What is the best option for prevention of the anthrax infection?

Vaccine and . Antibiotics. Depending on the circumstances, a person may get vaccination. If a person has been exposed, s/he may be put on prophylactic antibiotics. See the site below for more information http://www.Ncbi.Nlm.Nih.Gov/pubmedhealth/pmh0002301/.
Avoid contact. Best way to prevent individual contact is not to work in high risk occupations: dealers of exotic hides, animal researchers, veterinarians or farm workers. Very small risk of weaponized anthrax for some deployed military personnel. Vaccine (biothrax) is only available for specific at risk populations.