Like I had written, my second paragraph was on topics not covered in the article. The definitions - three of them - are from the CDC.
1. Prior to 2015 (or 2016) their definition of vaccine was: "Injection of a killed or weakened infectious organism in order to *prevent* the disease."
2. From 2015-2021, their definition was: "The act of introducing a vaccine into the body to *produce immunity* to a specific disease."
3. In seeming anticipation of Biden's speech, the CDC changed the definition of "vaccination" to: "The act of introducing a vaccine into the body to *produce protection* from a specific disease."
Yes, I know the site above had some hooey. It also had a lot of good material. That is the nature of the beast called the Internet, which is why I said to spit out the bones. On Baptist Board here I see the same thing. There are a number of posters here - some in this very thread - who post things that I strongly disagree with - and then they post things that are totally spot on. I think it is unwise dis a site, or a person, because of obvious bones.
I do not know why the change.
"The act of introducing a vaccine into the body to *produce immunity* to a specific disease" applies to the covid vaccine.
It is no different from the flu vaccine...or the measles vaccine...or the pneumonia vaccine...(the list goes on).
If you get the measles vaccine you can still get the measles. If you get the pneumonia vaccine you can still get pneumonia (pneumonia is actually a possible side effect).
While sterilizing immunity is always the goal, this goal is rarely met.
The covid vacvine provides functional immunity. Just like you can get a flu vaccine and still due of the flu, the goal is to give the body some protection to fight a virus.
The covid vaccines do provide functional immunity to a specific disease (and the vaccination introduces the vaccine to the body). So the definition has not changed.
My guess would be the CDC changed the language because there was so much misinformation out there. Some do not realize that immunity does not necessarily mean you cannot get the disease as they think "sterilizing immunity".
But as far as I know we have not come up with vaccines that provide that type of immunity on a long time...they ate fairly rare (I think the Chickenpox vaccine provides sterilizing immunity...but I could be wrong).
I get changing the language in 2015 or 2016 (ModeRNA Technologies had been well in the process of mRNA vaccines....they developed 24 but were not approved ...were unnecessary, actually, as vaccines already existed).