Chicken pox (varicella). Besides the initial dose recommended for babies at around a year, now 4- to 6-year-olds will get a booster. New research shows that the first shot's effectiveness tends to wane around this age. (Older kids should get it, too, if they've never had chicken pox; talk to your doctor.)
Flu. Babies and toddlers have been getting annual flu shots for years, but now 3- and 4-year-olds should be vaccinated, too -- starting this October. That's because kids this age, who are just getting out and about but haven't fully built up their immunity, tend to get sick earliest in the season. They pass the flu along to younger siblings (especially infants under 6 months, who can't be immunized) and then to older kids and adults who haven't gotten their shots yet.
HPV (human papilloma-virus). 11- and 12-year-old girls will be offered a three-shot series as protection later on against this sexually transmitted virus, the main cause of cervical cancer.