Could you please elaborate how someone not-vaxing who gets sick can hurt a vaxed person? I hear this argument some times but no-one was able to explain how this works.
This is why having high vaccination rates are so important. There is a percentage who can't be vaccinated (age, health issues, whatever), there's an unknown percentage for whom the vaccination just didn't work, and then there's the wide circle of immunity formed around them by everyone else who is immune and up to date on those immunizations.
The other side of the issue is that vaccinations do not guarantee immunity from a disease. Exposure to a disease puts anyone at risk but they are much less likely to get it if they are vaccinated but they still can get it none the less.
Because vaccines, while very effective, are less than perfectly effective. Vaccines have a first order effect of reducing the vaccinated person's chance of getting the disease when exposed, and a second order effect of reducing everyone else's chance of getting exposed.
[1] http://www.forjudeforeveryone.com/2017/02/22/how-herd-immuni...
Nowadays there is a new problem of people spreading the myth that vaccination is known to be dangerous to infants, so it is not politically acceptable to lower the vaccination age. This is even though we know the maternal antibodies of vaccinated mothers wear out sooner than those of earlier generations (who generated them in response to a full on infection).
I explained this a number of times in an earlier thread: https://news.ycombinator.com/item?id=13655795
For example here: https://news.ycombinator.com/item?id=13656462
Yes, for two reasons:
1) It is not the vaccinated/unvaccinated state that determines whether someone is susceptible to measles. Instead, it is whether they have antibodies towards the virus. One reason to have antibodies towards the virus is vaccination, another would be having had a measles infection in the past, and the most important to us here is being recently (~1 yr) born from a mother that has antibodies. The newborns are already protected from measles, there is no reason to be concerned about exposing them to measles until the maternal antibodies wear off.
2) This myth is an obstacle to preventing the spread of measles because it is not possible to lower the vaccination age to account for the more quickly waning maternal antibodies generated by vaccinated (as opposed to previously infected) mothers. By repeating this myth you are helping to spread measles.
> "Unless we immeduatly vaccinate everyone as soon as they leave the womb (unlikely / impossible) there will always be unvaccinated people."
So what if the newborns are unvaccinated? They are already protected by the maternal antibodies. Further, even if you did vaccinate them, it would fail to elicit immunity because the maternal antibodies would just neutralize the vaccine. I feel like I am repeating myself here though...