Our estimates of R 0 predict that only relatively low levels of vaccination coverage are required to eliminate rabies (;20-45%), but there is considerable variation in empirically observed levels of coverage that have successfully controlled the disease; low levels of coverage (30-50%) have been successful in some circumstances [27] , although higher levels have also failed [28] . Our analyses suggest that these inconsistencies are, in large part, a consequence of host demography. When vaccinations are carried out in pulses, births and deaths within the host population will continuously reduce the level of herd immunity attained during campaigns (Figure 4, inset) . Turnover of domestic dogs in rural Tanzania is very high (Table 3) ; therefore, annual campaigns should aim to vaccinate 60% of the dog population to maintain vaccination coverage above P crit for the duration of the interval between campaigns. When successive campaigns have achieved this, rabies incidence has declined dramatically despite high endemic levels in adjacent areas [29] . Domestic dog population turnover therefore appears to have had a marked influence on rabies dynamics that explains the variable success of vaccination efforts. The empirically derived consensus that 70% coverage is sufficient for long-term rabies elimination [30, 31] was likely reached because it is effective as a target for annual campaigns in almost all demographic settings, including those with particularly high turnover such as those we describe from Tanzania.