in their memory. Studies and research are being conducted to determine effective ways to correct misinformation in the public memory. Since the Wakefield study was released over 20 years ago, it may prove easier for newer generations to be properly educated on vaccinations. A very small percentage of people have adverse reactions to vaccines, and if there is a reaction it is often mild; these reactions do not include autism. Routes of administration A vaccine administration may be oral, by injection (intramuscular, intradermal, subcutaneous), by puncture, transdermal or intranasal. Several recent clinical trials have aimed to deliver the vaccines via mucosal surfaces to be up-taken by the common mucosal immunity system, thus avoiding the need for injections. Economics of vaccination Health is often used as one of the metrics for determining the economic prosperity of a country. This is because healthier individuals are generally better suited to contributing to the economic development of a country than the sick. There are many reasons for this. For instance, a person who is vaccinated for influenza not only protects themselves from the risk of influenza, but simultaneously also prevents themselves from infecting those around them. This leads to a healthier society, which allows individuals to be more economically productive. Children are consequently able to attend school more often and have been shown to do better academically. Similarly, adults are able to work more often, more efficiently, and more effectively. Costs and benefits On the whole, vaccinations induce a net benefit to society. Vaccines are often noted for their high Return on investment (ROI) values, especially when considering the long-term effects. Some vaccines have much higher ROI values than others. Studies have shown that the ratios of vaccination benefits to costs can differ substantially—from 27:1 for diphtheria/pertussis, to 13.5:1 for measles, 4.76:1 for varicella, and 0.68–1.1 : 1 for pneumococcal conjugate. Some governments choose to subsidize the costs of vaccines, due to some of the high ROI values attributed to vaccinations. The United States subsidizes over half of all vaccines for children, which costs between $400 and $600 each. Although most children do get vaccinated, the adult population of the USA is still below the recommended immunization levels. Many factors can be attributed to this issue. Many adults who have other health conditions are unable to be safely immunized, whereas others opt not to be immunized for the sake of private financial benefits. Many