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. 2010 Nov 16;173(2):127–135. doi: 10.1093/aje/kwq347

Figure 4.

Figure 4.

Distributed maps of estimated and projected upper-bound effective reproductive number, RE(t), for 2009 A/H1N1 in the United States during the winter of 2009–2010. A, 2009 week 47–49 estimates of RE(t) (from Table 2); B, the ratio of projected 2010 week 1–3 RE(t) to 2009 week 47–49 estimates of RE(t) showing the proportional change of RE(t); C, as for B, but for projected 2010 week 4–6 RE(t); D–F, 3-week projections of upper-bound RE(t) made by using the 2009 week 47–49 estimates of susceptibility and estimates of 3-week average basic reproductive number, R0(t). Both R0(t) and the upper-bound estimates of RE(t) were made by using 2-m above-ground specific humidity, q(t), from National Center for Environmental Prediction–National Center for Atmospheric Research (NCEP-NCAR) reanalysis (2). R0(t) was calculated by using equation 4 of Shaman et al. (2) and the best-fit susceptible-infected-recovered susceptible (SIRS) parameter estimates of maximum and minimum basic reproductive number. RE(t) was calculated per equation 3. D, 2009 week 50–52 projections of RE(t); E, 2010 week 1–3 projections of RE(t); F, 2010 week 4–6 projections of RE(t).