This week's movie - "Contagion".  Pretty darn good.  Even reasonably biologically accurate.  The infectious disease weenies in the audience (assuming I wasn't the only one) would have loved the mention of R-nought (as opposed to "R-naught", which it's been written as in some reviews, and which doesn't exist in epidemiological circles).  "R-subscript-zero", or R-subscript-0, is the basic reproductive rate of diseases, representing the number of new infections a single infectious person would create if dropped into a naive (i.e. never seen the disease before) population.  The bigger this number is, the more trouble.  Measles has an R-nought in the range of 15, give or take.  Vaccination, of course, has eliminated the worry of measles in the developed world, but it still kills a lot of kids in the less developed parts of the planet (usually in combination with malnutrition, which makes it kind of hard to mount a decent immune response).  Smallpox was around 6, and the flu is around 2.

Why does anyone care?  Because you need this kind of estimate in order to figure out a decent vaccination program.  It gives you an idea of how many people need to be vaccinated in order to stop the spread of the disease.

Oh, and if you're averse to vaccination?  Well, you're a moron.  Related to Jenny McCarthy, perhaps?