However it can take some time dfor the immune system to create a particular antibody the first time to protect against an infection and hence we will often see symptoms of the illness before getting better. The last type of white blood cell, T-lymphocytes is used to attack the already-infected cells to stop any spreading of the disease to the rest of the body. After the illness has passed, some of these T-lymphocytes cells are kept in the body as memory cells (5) (9). Therefore, the next time our body encounters the same disease, the immune system will remember the specific type of substance needed to fight it and be able to attack it straight away. As a result, we only then live to see symptoms of many diseases only once in our lifetime. Because of the fact that many diseases can be dangerous or even deadly, becoming infected once can still do a lot of harm to the body. Vaccination are sealed to straighten the immune of system, infection of the real disease to prevent symptoms. Although there are many different types of vaccinations, they are after all made containing a weakened version of organism or pathogens which can be considered a virus or bacteria. The pathogen can be grown in cell tissues for mass production and it is at this stage, that pathogens must be weakened so that it doesn't cause the symptoms of the disease itself in people with healthy immune systems. There are a few techniques needed to do this. The pathogen can be given repeatedly and a weaker but still live version is selected which is called 'attenuating' (3) (6) or the toxin that the pathogen produces can be inactivated. Other techniques are still used to create vaccines for specific types of bacteria and depending on the diverse it causes and how it attacks cells and the responses triggered from the immune system. Another option is to take the section of the pathogen that causes an immune response, in order to create the vaccination itself.