Which of the following developments in vaccines occurred most recently?
A. A vaccine using weakened viruses is developed to combat polio.
B. A vaccine against tuberculosis is developed.
C. A vaccine against hepatitis B gains approval from the government.
D. A vaccine against anthrax is developed.
The correct answer here is C - out of the developments listed, the most
recent development in the use of vaccines was the approval from the
government of a vaccine that can be used against Hepatitis B. This
happened relatively recently, in 1981.
