The spread of measles in the United States is undoubtedly driven by insufficient vaccination among natives. But this does not mean that the vaccination rate among immigrant groups is unimportant, or that one must be "anti-immigrant" to worry about it. In fact, low vaccination rates in the United States, regrettable as they are, make it all the more important to be vigilant about what diseases may be carried across our borders. It is probably not a coincidence that the current outbreak has been traced to Disneyland, which is a common destination for international travelers.
Some advocates of mass immigration seem to regard any such concern as illegitimate, at least when it comes to immigrants from Latin America. A recent post on the Think Progress blog ridicules Rep. Mo Brooks (R-Ala.) for suggesting that the outbreak of measles has its origin south of the border. Think Progress cites 2012 data from the World Health Organization (WHO) that show the measles vaccination rate in Mexico is 99 percent — much better than the U.S. rate of 92 percent — and that vaccination rates in most Central American nations exceed the U.S. rate as well.
But how reliable are those numbers? The WHO's vaccination estimates are oddly lower in 2013 for Mexico, Guatemala, Honduras, and Panama:
Source: World Health Organization.
So is Mexico's vaccination rate 99 percent or 89 percent? Even the WHO is not sure. Estimates are "based on data and information that are of varying, and, in some instances, unknown quality." For that reason, the organization assigns a three-tier "grade of confidence" to its estimates. They are translated in the table above as high confidence (in green), medium confidence (in yellow), and low confidence (in red).
The 89 percent estimate for Mexico is apparently more reliable than the 99 percent estimate from last year, but many estimates for Central America are in the red. Low confidence means "there are no directly supporting data; or data from at least one source ... challenge the estimate." Even the U.S. vaccination estimates fail to receive the highest grade of confidence. For more perspective on these numbers, consider that the CDC warns travelers about a major measles outbreak in the Philippines — even though the WHO puts the vaccination rate in the Philippines at 90 percent.
We simply don't know enough about vaccination and disease rates in immigrant-sending countries to satisfy Americans' understandable public health concerns. The uncertainty is compounded by the fact that immigrants do not typically represent a cross-section of the sending country's population, but instead could be pulled from subpopulations that are less (or more) likely to be vaccinated than average.
Public health has always been an important immigration issue. As CIS's David North has explained, one of the primary purposes of Ellis Island was to screen immigrants for diseases. But there is no modern-day equivalent of Ellis Island for illegal immigrants who cross our border undetected. Even as illegal immigrants come "out of the shadows" to register for President Obama's administrative amnesties, there is no indication that a medical screening has been or will be part of the process. Surely it's not "anti-immigrant" to insist on one, nor is it inappropriate to worry about the broader health effects of mass immigration.