Sono un biologo molecolare e ti spiego cosa c'è dentro i vaccini.

Summary

In this video, molecular biologist Sergio Pistoi delves into the history and science of vaccines. He explores the evolution from Edward Jenner's first smallpox vaccine to modern innovations like mRNA and viral vector vaccines, with a focus on how these vaccines protect us from diseases. Pistoi explains how vaccines work by stimulating the immune system without causing illness, highlighting the differences between live, inactivated, and subunit vaccines. He also touches on the significance of collective immunity and the ongoing technological advances in vaccine development, emphasizing the importance of global vaccination efforts to combat pandemics.

Takeaways

• 😀 Vaccination is a method to stimulate the immune system to recognize and fight specific pathogens without causing illness. It trains the immune system to create antibodies against a pathogen in a controlled way.
• 😀 Edward Jenner invented the first true vaccine in 1796, using cowpox to immunize people against smallpox. This marked the beginning of modern vaccination practices.
• 😀 The word 'vaccine' comes from the Latin word for cow, 'vacca,' in honor of Jenner's discovery using cowpox.
• 😀 Smallpox was a devastating disease, but thanks to widespread vaccination efforts, it was eradicated globally by 1980.
• 😀 There are different types of vaccines today, such as live attenuated vaccines, inactivated vaccines, subunit vaccines, viral vector vaccines, and mRNA vaccines, each using different methods to stimulate immunity.
• 😀 Live attenuated vaccines use weakened versions of the actual pathogen to induce immunity, while inactivated vaccines use dead pathogens or their components.
• 😀 Subunit vaccines, like those for HPV or Hepatitis B, only contain parts of the pathogen (like a protein), which helps stimulate immunity.
• 😀 Viral vector vaccines, such as those used for COVID-19 (AstraZeneca, Johnson & Johnson), use harmless viruses to deliver genetic material that prompts cells to produce a pathogen's protein and trigger an immune response.
• 😀 mRNA vaccines, like Pfizer and Moderna for COVID-19, deliver genetic instructions to cells to produce a protein of the pathogen, prompting an immune response without needing the pathogen itself.
• 😀 The effectiveness of a vaccine is not determined by its type (live, inactivated, etc.) but rather by how it performs in clinical trials and in real-world conditions. Vaccination efforts must be global to prevent disease spread and mutation.

Q & A

What is the main purpose of a vaccine?

The main purpose of a vaccine is to stimulate the immune system to produce antibodies against a specific pathogen without causing illness, preparing the body to fight the disease if it encounters the pathogen in the future.

How do vaccines help in providing immunity?

Vaccines introduce a 'preview' of a pathogen to the immune system, either through weakened or killed versions of the pathogen or parts of it, so the immune system can produce antibodies and 'remember' how to fight it if encountered again.

What was the historical method used before vaccines, and why was it dangerous?

Before vaccines, the method of 'variolization' was used, where material from a sick person’s pustules was injected into healthy individuals to protect them. It was dangerous because it still led to infections, and many people died from the procedure.

Who was Edward Jenner, and how did he contribute to the development of vaccines?

Edward Jenner was an English physician who created the first true vaccine in the late 1700s by using material from cowpox lesions to inoculate people, which led to immunity against smallpox, a deadly disease.

How do live attenuated vaccines work?

Live attenuated vaccines use a weakened version of the pathogen to stimulate a strong immune response. These vaccines mimic a natural infection, allowing the immune system to recognize and fight the pathogen more effectively.

What is the difference between live attenuated vaccines and inactivated vaccines?

Live attenuated vaccines use a weakened form of the pathogen, while inactivated vaccines use dead or inactivated pathogens, which can't cause disease. Inactivated vaccines generally produce a weaker immune response than live vaccines.

What is the concept of 'subunit' vaccines, and how do they work?

Subunit vaccines use pieces of the pathogen, such as proteins, instead of the whole organism. These pieces trigger the immune system to produce antibodies, offering protection without the risk of using the entire pathogen.

What is a viral vector vaccine, and how does it work?

A viral vector vaccine uses a harmless virus (often from a different species) to deliver genetic instructions to cells in the body, teaching them to produce a protein from the pathogen, which stimulates an immune response.

What is the advantage of mRNA vaccines, and how do they differ from traditional vaccines?

mRNA vaccines use messenger RNA to instruct cells to produce a protein from the pathogen, triggering an immune response. Unlike traditional vaccines, they don't use live or inactivated pathogens, and they can be updated more quickly to address new variants.

Why is collective immunity important for vaccination programs?

Collective immunity, or herd immunity, is crucial because it ensures that enough people are vaccinated to prevent the spread of a pathogen. Even individuals who are not vaccinated are protected because the disease cannot easily spread within the population.