Figure 3From: Transmission patterns of smallpox: systematic review of natural outbreaks in Europe and North America since World War II Initial Reproductive Rate (Median ---). Initial effective reproduction rate (initial R) in 30 post-World War II Western European and North American smallpox outbreaks by setting (Figure 3a), clinical presentation of the index case (Figure 3b), and identification of the index case with smallpox (Figure 3c).Back to article page