Our 20th century has been marked by major breakthroughs in science and public health — none more so than childhood immunizations. The number of vaccines recommended for children has grown from four in the 1950s (polio, pertussis, diphtheria, and tetanus) to thirteen distinct vaccines (if we include the recent FDA approval of rotavirus vaccine), with multiple vaccines in the pipeline (human pappilomavirus, herpes, RSV, streptococcus, and parainfluenza).
