Weakened or thinned. Attenuated strains of disease-causing bacteria and viruses are often used as vaccines. The weakened strains are used as vaccines because they stimulate a protective immune response while causing no disease or only mild disease in the person receiving the vaccine.
ATTENUATED
Meaning of ATTENUATED in English
NCI English Dictionary of Cancer Terms. Английский словарь раковых терминов NCI(Национальный институт злокачественных новообразований). 2012