What is vaccination?

Your immune system works very hard to make sure you stay healthy every day.  Even if a microbe gets past all of your defences and makes you sick, you know that if that microbe tries to invade again, your body will be ready.  Your body makes antibodies that for each microbe that invades (even if it doesn’t make you sick) and these patrol your body so they can be ready if that microbe tries to invade you again!

Sometimes microbes can make a person so sick, that they may not survive or, if they do, they may have lots of serious problems for the rest of their lives.  Other microbes are very contagious - they pass from one person to the next person very quickly.  If lots of people get sick at once, there would be nobody left to look after them!  The best protection against these is to build up your body’s defences and be prepared.  But how does your body know what microbe to look for if it has never seen it?  The answer is vaccination!

Vaccination sounds scary but it really isn’t!  Being vaccinated means that the doctor will give you a tiny piece of a particular microbe that is dead, so that is safe.  Vaccines won’t make you sick but it shows your body enough microbe to make sure your immune system would recognise it if it saw it again.  Your body makes antibodies to the vaccine and you are then protected if that microbe ever tries to get past your first line of defence again! 

Once you are vaccinated, you are immune to the microbe you have been vaccinated against.  You have to be vaccinated for each new microbe you need to become immune to, but sometimes a couple of vaccines are mixed together so you can do a couple at once!  Usually, when you are immune to a microbe, if it invades your body again you won’t get sick.  Every so often though, a microbe that you have been vaccinated against will invade your body and make you a little sick.  It is better though than having no defences because you are sick for a shorter time and you won’t feel as bad.

The first person to use the word vaccination was Dr Edward Jenner, who lived in England during the late 18th and early 19th centuries (from 1749 to 1823.  That’s close to 200 years ago!!).  This was a time when a disease called smallpox killed a lot of people and left others who survive with terrible scars.  Jenner saw that milkmaids (girls who milked cows) got a very mild form of the disease called cowpox, but, although the milkmaids got blisters, they didn’t get very sick.  More importantly, these milkmaids did not get smallpox, they were protected from it. 

In 1796, Jenner tested his idea by giving a young boy called James Phipps some of the pus in a cowpox blister from the hand of a milkmaid called Sarah Nelmes who had caught cowpox from a cow called Blossom!  Although James Phipps felt a little sick, he did not get smallpox, he was immune.  This was amazing because Jenner did not have all of the information and knowledge scientists have today to test out his ideas.  On his side though, scientists today cannot test out their ideas on humans! 

It took quite a while for other doctors to agree that vaccination worked – it wasn’t until 1840 that vaccination was accepted by everyone!  In 1980, the World Health Organisation declared that smallpox had been wiped out worldwide, the first disease in history to be completely conquered by humans!  To make sure that smallpox doesn’t come back though, everybody needs to be vaccinated. 

Vaccination is now a common type of disease prevention and something done very quickly by your doctor.  There are lots of diseases that you are vaccinated against when you are young like measles, mumps, rubella and polio.  If you travel abroad to countries where there are diseases and microbes that you don’t normally see in your own country remember to visit your doctor to see if you need vaccinations for these diseases and microbes.  Remember – prevention is better than cure!