Attenuate
Attenuate (verb) /əˈten.ju.eɪt/
to make something weaker, smaller or less effective – weaken – lessen – reduce – decrease – diminish – mitigate – assuage – calm – soothe – lighten:
The polio vaccine is manufactured by attenuating the virus to arouse the immune system so that the body would be immunized against the malicious virus.
antonym: intensify
Adjective: attenuated
