Changes

The USA has mandatory vaccination according to an official CDC schedule. Enforcement is left to the states. Most states have medical and religious exemptions. Some states make it very easy to opt out of vaccines, while other states strictly enforce compliance for school attendance. The difference in vaccination rates between these states is actually very slight, and not nearly enough to affect herd immunity.   

The USA has mandatory vaccination according to an official CDC schedule. Enforcement is left to the states. Most states have medical and religious exemptions. Some states make it very easy to opt out of vaccines, while other states strictly enforce compliance for school attendance. The difference in vaccination rates between these states is actually very slight, and not nearly enough to affect herd immunity.   

Measles has been eliminated from the USA, and the USA maintains herd immunity for measles, even in states where it is easy to opt out of vaccination requirements. Occasionally a case comes in from overseas travel, but the impact is minimal and no one has died from measles in years.<ref> [http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5708a3.htm]</ref>

As of February 2008, the CDC noted that "fewer than 100 measles cases are now reported annually in the United States and virtually all of those are linked to imported cases".  The USA maintains herd immunity for measles, even in states where it is easy to opt out of vaccination requirements. Occasionally a case comes in from overseas travel, but the impact is minimal and no one has died from measles in years.<ref> [http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5708a3.htm]</ref>

== Adverse Reactions ==

== Adverse Reactions ==