For example, influenza and polio vaccines provide protection against three types of viruses while some bacterial vaccines such as pneumococcal vaccines protect against approximately twenty-three different serotypes of Streptococcus pneumoniae. In addition to incorporating antigens into vaccines, they are also formulated with solvents (such as water/saline), preservatives and adjuvants. All these components are collectively referred to as excipients. They improve the quality and potency of vaccines during their shelf life. Health authorities have attributed the decline in disease to the impact of vaccines around the world, while assuring people of their safety and effectiveness. However, these hypotheses have also been discredited by government statistics and studies published by credible researchers around the world. Studies show that there was a significant decrease in the number of infectious diseases decades before the onset of the masses