The development and global introduction of rotavirus vaccines were the subject of this year's John F. Enders Lecture, presented by Fogarty Director Dr. Roger I. Glass during Infectious Diseases Week in Philadelphia. The annual keynote address honors the Nobel laureate who helped devise modern tissue culture techniques critical to the development of vaccines against polio, measles, rubella and rotavirus and other areas such as cancer biology. ID Week is hosted by the Infectious Diseases Society of America (IDSA) and its partners.
In his talk, titled "The Global Introduction of Rotavirus Vaccines: Where will this path lead us?," Glass reported that the number of hospitalizations for children with rotavirus has dropped more than 85 percent in the U.S. since vaccination began in 2006. Although there is a very small risk of intussusception - the telescoping of the intestine onto itself - the benefits far outweigh the risks, Glass said. With about 80 percent of U.S. children vaccinated, there have been approximately 50,000 fewer hospitalizations per year, a drop in visits to doctors or clinics, and indirect benefits including a decrease in diarrhea hospitalizations for older children and adults secondary to the protection of their younger children. An estimated one to five cases of intussusception have occurred per 100,000 vaccinated infants resulting in no fatalities in the U.S.
The World Health Organization (WHO) began recommending global use of rotavirus vaccines in 2009 to address the hundreds of thousands of diarrheal deaths that were occurring in children each year, the vast majority in developing countries. By August 2014, some 69 countries had instituted national rotavirus vaccination programs.
Many studies have documented decreased hospitalizations from rotavirus vaccines, with a clear decline in rotavirus deaths in Mexico, Glass said. Several challenges remain before the full impact of rotavirus vaccines can be realized, he noted. Oral vaccines have been less effective in low income countries in Asia and Africa for reasons that are not clearly understood.
Since India has one of the highest rates of rotavirus deaths - about 80,000 per year - Glass has worked with Professor M. K. Bhan and his Indian and American colleagues for several decades to produce a safe, effective and affordable vaccine for India. The vaccine has been licensed and approved for use in India and the Prime Minister has stated that all Indian children will soon receive a rotavirus vaccine free of charge, said Glass.
This is the first new vaccine produced totally in India in a century, using an Indian rotavirus strain, an Indian company, Indian clinical trials and support directly from the government of India, he noted. "While the positive health impact of rotavirus vaccination has been enormous," Glass concluded, "further research is essential to improve the efficacy of existing vaccines in low-income settings and develop less expensive and more effective alternatives."