Vaccination 101.
Since the early 70's, in the U.S. all kids must have at least 1 MMR given
AFTERtheir first birthday in order to go to school in NY - other states may be slightly different. If it's given when they're younger, the baby may lose immunity (since their immune system isn't completely mature.) Some states require 2 doses of MMR (the second dose is usually given around age 6, but as long as it's at least 30 days apart from the first, it's all good. And it can be given years apart, actually.) This 2nd dose requirement was mainly due to several measles outbreaks in the early 1990's.
Over the past few months there's been a mumps outbreak, esp. in the Midwest U.S. It's usually harmless, but can be dangerous in rare cases. Oh, and it sucks.
Many people are now getting a second (or even third) booster dose of MMR due to this outbreak.
Nobody knows for sure why people are still getting these diseases if they've already been immunized, but it does happen. Maybe it's a slightly different strain, or the person's immunity faded over time. Plus, other nations are different - many international students come here with NO immunizatioons at all.
Pretty scary. They're not exposed to these diseases in their country, but when they come to the U.S. they are at risk for developing them. Chicken Pox is a real bitch when you're a 20 year old college student.
As a kid in the U.S. in the 70's & 80's, we needed MMR (1 or 2), polio (series of 5), DPT (diptheria, pertussis, tetanus - series of 4) and that was about it. Since the early 90's, kids need those PLUS Hepatitis B (series of 3) & Varicella (chicken pox - series of 2), and some states require Hepatitis A (series of 2) and meningitis (1 every 5-10 years) as well, plus flu shots annually & sometimes a pneumonia vaccine. The new HPV vaccine is sure to become a requirement eventually.
Cost is another issue. Pretty much all insurances cover childhood vaccines, but if you're an adult & need any later due to travelling or exposure, many times you're SOL. Varicella is about $65 per dose, Hep A&B are $30 per dose, MMR is only $10, tetanus is around $20.
Part of me is thrilled that we're preventing disease, part of me thinks "it's just chicken pox, and where the hell would a little kid get Hep B?" So I'm a bit torn. Not like there's much of a choice anymore, most of these vaccines are REQUIRED by law to attend school. But again, I'm torn.