Editing Immunization (section)

=== Socially optimal outcome ===
Having private marginal benefits lower than social marginal benefits will always lead to an under-consumption of any good. The size of the disparity is determined by the value that society places on each different immunization. Many times, immunizations do not reach a socially optimum quantity high enough to eradicate the antigen. Instead, they reach a social quantity that allows for an optimal amount of sick individuals. Most of the commonly immunized diseases in the United States still see a small presence with occasional larger outbreaks. [[Measles]] is a good example of a disease whose social optimum leaves enough room for outbreaks in the United States that often lead to the deaths of a handful of individuals.<ref>{{Cite journal|last1=Cook|first1=Joseph|last2=Jeuland|first2=Marc|last3=Maskery|first3=Brian|last4=Lauria |first4=Donald|last5=Sur|first5=Dipika|last6=Clemens|first6=John |last7=Whittington |first7=Dale |date=2009 |title=Using private demand studies to calculate socially optimal vaccine subsidies in developing countries |journal=Journal of Policy Analysis and Management |volume=28|issue=1|pages=6–28 |issn=0276-8739 |pmid=19090047|doi=10.1002/pam.20401}}</ref>
[[File:Eradicated Immunization Shift.png|thumb|Immunization B has a social marginal benefit large enough to bring Q1 to Q(e), the quantity at which eradication occurs.]]
There are also examples of illnesses so dangerous that the social optimum ended with the eradication of the virus, such as [[smallpox]]. In these cases, the social marginal benefit is so large that society is willing to pay the cost to reach a level of immunization that makes the spread and survival of the disease impossible.

Despite the severity of certain illnesses, the cost of immunization versus the social marginal benefit means that total eradication is not always the end goal of immunization. Though it is hard to tell exactly where the socially optimal outcome is, we know that it is not the eradication of all disease for which an immunization exists.