Every year, tens of thousands of adults die and hundreds of thousands more are hospitalized due to diseases that could have been prevented by vaccination. The cost of this health burden to society, according to the Centers for Disease Control and Prevention (CDC), is roughly $10 billion per year. This failure stands in stark contrast to the success of childhood immunization. By integrating vaccinations into regular early-childhood health care visits—and by supporting them through public programs, for those who cannot afford to pay—many vaccine-preventable diseases are now nearly nonexistent among children aged <5 years in this country. Many of the lessons learned from developing a highly effective pediatric immunization program can be applied to the problem of underimmunization in adults (see the editorial commentary by Hinman and Orenstein 1  in this issue of the journal).

The nation has before it a major opportunity to improve immunization for adults. Newly licensed adult vaccines can prevent shingles (the zoster vaccine) and cervical cancer (the human papillomavirus vaccine). Other vaccines already recommended for many adults can prevent liver cancer (the hepatitis B vaccine) and complications of infections caused by influenza virus and pneumococci. Yet our track record in assuring that adults receive the vaccines recommended for them is poor. Although >90% of young children have received the individual vaccines recommended for them, coverage for adult vaccines can range from 26% to 65%, depending on the vaccine and the target population. For example, <60% of persons aged 50 years have received a dose of tetanus toxoid in the past 10 years 2  and <50% of persons aged 50–64 years at high risk of influenza receive the annual influenza vaccine 3 Coverage rates are even lower for the pneumococcal vaccine in high-risk groups 4 Racial and ethnic disparities compound the problem. Strengthening adult immunization coverage will require significant improvements in the health care system's ability and willingness to provide and deliver vaccines to adults. Policymakers, the public, providers, insurers, employers, and employees need to become more aware of the value of adult immunization. Providers often lack the technical expertise and resources to acquire certain vaccines and to keep them on hand. The infrastructure to deliver vaccines to underinsured and uninsured adults must be significantly bolstered. Vaccine payment in both private and public health sectors must be sufficient to cover costs and to serve as an incentive to make adult immunization a prominent part of the practices of physicians who care for adults. Health care quality measures, surveillance, and research are additional areas that are in need of improvement.

Most vaccines in use today have been recommended for young children or adults. Recently, several new vaccines targeted for adolescents have been licensed and recommended, including vaccines against meningococcal meningitis and cervical cancer and boosters against pertussis ("whooping cough"). Delivery, payment, monitoring, and support systems to vaccinate adolescents also need to be bolstered.

The Infectious Diseases Society of America (IDSA) offers the following principles as a blueprint for action and urges all health care providers, health officials, and policymakers to participate in the solutions. These principles may be further modified as new developments emerge. Improvements in the national capacity to immunize adults and adolescents can help to prevent disease, save lives, and ensure an effective system for the delivery of vaccines now in development. Importantly, this goal should be pursued in a manner that enhances rather than compromises pediatric immunization programs.