Ashley Min Joo Kim is a rising freshman at the University of Pennsylvania.
Over the past few months, the proponents of universal immunization in California made rapid and momentous changes to the state’s vaccination laws. Governor Jerry Brown approved the new immunization bill, SB277, first introduced in February of this year by Senator Richard Pan, only a day after the bill was presented to him.  This bill comes in the wake of the infamous Disneyland measles outbreak this past winter, which affected hundreds of children not in California and across the nation. 
The immunization legislation that existed at the time of the outbreak (and that is in effect today) requires that schools and other similar institutions only admit students that have been vaccinated against the diseases specified by the state of California. However, the law allows immunization exemptions for “medical reasons or… [because of] personal beliefs.”  Senator Pan’s bill, SB277, “eliminate[s] the exemption from immunization based upon personal beliefs.”  Many have welcomed this bill, as a way to safeguard the health of the community. They are supported by studies that show vaccines to be effective 90% to 100% of the time, especially if the vaccinations are given at a younger age.  Many proponents of SB277 also claim that the new law will protect children who are unable to be vaccinated due to medical circumstances. This concept of associative immunization is referred to as herd immunity. In order for herd immunity to succeed in effectively immunizing those that have not been vaccinated, 90% to 95% of the population must be vaccinated.