AndyTheBear wrote: “A product that produces immunity therefore protecting the body from the disease.” and “I am perfectly happy to keep the traditional definition rather than substituting my own.”
You’re ignoring the fact that there are no vaccines that fit that definition. Every vaccine in existance has ‘breakthrough infections’. Therefore, no vaccine can produce immunity. A vaccine can only produce degrees of immunity, never total immunity. Hence the reason for changing the definition.
For example, the smallpox vaccine has been effective in preventing smallpox infection in 95% of those vaccinated.
Here’s a personal experience. When I was in grade school, every child had to be vaccinated against small pox. Every vaccination had to ‘take’, you had to get a scab at the vaccination point or repeat the vaccination.
I had to take the vaccination, IIRC, at least three, maybe four times, before it took.
IOW, the small pox vaccine did not provide any degree of immunity for me until the third or fourth attempt. Was it a vaccine the first three times? Of course, it was. Whether it ‘toke’ or not didn’t determine if it was a vacccine. It only determined if I had some degree of immunity. I could still get small pox after it took but the chances were significantly decreased.
BTW, even if you do get a degree of immunity from the small pox vaccine, that ‘immunity’ only last three to five years.
We have been over this. The 100% clause you added was not part of the definition.
For example, the smallpox vaccine has been effective in preventing smallpox infection in 95% of those vaccinated.
Ok, so why does that mean it does not fit this definition:
A product that produces immunity therefore protecting the body from the disease
You seem to be reading this definition as if it said:
A product that produces immunity therefore always protecting the body from the disease in 100% of the cases where the vaccine is administered. [The italics parts are your modifications]
If a vaccine produces immunity in 95% of people yet fails to produce immunity in 5% of people then the vaccine certainly qualifies as a "product that produces immunity". Just as a can opener is a tool that opens cans even if there are sometimes cans that it fails to operate well on.
Vitamin C and herbal tea and what not might "stimulate the immune system"...but they are not vaccines because they never give one immunity to a specific pathogen by triggering the targeted ability of the body to fight it like vaccines do.