Smallpox
was an infectious disease caused by one of two viruses, Variola
major and Variola minor. It is estimated that smallpox was responsible for 300-500 million deaths
worldwide. The last naturally occurring case was diagnosed in October 1977 and the World Health
Organization (WHO) certified the global eradication (elimination) of the disease in 1980. This was
accomplished by the creation of a vaccine by Edward Jenner in 1796. This vaccine was the first successful
vaccine to be developed.
What part of the Chain of Infection was broken by the development of the Smallpox vaccine?

A92-year-old man with a 45-year history of chronic obstructive pulmonary disease is intubated in the icu because of a bout of viral pneumonia that fails to improve after 72 hours of antibiotics. although the inspired fraction of oxygen is 100%, the patient's po2 remains at 57 mmhg. positive-end expiratory pressure (peep) is added to allow the inspired fraction of oxygen. twelve hours after the introduction of peep the patient suddenly become hypotensive. at the same time, his oxygen saturation drops from 92% to 61%. on physical examination, his bp is 80/50 mmhg and his pulse is 124/min. he has distended neck veins and distant heart sounds. which of the following would also most likely be seen on this patient's physical examination? - absence of breath sounds in the right hemithorax- high amplitude carotid artery upstroke- a pleural friction rub- pulsus alternans- splenomegaly