It depends on what sort of responses you are referring to. Do you mean immunological/physiological activity and responses? Or do you mean potential behavioral responses.? In the case of behavioral responses, I assume you might be interested in how contact patterns and transmission opportunities might change in infected populations. I think that social networks analysis is a fairly sensitive framework in which to analyze contact patterns before and after virus infection. Social networks would be especially sensitive to group- or population-level changes in inter-individual connectivity patterns in populations that are experiencing epidemics. However, they can also be used to look at changes contact patterns from an individual standpoint.

See Zitzow et al. J.Virol. 76:4420-4429 (2002). We looked at ferret lethargy and response following influenza infection if this is what you are looking for.

Thanks Thomas! So I presume this is the 'gold standard' for measuring activity or are there any other methods?

depending what you are looking for. there are several clinical parameters you can look at. You can contact me privately by e-mail [email protected] and we can discuss other possible parameters.