the vaccination that causes the scar on your arm is for small pox not chicken pox....small pox vaccinations are not offered anymore...not sure when they stopped doing it but its been awhile. basically all the baby boomer generation is vaccinated against small pox but not their kids. reason is because the disease (which was very fatal to kids back in the day) has been eradicated in the u.s.a.....still exists in 3rd world countries, thats why our military personnel still gets vaccinated.