The graph gives the number of varicella (chicken pox) cases between 1972 and 2011. varicella is an infectious disease caused by a virus. the disease causes rash, itching, and fever in patients. the varicella vaccine was introduced in 1995. what can you conclude about the vaccine?
a graph giving the number of varicella cases in the united states between 1972 and 2011; the varicella vaccine was introduced in 1995; graph shows a high in 1985 of 225,000 cases and a low in 2011 of about 10,000 cases
a.
it was successful in eradicating chicken pox from the united states.
b.
it had no effect on the rate of chicken pox cases in the united states.
c.
it caused a 10% decrease in the number of chicken pox cases in the united states from 1995 to 2011.
d.
it initially caused a large drop in chicken pox cases in the united states, and the rate continues to decrease.