In order for vaccines to protect a population from a pathogen:
a. most of the population must be vaccinated
b. no one in the population can have the disease
c. only a few people need to be vaccinated
d. everyone in the population must have the disease

The potential to eradicate preventable diseases in the future depends on other societal factors that influence coordination and deployment of global health resources. for example, 70 confirmed cases of circulating vaccinederived poliovirus type 2 (cvdpv2) were reported syria, which is embroiled in war. where else are similar societal challenges preventing the eradication of polio? uzbekistan. nigeria. pakistan. a and c. b and c.