Understanding childhood immunizations, their serological interpretation and vaccines - A review article

The practice of immunization dates back hundreds of years. Buddhist monks drank snake venom to confer immunity to snake bite and variolation (smearing of a skin tear with cowpox to confer immunity to smallpox) was practiced in 17th century China.
Edward Jenner is considered the founder of vaccinology in the West in 1796, after he inoculated an 8 year-old-boy with vaccinia virus (cowpox), and demonstrated immunity to smallpox. In 1798, the first smallpox vaccine was developed. Over the 18th and 19th centuries, systematic implementation of mass smallpox immunization culminated in its global eradication in 1979. Vaccination is when a vaccine is administered to you (usually by injection). Immunization is what happens in your body after you have the vaccination.
The vaccine stimulates your immune system so that it can recognize the disease and protect you from future infection (i.e., you become immune to the infection.). Immunization is a proven tool for controlling and eliminating life-threatening infectious diseases and is estimated to avert between 2 and 3 million deaths each year. It is one of the most cost-effective health investments, with proven strategies that make it accessible to even the most hard-to-reach and vulnerable populations. It has clearly defined target groups; it can be delivered effectively through outreach activities; and vaccination does not require any major lifestyle change.