When a new viral infection appears in a population, scientists usually try to develop a vaccine against the virus. Which substances would most likely be contained in the new vaccine? A. live bacteria that ingest virusesB. white blood cells from an infected individualC. weakened viruses associated with the infectionD. a variety of microbes that will attack the virus

Answer: option C) weakened viruses associated with the infection

Explanation:

A vaccine is a derived from a disease-causing organism, and administed to uninfected people in order to induce the release of antibodies and set up immunity against such disease.

Therefore, weakened viruses associated with the infection, is used by scientists to develop vaccine.

Option C is the answer