_Policies compared_ : The policies considered are similar to Longini _et al_ . Social targeting of antivirals (TAP variant) is considered for a percentage of pupils or colleagues in an assumed proportion of the schools/workplaces with index cases. So is GTAP (here called ring prophylaxis), except it is defined as the prophylaxis of the entire population within a ring of a certain radius (5, 10 or 15km) centered on each index case. A drug‐sparing variant of ring prophylaxis is considered, where only the nearest 10‐50,000 people within 10km of an index case are given a course of antivirals. For nonpharmaceutical measures, they consider social distancing (school and workplace closure), but allow that these might have unforeseen effects by increasing household and random contact rates by 100% and 50% respectively. They also consider an area quarantine policy. Specific definitions of the two latter policies are given along with Table 7 below, which shows the results for selected values of the policy implementation levels. In this study the authors exclude vaccination.

_Assumed pharmaceutical efficacy_ : Ferguson _et al_ . (2005) assume oseltamivir efficacy for susceptibility to infection to be 30%, and efficacy for secondary prevention at 65%. Oseltamivir efficacy for infectiousness is assumed to be 60%. Over the entire course of treatment, oseltamivir reduces total infectiousness by a maximum of 28%. The assumptions reference work on resistance to oseltamivir, and other studies.

_Control objective_ : Containment: increasing the probability of eliminating a large epidemic. The ‘large’ criteria is likely to be geographical, i.e., a country‐wide epidemic.

|**Table 7:****_Effectiveness of policiesfor control in a_**<br><br><br>|**_population_**<br><br>|**_of 85_**<br> <br>**_millio_**<br><br>|**_n_**_(Fer_<br>_et_<br>_guson_<br><br><br>|_al. 20_<br>_05)_<br>|
|---|---|---|---|---|
|_P_<br>_pol_<br>_ercentage application of_<br>_icy_|_Av._<br>_co_<br>_no. of_|_0_<sup>_6_</sup>_)_<br>_urses_<br> _(1_|_li_<br>_Pro_<br>_m_<br>_b. of e_|_n_ _(%)_<br>_inatio_|
||_R_<br>_0_<sup>= 1.5</sup>|_R_<br>_0_<sup>= 1.7</sup>|_R_<br>_0_<sup>= 1.5</sup>|_R_<br>_0_<sup>= 1.7</sup>|
|**_1_**<br>s<br>. 90% TAP+90% GTAP<sup>ξ</sup>in 90% of case|≈1.8|≈2|≈92%|**0%**|
|**_2_**. Drug‐sparing GTAP<br>*|≈1.2|≈1.6|≈95%|≈75%|
|**_3_**. Drug‐sparing GTAP<sup>*</sup>, 80% quarantine<sup>**</sup>|≈0.75|≈<br>1.25|100%|≈92%|
|**_4_**<br>n<br>. Drug‐spari g GTAP<sup>*</sup>, social distancing<sup>#</sup>, 80%<br>quarantine|≈0.75|≈1.4|100%|≈99%|
|**_5_**. 90% GTAP<sup>ξ</sup>& 80% quarantine, but with a 3<br>millioncourseslimit|‐|‐|≈92%|≈80%|
|**6**<br>antine,<br>. Drug‐sparing GTAP<sup>*</sup>& 80% quar<br>but<br>witha _1_millioncourseslimit|‐|‐|≈90%|≈60%|

ξ Within a 5km radius of an index case * 50,000 courses (people) within a 10km radius of an index case # 80% reduction of movement in and out of a zone defined by merging the 5km rings around index cases ** 21‐day closure of 90% of schools and 50% of workplaces within 5km of an index case _Discussion_ : Table 7 presents a comparison of outcome measures for selected levels of implementation (mostly the median) for policies at levels of _R0_ . In their paper, the authors represent outcomes graphically, and allow for 95% confidence limits for results at a particular _R0_ and level of implementation. Therefore the ≈ sign in Table 7 represents approximation for discussion purposes.

The threshold effects of _R0_ on policy effectiveness seen in the Longini _et al._<sup>3</sup> study have intensified. A pure targeted antiviral policy (TAP and GTAP) does not provide containment at higher _R0_ . Mixed pharmaceutical plus nonpharmaceutical policies (e.g., **_4_** in Table 7) achieve full elimination at lower _R0_ , and up to 90% at _R0_ =1.9, a trend similar to Longini _et al_ . Containment with TAP+GTAP fails at lower levels of _R0_ if delays in policy initiation grow from 0 to 4 days (not shown in Table 7). It is not clear why a drug‐sparing 19