Rotavirus infection remains the leading cause of severe diarrheal illness and dehydration in children worldwide.
In 2008, about 450,000 children worldwide under 5 years old died from vaccine-preventable rotavirus infection.
Prior to vaccine development, rotavirus caused 20-60 deaths each year in U.S. children under 5 years of age. Haemophilus influenzae type b (Hib) is a bacteria that causes many different types of disease in children younger than 5 years of age, including brain infection (meningitis), lung infection (pneumonia), and severe throat infection (epiglottitis).
Prior to the Hib vaccine, about 20,000 U.S. children had Hib infections every year, and up to 1,200 children died.
Vaccine research includes developing vaccines in labora- tories, testing effectiveness in humans, testing ways to get children vaccinated and reducing barriers to immu- nizations.
Research into the development of a vaccine to protect against rotavirus infection started in the mid- 1970s.
Studies elucidated the effect of rotavirus on a child’s immune system and how initial exposure to the virus protected that child from future illness.
Once the prototypal rotavirus vaccine was created, subsequent research tested ways of improving its effica- cy while maximizing safety.
Following research and many efficacy and safety studies, the first rotavirus vaccine for widespread public use was approved in 2006.
Studies showed that the most severe infections from Hib tended to
occur in young infants, due to their immature immune systems. A multi-dose vaccine schedule was created in order to maximize the protection of infants from infec- tion with Hib, with the first dose given at 2 months of age.
Receiving the full schedule of rotavirus immunization decreases the occurrence of gastroenteritis by 86% and required hospitalization for gastroenteritis by 96%.
Since the administration of the vaccine, the yearly cases of Hib infection have decreased by 99%.
Currently, most mortality from Hib occurs in developing countries, where vaccination is not routine.