Yellow fever vaccine Foundation to improve the vaccine from the "Asibi" strain, discovered that a favorable chance mutation in the attenuated virus had produced a highly efficacious strain that was named 17D. After field trials in Brazil, over one million people were vaccinated by 1939, without severe complications. For his work on the yellow fever vaccine, Theiler received the 1951 Nobel Prize in Physiology or Medicine. Only the 17D vaccine remains in use today. The outbreak of yellow fever in Angola in January 2016 has raised concerns about whether the global supply of vaccine is adequate to meet the need during a large
Rotavirus vaccine countries in the world to introduce rotavirus vaccine, the diarrheal disease death rates from rotavirus dropped by more than 65% among children age two and under during the 2009 rotavirus season . In Nicaragua, which in 2006 became the first developing country to introduce the rotavirus vaccine, investigators recorded a substantial impact, with rotavirus vaccine preventing 60% of cases against severe rotavirus and cutting emergency room visits in half. In the United States, vaccination has reduced rotavirus-related hospitalizations by as much as 86% since 2006. Recent studies in developing countries that have introduced rotavirus vaccines have supported these findings, showing