Using antiviral drugs for treatment
Use of antiviral drugs for treatment may be desirable if that prevents some serious illnesses and some mortality. However, such use of antiviral drugs has only a modest effect on reducing transmission. The exception is when other interventions have brought the reproduction number down to near 1. Then the additional reduction in transmission induced by the use of AVs for treatment can be substantial.
Using antiviral drugs for prophylaxis in the general population
The indiscriminate use of antiviral drugs for non-targeted prophylaxis will deplete the stockpile prematurely with minimal reduction in transmission of the infectious disease in the community.
On the other hand, use of antiviral drugs for prophylaxis that rapidly targets likely contacts of diagnosed cases can postpone the bulk of transmission in a local epidemic substantially. Using current estimates of effectiveness, the Australian stockpile is likely to be able to postpone the peak of a local epidemic for up to one year if R0 ≤ 2 and the distribution of AVs is able to rapidly target approximately 50% of contacts. Broadly speaking, if 80% of contacts can be traced, a delay of a year is possible for R0 ≤ 2.5.
However a strategy of using AVs for prophylaxis that targets individuals who are likely to have been exposed requires drugs to be dispensed rapidly to community members in increasing quantities, to the extent that this strategy may be difficult to sustain.