Vaccines are certain types of preparations that are administered in patients to establish immunity to a certain disease. Edward Jenner is namely the "father of vaccines," as he was the first person in history to use the word "vacca," which in Latin means "of cows." Jenner basically inoculated cowpox to humans to protect them against smallpox. The test ran successfully and eventually Louis Pasteur, who is famously known for chicken cholera and inducing the disease in chickens, and other scientists replicated this vaccine administration using other forms of it. Although the disease of smallpox was first to be prevented through inoculation, stimulating disease resistance, and vaccination, India, China, and Turks experienced their own cultural ways of immunizing against diseases long before the inoculation of cowpox to prevent smallpox.

Vaccines can be formed in four traditional ways. The first is the inactivated vaccine, which are heat-killed virulent micro-organisms. These are short lived and require booster shots. The second type of vaccine is the live attenuated, where micro-organisms are kept at such environment where there virulent properties are disabled. These elicit a better immunological response. The third type of toxoids, which are basically the inactivated illness causing toxic components gathered from the micro-organisms containing them. The last type of vaccine would be what is called a subunit, a fragment of the micro-organism that can actually cause an illness, such as taking the surface proteins of the virus and utilizing that in the form of a vaccine.

A vaccine that is administered almost yearly, as preferred by different individuals, is the flu vaccine. Children usually are administered with the inactivated form of the vaccine, while adults are given the live attenuated vaccine. The flu, which is caused by influenza virus, kills approximately 30,000 people every year in the United States. This influenza virus has a high mutability rate, so a flu vaccine that is developed can only be administered for that year and the following year, the vaccine is altered to satisfy the changes done by the virus itself and so patients can show a good immune response to it.

People who consider taking the flu shot every year are those who are well over the age of 65, patients who have chronic lung, hear, and liver diseases, patients who have been under such medications and steroids that are likely to lower their immune status or suppress the immune system, women who are pregnant during the flu season, children of 6 to 23 months of age, and also anyone employed in a healthcare environment. Symptoms that are likely to occur in patients with flu include headache, coughing, sneezing, runny nose, fever, and fatigue. The efficacy of this flu vaccine can vary from patients to patients depending on their health status. In healthy children, efficacy can exceed 80%, whereas in adults efficacy can exceed 87%. In essence, it is recommended that the flu vaccine be given to candidates with the mentioned symptoms every year to prevent suffering.

Another common vaccine almost everyone gets during their early years of life is the tetanus and diphtheria vaccine. This vaccine is a toxoid vaccine. Tetanus is known as lockjaw and can cause painful muscle spasms, which may lead to a patient's not being able to open his or her mouth. Diphtheria is also a severe bacteria causing disease, which infects a person's bronchial parts and can coat airway passages with mucus, which will eventually lead to breathing and heart failure and can be fatal. This Td vaccine is usually administered in children during their pre-elementary years, and so is recommended for everyone of age 7 and older. The vaccine should be given at least three times in a person's lifetime. After the third dose, it is necessary to get an additional dose every ten years throughout a person's life. In most cases these the vaccine is combined for both tetanus and diphtheria. The efficacy of the Td vaccine is 92% in adults and children combined.