The introduction of rotavirus vaccination in the United States significantly reduced the rates of rotavirus-specific gastroenteritis in all age groups, with the most substantial decreases observed in children between the ages of 0 and 4 years.
“Prior to vaccine introduction in the U.S., rotavirus was the leading cause of severe pediatric gastroenteritis, resulting in up to 70,000 hospitalizations and an estimated $319 million in health care costs annually,” Julia M. Baker, BS, a PhD student at the Rollins School of Public Health at Emory University, and colleagues wrote. “Following pivotal clinical trial results, two live, attenuated oral rotavirus vaccines — RotaTeq (Merck) and Rotarix (GlaxoSmithKline) — were included in the routine infant vaccination schedule in 2006 and 2008. By 2015, 73.2% of children aged 19 to 35 months had received a full course of rotavirus vaccine.”
The researchers wrote that this coverage is modest when compared with other immunizations found in routine schedules, including diphtheria, tetanus and pertussis, which had coverage of 95% for three or more doses in 2015.
Although rotavirus decreased in the U.S. after immunizations were introduced, Baker and colleagues claimed that the impact of the vaccines has not been fully explained on a population level. To examine these effects, they assessed the number of hospital discharges related to acute gastroenteritis for all age cohorts between 2000 and 2013.
Once rotavirus vaccines were introduced in the U.S., rotavirus hospitalizations decreased among children aged 0 to 4 years by 85% (RR = 0.14; 95% CI, 0.09-0.23) — the largest decrease observed by the researchers. Significant overall decreases were also observed in children aged 15 to 19 years, as well as adults aged 20 to 59 years.
The smallest decrease in rotavirus-related hospitalizations was observed among adults aged 60 years and older. However, Baker and colleagues said there were still significant reductions in hospitalizations among this age group after vaccines became available compared with prevaccine years (RR = 0.51; 95% CI, 0.39-0.66).
“Rotavirus vaccination had a substantial impact on rotavirus-specific gastroenteritis hospitalizations across age groups during the 6-year period, highlighting the role of infants as drivers of infection transmission,” the researchers wrote. “Infant vaccination programs increase the average age of infection. Further years’ data will be needed to determine whether there is an absolute increase in disease rates in older age groups.” – by Katherine Bortz
Disclosures: The authors report no relevant financial disclosures.