i Limitations

    Our calculations have not incorporated all plausible heterogeneities. For example, personal infection control and distancing may not be adopted uniformly. Some individuals will practice it conscientiously, while others may practice it only minimally. Some plausible differential severity in infection, e.g. in the elderly, has not been accommodated.

Some aspects of the structure of the community, e.g. geographic dispersion, are not accommodated.

There are also limitations with regard to the results on AVs. They are given at the end of the next section.

    ii Further work needed

    The extent to which we have allowed for heterogeneity among individuals has been severely limited by the tight timelines. It is necessary to check the sensitivity of results to heterogeneities such as those mentioned above.

The models used here do not include the elderly as a separate class. This makes the current suite of models unsuitable for considering interventions that may differentially impact this group, such as quarantining aged care facilities. In future work we will adapt these models to assess the impact interventions targeted at the elderly.

The two forms of infectiousness function we have used, Figure 2.1, are motivated by data on current and past influenza. It seems worthwhile to perform calculations on alternatives that are guided by data from sporadic human cases of avian influenza.

    iii Contrasting the results with those for SARS

    Isolating cases and quarantining households have the greatest potential to reduce transmission when there is an appreciable time from infection until the end of infectivity. Isolating cases would be expected to be considerably more effective for SARS than for influenza, as SARS cases show a longer latent period, and are infectious for longer.

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