Susceptible Host: A person at elevated risk for developing an infection when exposed to an infectious agent due to changes in their immune system defenses.For example, individuals exposed to COVID-19 may not develop an active respiratory infection but can spread the virus to other susceptible hosts via sneezing.For example, infants (up to 2 years old) and older adults (aged 65 or older) are at higher risk for developing infections due to underdeveloped or weakened immune systems.Additionally, anyone with chronic medical conditions (such as diabetes) are also at higher risk of developing an infection.