  We study supercritical spatial SIR epidemics on $\mathbb{Z}^2\times
\{1,2,\ldots, N\}$, where each site in $\mathbb{Z}^2$ represents a village and
$N$ stands for the village size. We establish several key asymptotic results as
$N\to\infty$. In particular, we derive the probability that the epidemic will
last forever if the epidemic is started by one infected individual. Moreover,
conditional on that the epidemic lasts forever, we show that the epidemic
spreads out linearly in all directions and derive an explicit formula for the
spreading speed. Furthermore, we prove that the ultimate proportion of
infection converges to a number that is constant over space and find its
explicit value. An important message is that if there is no vaccination, then
the ultimate proportion of population who will be infected can be \emph{much
higher} than the vaccination proportion that is needed in order to prevent
sustained spread of the infection.
