Pros and cons of vaccinia immunization.
D002487:Centers for Disease Control and Prevention, U.S.; D006801:Humans; D007757:Laboratory Infection / Q000517:prevention & control*; D009784:Occupational Diseases / Q000517:prevention & control*; D014481:United States; D014611:Vaccination; D014615:Vaccinia / Q000517:prevention & control*