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.   

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" in which someone is infected during overseas travel.  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" in which someone is infected during overseas travel.  The USA maintains herd immunity for measles, even in states where it is easy to opt out of vaccination requirements.<ref> [http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5708a3.htm]</ref> Measles can be serious; according to an article in The Times, "About one in every 15 children has complications that can include meningitis, pneumonia, fits, encephalitis (swelling of the brain), blindness and brain damage."<ref>The Sunday Times, ''How the MMR scare led to the return of measles'', February 8, 2009[http://www.timesonline.co.uk/tol/life_and_style/health/article5683687.ece]</ref>  In the England and Wales, there were 1,348 cases of measles in 2008; two children died of the disease. <ref>The Sunday Times, ''MMR doctor Andrew Wakefield fixed data on autism'', by Brian Deer, February 8, 2009 [http://www.timesonline.co.uk/tol/life_and_style/health/article5683671.ece]</ref>

The CDC notes that when a measles outbreak occurs, the cost to taxpayers can be substantial.  Public health responsibilities include "identification of cases, isolation of patients and vaccination, administration of immune globulin, and voluntary quarantine of contacts who have no evidence of measles immunity...In Iowa, the public health response to one imported measles case cost approximately $150,000."<ref>Centers for Disease Control and Prevention, Morbidity and Mortality Weekly Report, ''Outbreak of Measles --- San Diego, California, January--February 2008'', February 29, 2008 [http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5708a3.htm]</ref>

The CDC notes that when a measles outbreak occurs, the cost to taxpayers can be substantial.  Public health responsibilities include "identification of cases, isolation of patients and vaccination, administration of immune globulin, and voluntary quarantine of contacts who have no evidence of measles immunity...In Iowa, the public health response to one imported measles case cost approximately $150,000."<ref>Centers for Disease Control and Prevention, Morbidity and Mortality Weekly Report, ''Outbreak of Measles --- San Diego, California, January--February 2008'', February 29, 2008 [http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5708a3.htm]</ref>