Modeling and Simulations of Direct and Indirect Impact of Vaccines
Vaccines are among the most powerful health technologies ever invented. Nevertheless predicting their actual impact can be challenging before phase III trial, and sometimes until they have been administered to a larger population group and evaluated. The reasons are primarily four:
- Modes of action that appear to be highly effective when tested in vitro or in vivo in animals, and that appear to trigger immune response in humans, may still fail to protect vaccinated individuals against infection or disease, or impair transmission to others;
- Level and duration of protection in vaccinated individuals may vary across populations and population groups, depending on age, exposure to pathogenic and non-pathogenic microbes, and genetic factors;
- Indirect protection of non vaccinated individuals living in contact with vaccinated individuals may greatly vary depending on the structure of the contact network, and on the intensity and frequency of contacts;
- Availability, quality, and acceptance of vaccines may vary and with them the 'effective vaccine coverage', which is a key determinant of protection at the population level.
We use dynamical simulations at the population (population models) and at the individual (agent based models) level to account for variables and unknowns that may determine the actual effectiveness of a vaccine, and to predict the likely magnitude and duration of direct (i.e. in vaccinated individuals) and indirect (i.e. in non vaccinated living in contact with vaccinated individuals) effects.
To read more about our activities related to epidemiology and population health, please check the page Epidemiology and Population Health. Details on our research directions, methods, and software can be found on the Research page. For further information please contact us.