Update on immunizations in children and adolescents.

Over the past few years, there have been many changes to the recommendations for children and adolescents by the Advisory Committee on Immunization Practices. These include dividing the immunization schedule into two parts (i.e., ages birth to six years and seven to 18 years, with catch-up schedules for each group); expanding the recommendations for influenza vaccine to children ages six months to 18 years without risk factors; expanding coverage for hepatitis A vaccine to include all children at one year of age; initiating routine immunization with oral rotavirus vaccine given at ages two, four, and six months; and adding a booster dose of varicella vaccine at four to six years of age. The tetanus and diphtheria toxoids and acellular pertussis vaccine (Tdap), quadrivalent meningococcal conjugate vaccine (MCV4), and quadrivalent human papillomavirus (HPV) vaccine are routinely recommended for adolescents 11 to 12 years of age. Tdap provides pertussis immunity in addition to the tetanus and diphtheria immunity provided by the tetanus and diphtheria toxoids vaccine (Td). MCV4 has improved immunogenicity compared with the older meningococcal vaccine. HPV vaccine protects against serotypes 6, 11, 16, and 18, and is given in three doses, ideally at 11 to 12 years of age; the effectiveness increases when the vaccine is given before the onset of sexual activity. Family physicians play an integral role in implementing new immunization recommendations and properly educating patients and families in the increasingly complex armamentarium of prevention.