When discussing women pioneers in science, several names in particular seem to always make their way into the conversation: Marie Curie, Nettie Stevens, Rosalind Franklin. However, few have heard of a talented microbiologist and immunologist whose work has helped to save the lives of millions of children and pave the way for future generations of women scientists: Ruth Bishop.

The current generation of vaccines against rotavirus, the leading cause of diarrheal disease in children under five years old, was introduced just a decade ago. In the intervening years, 81 countries have implemented rotavirus vaccination to prevent diarrheal disease.

Since the administration of the first vaccine, immunization policy has evolved to better meet public health needs around the world. This evolution is most apparent when considering immunization policy in developing countries over the past 50 years.

It takes more than a vaccine to make a successful immunization program. This World Immunization Week, we are taking a look at some of the factors that contribute to effective immunization programs.