There was a whole series of dire possibilities that didn't even occur to people when the US government abandoned mandatory smallpox vaccination. In another excellent article, Gina Kolata discusses how now someone's got to make the choice about how to protect against a terrorist attack. The choice is

whether it is worth accepting a few deaths and serious injuries to protect the nation against a threat that may not materialize.

When we make choices, we're often biased, and tend not to make very good choices. When we hear stories of vaccine victims, all too often we respond with visceral fear rather than logic. Added to this is

the emotional power of the anecdote to erode a consensus � how the story of a single vaccine victim, or even one who mistakenly believed he was injured by a vaccine, can overwhelm logical arguments about risks and benefits.

Rational debate will be difficult. As usual.