Schafer is arguing for a precautionary-principle approach:  why would you take the chance of exposing a lot of people to a vaccine too new to allow its long-term effects to be known perfectly?  Especially, we might add, when the flu outbreak you are confronting is very mild, thus far?

Not everyone finds this satisfying, though.  In fact, some people feel there’s a duty to protect the public against the eventuality of widespread virulent flu. (Two facts should trouble this argument:  the historical fact that such a flu outbreak has happened exactly once in history, and the ancillary fact that, even in 1918, before flu immunization existed, the outbreak spared over 99% of the American public. But they don’t.  We’ll ignore them for now, just as most people do.).

Of course, if you really think there’s a duty to protect then you make immunization mandatory.  There’s precedent, and it’s been upheld by the nation’s highest court of law — in Jacobson v. Massachusetts (1905).  Justice Harlan, writing for the majority, held that the state of Massachusetts was within its rights to require Henning Jacobson to undergo smallpox vaccination when an outbreak threatened the city of Cambridge, and to fine him $5 for his refusal to be immunized.

The Jacobson case is taught in schools of public health as a prime assertion of the police power, i.e., the right of states to make laws to protect the public’s health.  And to validate the reach of such laws, even to mild intrusions on individual liberty. Harlan writes that “the liberty secured by the Constitution of the United States to every person within its jurisdiction does not import an absolute right in each person to be, at all times and in all circumstances, wholly freed from restraint.”

But the nuances of Justice Harlan’s decision are instructive.  He made the point that the state’s legislature deemed smallpox vaccination to be effective and of minimal harm, and allowed the city to require vaccination only when a properly constituted board of health determined that that was necessary for public health.  In other words, the police power allows a state to limit liberty in the name of public health, but not for just any excuse, by any means, or without considering consequences.

And, we note, Harlan’s decision hinged on the legislative power.  That is, mandatory vaccination wasn’t  okay just because a board of health had said so; it was okay because the legislature had passed a law allowing the board to make such a decision, and the law was reasonable and sound.

Harlan’s basic standard was the “necessity of the case.”   Cambridge could make Mr. Jacobson undergo vaccination because the state law gave the board of health the power to decide when universal vaccination was necessary, in view of the situation.  And the board had looked at the situation, and decided that vaccination was indeed necessary

What should we make of that today?  In view of the current swine flu situation, should we then stand with Schafer, and argue that the most basic of the tenets — necessity — on which the police power is predicated has not yet been met?

Or should we say that the potential for a severe flu outbreak — a possibility not yet realized but, well, possible — creates a necessity to vaccinate?

Or is Jacobson simply out of date?