Vaccines

• What is the main topic of the video discussed in the study material?

  How vaccines work and their pros and cons
• What happens to our immune system after exposure to a pathogen?


  It generally develops immunity to that pathogen
• Why do we only catch diseases like chickenpox once?


  Because our immune system develops immunity after the first exposure
• What is the benefit of vaccines in relation to disease exposure?


  They allow us to gain immunity without catching the disease
• What do vaccines contain?

  Weakened or inactivated pathogens
• How does the body respond to the weakened pathogens in vaccines?


  It produces antibodies and develops immunity
• How many diseases are we typically vaccinated against by the time we start primary school?

  More than a dozen diseases
• What is the main pro of vaccines?


  They protect us from catching horrible diseases
• What larger impact do vaccines have on disease control?


  They help control diseases that used to be common
• What is herd immunity?


  When enough people in a population are immune to a pathogen
• How does herd immunity prevent disease spread?


  The pathogen won't have people to spread to
• What happens to a pathogen when the host overcomes the disease or dies?


  The pathogen disappears
• What are some common problems associated with vaccines?


  They don't always work and can cause bad reactions
• What is a common reaction to vaccines?


  Swelling around the injection site
• What severe reactions can vaccines cause?

  Fever or seizures
• How common are bad reactions to vaccines?


  They are pretty rare
• What is the overall conclusion about vaccines from the video?

  The pros of vaccination generally outweigh the cons