making this term essential to the video's theme.

💡Live attenuated vaccines

Live attenuated vaccines are a type of vaccine mentioned in the script, made from a weakened form of the pathogen. They are capable of triggering an immune response similar to the natural infection but without causing the disease. This term is important for understanding one of the methods used to create vaccines.

💡Inactive vaccines

Inactive vaccines, as described in the script, are vaccines in which the pathogens have been killed. They cannot cause disease but still stimulate an immune response. Understanding this term helps to differentiate between the various types of vaccines and their properties.

💡Subunit vaccine

A subunit vaccine is a type of vaccine that contains only specific parts of the pathogen, called antigens, as mentioned in the script. These vaccines are designed to elicit a targeted immune response. This term is crucial for understanding the specificity and safety of some vaccines.

💡DNA vaccines

DNA vaccines represent a newer category of vaccines discussed in the script. They contain genes that code for specific antigens, which, when injected, instruct the body's cells to produce these antigens and trigger an immune response. This term is significant for illustrating the innovation and potential of future vaccines.

💡Antigens

Antigens are the components of a pathogen that trigger an immune response, as explained in the script. They are crucial for the function of subunit and DNA vaccines, which focus on these components to stimulate immunity. Understanding antigens is key to grasping how vaccines instruct the immune system.

Highlights

In 1796, Edward Jenner injected cowpox virus material into an eight-year-old boy, pioneering the first-ever vaccine.

Jenner's inoculation successfully protected the boy from the deadly smallpox virus.

The immune system's response to foreign microbes includes coughing, sneezing, inflammation, and fever.

Adaptive immunity is the body's second line of defense involving B cells and T cells.

B cells and T cells create a memory of pathogens to fight them more effectively in the future.

Vaccines leverage the body's adaptive immune system to prepare it for potential infections without causing the disease.

Live attenuated vaccines use a weakened form of the pathogen to trigger an immune response.

Inactive vaccines contain killed pathogens to elicit an immune response without causing the disease.

Subunit vaccines are made from a single antigen part of the pathogen to provoke a targeted immune response.

DNA vaccines involve injecting genes that instruct the body's cells to make specific antigens.

DNA vaccines could lead to more effective treatments for invasive pathogens.

Vaccines have the potential to prepare the immune system against severe pathogens even in those with weak immune systems.

The development of vaccines continues to be crucial for combating diseases like HIV, malaria, and Ebola.

Vaccines work by mimicking the body's natural defense mechanisms without causing the full-blown disease.

Different types of vaccines have unique methods of triggering the immune system for protection.

The success of vaccines relies on the body's ability to recognize and respond to pathogens more quickly upon subsequent exposures.

Advancements in vaccine technology may pave the way for treating currently incurable diseases.

Transcripts

In 1796, the scientist Edward Jenner

injected material from a cowpox virus into an eight-year-old boy

with a hunch that this would provide the protection needed

to save people from deadly outbreaks of the related smallpox virus.

It was a success.

The eight-year-old was inoculated against the disease

and this became the first ever vaccine.

But why did it work?

To understand how vaccines function,

we need to know how the immune system defends us against contagious diseases

in the first place.

When foreign microbes invade us,

the immune system triggers a series of responses

in an attempt to identify and remove them from our bodies.

The signs that this immune response is working

are the coughing, sneezing, inflammation and fever we experience,

which work to trap, deter and rid the body of threatening things, like bacteria.

These innate immune responses also trigger our second line of defense,

called adaptive immunity.

Special cells called B cells and T cells are recruited to fight microbes,

and also record information about them,

creating a memory of what the invaders look like,

and how best to fight them.

This know-how becomes handy

if the same pathogen invades the body again.

But despite this smart response, there's still a risk involved.

The body takes time to learn how to respond to pathogens

and to build up these defenses.

And even then,

if a body is too weak or young to fight back when it's invaded,

it might face very serious risk if the pathogen is particularly severe.

But what if we could prepare the body's immune response,

readying it before someone even got ill?

This is where vaccines come in.

Using the same principles that the body uses to defend itself,

scientists use vaccines to trigger the body's adaptive immune system,

without exposing humans to the full strength disease.

This has resulted in many vaccines, which each work uniquely,

separated into many different types.

First, we have live attenuated vaccines.

These are made of the pathogen itself but a much weaker and tamer version.

Next, we have inactive vaccines, in which the pathogens have been killed.

The weakening and inactivation in both types of vaccine

ensures that pathogens don't develop into the full blown disease.

But just like a disease, they trigger an immune response,

teaching the body to recognize an attack

by making a profile of pathogens in preparation.

The downside is that live attenuated vaccines can be difficult to make,

and because they're live and quite powerful,

people with weaker immune systems can't have them,

while inactive vaccines don't create long-lasting immunity.

Another type, the subunit vaccine,

is only made from one part of the pathogen, called an antigen,

the ingredient that actually triggers the immune response.

By even further isolating specific components of antigens,

like proteins or polysaccharides,

these vaccines can prompt specific responses.

Scientists are now building a whole new range of vaccines

called DNA vaccines.

For this variety, they isolate the very genes that make the specific antigens

the body needs to trigger its immune response to specific pathogens.

When injected into the human body,

those genes instruct cells in the body to make the antigens.

This causes a stronger immune response,

and prepares the body for any future threats,

and because the vaccine only includes specific genetic material,

it doesn't contain any other ingredients from the rest of the pathogen

that could develop into the disease and harm the patient.

If these vaccines become a success,

we might be able to build more effective treatments

for invasive pathogens in years to come.

Just like Edward Jenner's amazing discovery

spurred on modern medicine all those decades ago,

continuing the development of vaccines

might even allow us to treat diseases like HIV,

malaria,

or Ebola, one day.