Final answer:
Pneumonia is the severe infection caused by Adenovirus, which can also cause other illnesses like viral conjunctivitis. It is among several viral agents capable of leading to pneumonia, and can pose a high risk for children and the elderly.
Step-by-step explanation:
The severe infection caused by Adenovirus is pneumonia. Adenoviruses are one of the viral agents that can cause pneumonia, alongside influenza viruses, parainfluenza viruses, respiratory syncytial viruses, and SARS coronavirus. Unlike influenza, adenoviruses can also cause other issues such as viral conjunctivitis but are not responsible for illnesses such as malaria or dengue, which are caused by different pathogens.
Pneumonia resulting from adenovirus can be particularly serious in children and the elderly. Although viruses like influenza contribute to a greater number of pneumonia cases, adenovirus remains a significant cause of viral pneumonia.