from SARS, a blanket ban on flights from certain regions, incrementally updated based on new information<sup>49</sup> , could indefinitely delay importation of infectives. An airport‐based quarantine and antiviral prophylaxis policy (as planned at airports like LAX<sup>50</sup> ), could supplement this, targeting any initially asymptomatic travelers detected en route and those they potentially exposed. It can be recalled that of the 29 SARS cases in the US (plus 137 suspect and 19 probable), all imported, there were no reports of secondary transmission<sup>51</sup> . ‘Intelligent border controls’ may _contain_ the US epidemic, i.e., minimize the attack rate.

Second, even if an intelligent border control policy, supplemented by airport‐based quarantine/prophylaxis plus movement restrictions only delays the outbreaks, this delay is valuable for pandemic vaccine policies. This is considered explicitly in Germann _et al._ below. The delay may also help healthcare facilities better prepare for the surge in demand that is associated with the peak (if the peak itself cannot be reduced). This is a crucial consideration in actual prevention of severe illness and mortality. In Table 8, 99.9% effective border control (policy **_3_** ) – given a homogenous SEIR transmission model for ROW – obtained a delay of 50 days in the US peak. In the context of a heterogeneous ROW transmission scenario, this delay may be larger and applied to the first instance of secondary cases rather than the peak. Even a 50 day window is valuable for the development and deployment of a pandemic vaccine, for which manufacturers no longer solely rely on egg‐based production. As available, this vaccine may be administered to passengers, airport and healthcare workers, and other potential exposures, which may minimize the in‐country case attack rate (see policy **_18_** in Table 8).

# 4. **Germann** **_et al._ (2006)**<sup>38</sup> : The United States

_Policies compared_ : The policies compared here are similar to Longini _et al._ and Ferguson _et al._ (2006). The model derives from the former. For an assumed percentage of true index cases (excludes false positives), social targeting of antivirals (TAP variant) is considered at different levels for their preschool, school, and work contacts, as relevant. It is assumed a fixed _60% of cases_ and their contacts can always be targeted with antiviral, the constraint being stockpile size. Social distancing is considered – mainly the closure of schools, including preschool and play groups. In addition, movement restrictions are considered. The authors consider a ‘dynamic mass vaccination’ policy which uses both pre‐ pandemic and pandemic vaccines as they become available, with distribution schemes either random across the eligible population or prioritizing children. A one‐dose policy allows the vaccination of twice as many people, assumed sufficient for achieving efficacy levels for a pre‐pandemic vaccine. A two‐dose policy confers maximum protection for a well‐matched pandemic vaccine. Specifics are given wit Table 9 below. h _Assumed pharmaceutical efficacy_ : Oseltamivir efficacy and pre‐pandemic vaccine efficacy are as in Longini _et al_ . For an assumed _pandemic_ vaccine, VES=0.7 (0.5 for those older than 65), and VEI=0.8, more optimistic than Ferguson _et al._ (2006). Two doses of the pandemic vaccine and one ose for the red p ‐pandemic vaccine are assumed to be required.

_Control objective_ : Mitigation, as in Ferguson _et al._ (2006), with flavors of containment. In their discussion, the authors suggest policies to slow the spread within the US (delay the epidemic peak) such that mitigation policies can reduce total morbidity.

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