NR 507 Week 1 Quiz: Questions and Answers with Explanation What of the following remains a significant cause of morbidity and mortality worldwide? Which statement about vaccines is true? After sexual transmission of HIV, a person can be infected yet seronegative for _____ months. Cells in _____ may act as a reservoir in which HIV can be relatively protected from antiviral drugs. Once they have penetrated the first line of defense, which microorganisms do neutrophils actively attack, engul...