vaccines

• What happens to our immune system after exposure to a pathogen?

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

  Because we develop immunity after the first infection
• What would be ideal regarding exposure to pathogens?

  To gain immunity without catching the disease
• How do vaccines provide immunity?

  By using weakened or inactivated pathogens
• What do weakened pathogens in vaccines still contain?

  The same antigens as the proper pathogens
• How many diseases are we vaccinated against by primary school?

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

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

  They help control diseases that were common
• What do vaccines help prevent on a large scale?

  Big outbreaks of disease called epidemics
• What is herd immunity?

  When enough people are immune to a pathogen
• What happens to a pathogen when the host overcomes the disease?

  The pathogen disappears if no hosts remain
• What is a common problem with vaccines?

  They don't always grant full immunity
• What do we check after receiving important vaccines?

  If the vaccine has been effective
• What are some bad reactions to vaccines?

  Swelling, fevers, or seizures
• How common are severe reactions to vaccines?

  Severe reactions are super rare