Here is another article of many I’ve seen that that uses “efficacy” and/or “effectiveness” to mean “sterilizing immunity.”
The actual researchers cited don’t quite make that mistake, but they also don’t seem all that clear on the difference, either.
Efficacy/Effectiveness: the treatment has some (positive) effect on the course of the disease. For instance, does it prevent hospitalization? Reduce symptoms? Reduce death rates? Reduce sequelae? Reduce viral load? Reduce the duration of sickness? Etc.
Sterilizing Immunity: Does the treatment prevent infection altogether?
These are NOT the same thing. Therefore, nearly all of these panicked articles (and lib tweets) stating that the vaccines are no longer effective are completely wrong because that’s not actually what any of the data indicates.