[ColanR]

If these were internal memos among domain experts, then understanding the nuances between "100% effective" and "immune" would be expected. But when the vaccine is being sold to the general population as "100% effective" I think we're just talking about wordplay.

Those articles made some pretty strong claims, and I'm not really sure what else a layperson is expected to take away from this besides "100% I won't get covid".

> Covid-19 vaccine is 100% effective

> Researchers observed 18 Covid-19 cases among the 1,129 participants who were given a placebo, and none among the 1,131 volunteers who got the vaccine.

> Pfizer COVID Vaccine Is 100% Effective in Adolescents

> A two-dose series was 100% effective against COVID-19, which was measured between 7 days and 4 months after the second dose.

[latchkey]

You seem fixated on the layperson.

[onecommentman]

No, CNN, WebMD, etc. are fixated on the layperson because the general public is their target audience. And it is the general language of that audience that determines the proper usage of phrases like “100% effective”. You can’t unring that bell, or say after the fact that it was actually a bird song. It was journalistic malpractice.

If there actually was a confusion between the medical and common usage of the term (that I strongly doubt), the medical professionals that use “efficacy” in a different sense have the duty to correct the popular media when they misuse the language. The miscommunication lies either with the mass media itself, or jointly with the medical community. Not the audience. (And I doubt the medical community had anything to do with this. I don’t remember reading in BMJ, Lancet, NEJM, etc. anyone claiming “100% efficacy” of, well, anything ever.)

However, a more relevant linguistic issue arose within the medical community itself when using the word “case” in COVID reporting. Epidemiologists are fine with a “case” that shows no symptoms, whereas a clinician on the front lines expects to see a symptom or two before writing up a “case study”. An asymptomatic person is not a “case” to ER physicians, because there isn’t a medical symptom for which a person (at this point not a patient) has asked, or blatantly needs, diagnosis and treatment. Trolling for potential diseases a person might have (calling everyone a “case” for something) is frowned upon by medical ethics boards and insurance companies. (Pharmaceutical firms, on the other hand, just love that sort of behavior…hypochondria is quite profitable.)