Vaccines Today

In 20th-century medicine, vaccines helped to alleviate an enormous burden of disease. Cases of childhood illnesses that were once common in the United States have been reduced by two orders of magnitude. Before the introduction of a vaccine for measles, an average of 500 000 cases of measles were reported annually from 1958 to 1962; only 89 cases were diagnosed in 1998. Wild-type polio has been eliminated from the western hemisphere, and smallpox has been eliminated from the globe. New vaccines to combat varicella and pneumococcal infections in infants have recently been approved, and others are in clinical trials. An international team is working to eradicate polio within 5 years, and the elimination of measles is being discussed.

Despite this record of success, specialists in public health and infectious disease confront a mixed prospect. Although the diseases that vaccines fight have been minimized or eradicated, vaccine-related side effects, both real and perceived, have become more salient. Actual problems with some vaccines, such as those for polio and rotavirus, have eroded confidence among some in the idea of vaccination. A small but active antivaccine movement has arisen, aided by sensational reports on the Internet and in the media. Meanwhile, back in the laboratory, there is still much to learn about the underlying science needed to create vaccines for major diseases, such as malaria, tuberculosis, and HIV infection (Ann Intern Med. 2000; 133:489-90).