Potential repercussions of antiviral treatment for pandemic influenza using a seasonally forced SIR Model

When there are limited resources, control measures of an incipient influenza pandemic must be carefully considered. Because there are several months needed before mass producing vaccines to a new identified pandemic strain, antiviral drugs are often considered the first line of defense in a pandemic situation.Here we use an SIR disease model with seasonality (i.e., periodic transmission rate) to assess the efficacy of control strategies via antiviral drug treatment during an outbreak of pandemic influenza. We show that antiviral treatment can have a detrimental impact on the final size of the pandemic in some situations, which are independent of drug-resistance effects. Antiviral treatment also has the potential to increase the size of the major peak of the pandemic, and to cause it to occur earlier than it would have if treatment were not used.Our studies suggest that when a disease exhibits periodic patterns in transmission, decisions of public health policy will be particularly important as to how control measures such as drug treatment should be implemented.