If by stopping the illness, you mean stopping the manifestation of symptoms from the infection, that is correct.
and even when those who are vaccinated are exposed to the disease, they will either not be contagious at all or will be so for a much shorter time and generally with a milder form of the disease.
That is conventional myth. A vaccination only increases immunity in the recipient. It does NOT create some magic barrier that prevents the virus from entering a host or likewise prevent the virus from being transferred from host to host.
If you believe otherwise, then I guess you believe it's not necessary for health care workers to practice hand hygiene, since once they're vaccinated they no longer are contagious. Is that your contention?
If you mean to say and believe that the flu vaccine only prevents symptoms, no - that’s not correct. Most vaccinations, the flu vaccination for example, gives the person immunity so they do not “catch”, i.e. become infected with the virus even when they are exposed to it. If the flu virus enters the vaccinated person’s body, the antibodies in the vaccinated person’s body that were created/stimulated by the vaccine kills the live virus and that’s why the vaccinated person does not get sick and therefore does not manifest symptoms and therefore does not transmit the virus. If they do not get sick, they are not shedding live virus that can infect other people. You are completely incorrect that the flu vaccine merely prevents flu symptoms.
That is conventional myth. A vaccination only increases immunity in the recipient. It does NOT create some magic barrier that prevents the virus from entering a host or likewise prevent the virus from being transferred from host to host.
Flu viruses and many other viruses are spread mainly by droplets made when infected people cough or sneeze, wipe their runny noses or eyes or even talk because being sick, they are shedding live virus through mucus secretions. These droplets from infected people land in the mouths or noses of people who are nearby. It is true that the flu and other viruses can also be spread by touching a surface or object that has live flu virus on it and then touching their own mouth, eyes or possibly their nose but this is actually not the main and most common vector for spreading the disease because viruses typically lives for a relatively short period of time outside the body (anywhere from a few minutes up to, under the right conditions, on some types of surfaces and in environments with warm temperatures and high humidity, several hours), so that does not make frequent hand washing unnecessary or a waste of time.
So in a way you are correct that a vaccinated person “can” spread the flu by touching a surface that has live flu virus on it and then immediately touching another surface that an unvaccinated person immediately touches and in turn touches their mouth, nose or eyes (mucus membranes), but you are not correct in your assumption of what’s really happening. In that case the vaccinated person is transmitting flu, not likely from any live virus in their own body but from an infected person to a non-vaccinated person via a surface with virus on it. But again this is, contrary to what many believe not the most common why to catch the flu. You are much more likely to catch the flu by being close to someone who is actually infected (sick) when they sneeze or cough or shake your hand after wiping their nose or sneezing in their hands. While not impossible, it is very unlikely to catch the flu from someone who has been vaccinated, assuming that the vaccination worked (and vaccinations are not always 100% effective in all people), or that the vaccinated person isn’t exposed to the flu during the two weeks or so that it takes for immunity to build or that they’ve contracted some virus that that year’s flu shot does not cover or from a common cold virus. It is theoretically possible that a vaccinated person could have live flu virus living in their nasal passages for a very short period of time and if they sneeze, say because of an allergy or from dust for example, they “could” spread that live virus to another person but again, this is unlikely and would be very rare and that would not be because the vaccinated person is “infected”.
If you believe otherwise, then I guess you believe it's not necessary for health care workers to practice hand hygiene, since once they're vaccinated they no longer are contagious. Is that your contention?
No. Not at all. In a hospital setting, with doctors, nurses and other health care workers going from one patient to the next, even if vaccinated, they would and definitely should practice “hand hygiene” i.e. frequent hand washing and or the use of hand sanitizers because in that setting the hand to hand transmission of live virus is more likely not to mention preventing the spread of a plethora of bacteria. But that’s not because the vaccinated person is “contagious”. Frequent hand washing is a good idea for many reasons for everyone, at all times of the year, especially when in public places, and not just during flu season and not just to prevent the spread of flu and colds but diseases like Hanta Virus or the spread of E-Coli bacteria for instance.
But simply put; the more people who are vaccinated for the flu or for that matter measles, chicken pox, mumps, polio, etc., the fewer the number of unvaccinated people get sick because the vector for transmitting the disease is greatly decreased, i.e. herd immunity. Conversely the fewer people who are vaccinated, the greater the disease vector and the greater number of unvaccinated people get sick. There have been pockets where measles and chicken pox have been on the rise and not coincidentally in areas were fewer parents had their children immunized. Small pox has been eradicated due to vaccinations but unlike flu, it is a DNA virus and doesn’t mutate like RNA viruses like the flu, which is why a there is a new vaccine every year. Polio is still found in 3rd world countries because of the lack of immunization, but you don’t hear of cases of Polio here in the US due to mandatory vaccination programs.