**COST AND COST­EFFECTIVENESS OF POLICIES**

_Direct costs_ : The direct cost of vaccine and antigen production/procurement and distribution for the overall health sector could be estimated for different stockpile and coverage scenarios, though rigorous studies of these costs are yet to be initiated. The affordability of large‐scale vaccination and antiviral prophylaxis policies remains out of the reach of many developing nations. These costs and potential financing mechanisms require urgent research given the conclusions from the studies reviewed so far.

For NPIs, it is unclear what the direct costs should include: social, economic, and resource costs will all be incurred. For the purposes of this review, the economic costs of NPIs due to reduced demand or due to workforce disruptions (absenteeism and productivity loss due to telecommuting where this occurs) will be considered _indirect_ costs. Direct costs to the local and central public health systems of enforcing case isolation, contact tracing, movement restrictions and social distancing may be very large if these continue for long and occur in large cities. As noted by Wu _et al.,_ when a quarantine policy is selectively enforced for the households of cases and their contacts, the local authorities may have to ensure a supply of essential supplies for the quarantine to be ethical. Also, the disruption to the normal routine of people has a social cost which is difficult to compute. Such cost issues are a prime factor leading the DHHS/CDC plan to be circumspect about the recommended NPIs at different forecast levels of severity<sup>66</sup> . NPIs would be instituted in an actual pandemic regardless of such recommendations. The DHHS/CDC plan institutes centralized coordination which can reduce social costs. However, severity is difficult to predict in a way meaningful to public health plan activation, and the cost of any mistakes in terms of an inefficiently contained/mitigated epidemic with higher illnesses and deaths would be worse. Hence, the results of the modeling studies reviewed so far on the effectiveness of policies at different levels of transmissibility and feasibility are appropriate starting points for taking decisions based on the local context.

_Indirect costs_ : The indirect costs emerge from disruptions of domestic economic activity from the NPIs in the intervention scenario, as well as the reduction in international travel and business due to IATR. The costs of IATR were estimated by Epstein _et al._ for the US _and_ found to be lower than previously assumed. The per annum cost of major IATR is in the vicinity of 0.8% of GNP, vs. a potential reduction in the overall caseload reduction of about 45 million cases in urban areas in their model. Whether this loss in GDP is low from a policy standpoint is a cost‐effectiveness question. Such questions are controversial where it answers would require analysts to value the mitigated morbidity and mortality and the long‐term economic benefits therein. The latter estimates are available from other studies<sup>8</sup> which have been reviewed extensively elsewhere. Costs of NPI related reduction in demand in a city with social distancing or quarantines have been estimated as well in prospective economic modeling. The experience from SARS, where there was a quarterly reduction in the demand for services and in travel/hospitality industries in the affected cities (Hong Kong, Taipei, Beijing) are the basis for such estimates. Some of the estimates from outbreaks in locations where social distancing and/or quarantines were instituted are reported in Table 14.

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