Vaccination - Fighting Disease

• Vaccination - protects from future infections
• When you're infected with a new pathogen, it takes your white blood cells a few days to learn how to deal with it. But by that time, you can be pretty ill
• Vaccinations involve injecting small amounts of dead or inactive pathogens. These carry antigens, which cause your body to produce antibodies to attack them - even though the pathogen is harmless. E.g. the MMR vaccine contains weakened versions of the viruses that cause measles, mumps and rubella (german measles) all in one vaccine
• If live pathogens of the same type appear after a vaccine, the white blood cells can rapidly mass-produce antibodies to kill off the pathogen
• Pros of vaccination

  • Vaccines have helped control lots of communicable diseases that were once common in the UK (e.g. polio). Smallpox so longer occurs at all, and polio infections have fallen by 99%
  • Big outbreaks of disease - called epidemics - can be prevented if a large percentage of the population is vaccinated. That way, even the people who aren't vaccinated are unlikely to catch the disease because there are fewer people able to pass it on. But if a significant number of people aren't vaccinated, the disease can spread quickly through them and lots of people will be ill at the same time
• Cons of vaccination

  • Vaccines don't always work - sometimes they don't give you immunity
  • You can sometimes have a bad reaction to a vaccine (e.g. swelling, or maybe fever or seizures). But bad reactions are very rare