All vaccinations are tested rigorously before they are approved, and tracked afterwards  All vaccinations are tested rigorously before they are approved for use. As vaccinations represent an important and potential harmful intrusion in an individual’s body, it is very important that they are safe. This is especially clear when governments decide to make immunization obligatory; they have to be sure they administer to their citizens safe vaccinations.  Based on the increase in the number of compulsory vaccinations in different countries, many governments have also stocked up on the funding of vaccination controlling of offered immunization treatments. Such stockpiling would only occur if they were confident that the vaccines have passed through a rigorous testing process.  Furthermore, even after being approved, organizations exist, like the United States Vaccine Adverse Event Reporting System, as a center for tracking adverse events related to specific vaccines. If the events classified as serious are reported regularly for a specific vaccine, the vaccine can be subject to further study [1] .  [1] Why it is important to monitor vaccine safety, Center for disease control and Prevention,  , accessed 07/10/2011