Originally Posted By: 1 FMF
with the anti vaccine movement getting publicity, i see comments by pro vaccine people to the anti vaccine people like: "get your kids vaccinated dont endanger my kids."
now assuming pro vaccine people had their kids vaccinated, how would their kids be endangered by unvaccinated kids in school?
wouldnt they be 'immune' is that not the definition of vaccination?
That is NOT a dumb question!
There are two basic answers to your question. First, no vaccine is 100% effective, in 100% of a population--because there is such a thing as vaccine failure--which has been assessed by various researchers at about, on average, 3% to 5% for some viral vaccines given to children/adults (i.e. measles, rubella, mumps, polio, hepatitis A or B, etc.). For bacterial diseases (i.e. pertussis [whooping cough], tetanus, diphtheria, Hib, etc.) the range is about 90% to 98% or so, depending on which vaccine/disease is at question. We've all heard a good bit about "herd immunity" recently. That is the concept that if a large number of individuals are immune to a disease, then the number of possible susceptible individuals to that disease can be reduced such that an outbreak is less likely to occur. Less likely doesn't mean impossible.
In the real world of public health and childhood vaccine preventable diseases, especially in school and/or daycare environments, this can occur: An outbreak of a disease! Here's why. For viral vaccine preventable diseases approximately 3 to 5 children per 100 children, who have been vaccinated are NOT immune. In general, for bacterial vaccine preventable diseases the range can be about 2% to 10% who have been vaccinated--but are NOT immune. Exactly why some children, or adults, do not respond to a particular vaccine is not completely understood. If a more complete answer of that question could be given a Nobel Prize for Medicine would be assured.
In the case of a measles outbreak, such as at Disneyland, just one person can infect any number of persons they are in contact with who are not immune because they have not had the vaccine, or they did not become immune after receiving the vaccine. So, randomly distributed among us are those people who have had the measles vaccine but it didn't "take." In a busy place like Disneyland, with thousands of people in any one place you can roughly figure that there are 30 (3%) to 50 (5%) per 1,000 people who are at risk. If, just one of those at risk persons comes into contact with an infected person--it's off to the races! Because measles is so contagious, you can be sure there will be subsequent cases to patient zero.
The second answer to the other part of your question is that young children, those who are less than age two, are at the most risk of childhood vaccine preventable diseases because they either are not old enough to receive some vaccines, or because they are still in the process of receiving vaccines that must be given in a series of doses over a period of six to eighteen months to maximum protection.
Because we live in an imperfect world, where diseases cause serious harm, we as adults must all take seriously the risk of disease versus the benefit of vaccines for the children we are privileged to have. Even after 40+ years of working in the public health field of vaccines and childhood diseases, I've come to the conclusion that one cannot reach all or even some of the anti-vaxers. Actually, I don't feel too bad about not reaching all those people over the years! I do know that if the Pope in Rome, the Grand Tut-Tut in Mecca, or the Deli Lama of Tibet, or the Rabbi in East Halfasack, NJ can't reason with or reach all of their washed-unwashed masses, then I don't feel so bad.