How Do Indirect Effects Differ from Direct Effects?
Direct effects are the immediate consequences of an exposure or intervention on health outcomes. For instance, the direct effect of a vaccine is the immediate protection it provides against a disease. In contrast, indirect effects include the broader, downstream impacts. For example, when a significant portion of the population is vaccinated, it can lead to herd immunity, indirectly protecting those who are unvaccinated by reducing the overall prevalence of the disease.
