I'm not sure how to answer as 'cruelty' has different meanings. Some consider intention and some don't. I think it's a good idea in general to strive not to cause suffering, even in killing. I do think innocence plays a big part here, as was mentioned before. Then you throw in things like sadomasochism and other examples of enjoying cruelty that are rather common, and it's complicated further.
Yeah, no. I'd rather test positive for Covid than ever have that **** injected into me. So that would not be the "lesser cruelty" in my eyes. I think forced injections in general are unethical, outside of what's needed for emergency medical situations where the person is unconscious (for example).And sure, an act against cruelty can be cruel itself, for example it could be the lesser cruelty - such as pricking somone with a syringe containing a vaccination against Covid