1The infectious laughter of the children in the playground was contagious, and soon everyone was smiling.
2Is the new strain of the virus highly infectious, or can it be contained through vaccination?
3The doctor warned that the patient's condition was infectious and required immediate isolation.
4The band's infectious energy and enthusiasm on stage quickly won over the skeptical audience.
5There is growing concern that the infectious nature of the disease could lead to a widespread outbreak if not properly managed.