In a recent review that gathered postlicensure (2006-2016) data from 24 countries, median Rotarix effectiveness rates of 84%, 75%, and 57% were observed in low, medium and high child mortality countries, respectively. In addition, the effectiveness of RotaTeq was 90% and 45% in high and low child-mortality countries, respectively.7
Numerous observational studies conducted in 40 countries have documented a profound positive effect of rotavirus vaccine introduction (See Figure
The global impact of rotavirus vaccination on childhood hospitalizations and mortality from diarrhea during the first 10 years since vaccine licensure was recently evaluated based on evidence from 27 countries, including data from high child mortality settings (See Table
Overall, a median percent decrease of 38% (5%-53%) was seen in all-cause diarrhea admissions among children under 5 years of age; reduction rates of 41%, 30%, and 46% were observed in low, medium, and high child-mortality countries, respectively. Rotavirus vaccination also contributed to an overall significant decline in rotavirus-specific hospitalizations and emergency department visits (67% [18%-84%]), yielding median reduction rates of 71%, 59%, and 60% in low, medium, and high child mortality, respectively.
Moreover, a number of countries have documented a marked decline in all-cause diarrhea-associated mortality among children under 5 years, following vaccine introduction. A median reduction of 42% (3%-64%) was seen overall, whereas declines in diarrheal deaths of 50% and 36% were seen in medium and high child-mortality countries, respectively. Of remarkable public health impact was that benefits from rotavirus vaccines were not restricted only to the age-eligible group for vaccination; they were also evident among children who were too old to be vaccinated. To date, a number of studies in Australia, Austria, Belgium, Brazil, El Salvador, Finland, Ghana, Moldova, and the United States have shown that following rotavirus vaccine introduction, admissions for rotavirus related diarrhea decreased as much as 89% (20%-89%) among this group.2,8
The strong safety records of both vaccines were highlighted in a recent review of efficacy and safety data from 41 trials with 186,263 participants. No differences were found between the vaccine and placebo groups concerning adverse events (AEs) leading to discontinuation of the vaccination schedule. In general, there was a slight chance of minor AEs following vaccination, including irritability, diarrhea, or vomiting.2,9
To date, only 12 (30%) of the 40 countries where the rotavirus vaccine impact is being evaluated are assessing the potential risk of intussusception.5,10
Currently, available data are mainly from post-marketing surveillance studies in Australia, Brazil, Mexico, and the United States, which suggest that there is a com-parable small temporal increase in the risk of intussusception, mainly within 7 days after the first dose, for both available vaccines. Overall there are an estimated 1 to 6 additional cases of intussusception for every 100,000 infants vaccinated.2,6