A few recently published studies offered some insight into the issue of closing schools to reduce the effects of a flu epidemic.

The first problem, which hasn't been resolved, is determining the criteria for closing a school in the first place.  However, another study suggests that such closures could reduce swine flu transmission by 21%.  In this case the presumption is that reducing exposure would, of course, stall the spread of the disease.

The most telling research though came from a third paper which indicates that none of these measures may be effective unless we're prepared to keep schools closed for a minimum of 8-weeks or longer.  Basically, the point is that a quarantine is what is needed to control the spread of the disease.

After considering all three papers, it seems clear that unless we're prepared for a long-term shutdown of schools (and possibly workplaces), it is unlikely that anything can significantly reduce the transmission of an epidemic disease through the population.  This does make the case for vaccination much more compelling, since this addresses the issue at an individual level, rather than attempting to control the movement of the virus itself.

In the end, it's your immune system that has to be prepared.