Acute Gastroenteritis; delayed penta concordant 2nd dose; missed last dose of rotarix vaccine; This case was reported in a literature article and described the occurrence of acute gastroenteritis in a infant patient who received Rota (Rotarix liquid formulation) for prophylaxis. Co-suspect products included DTPw-HBV+Hib (DTPw-HBV/Hib) for prophylaxis and Rota (Rotarix) for prophylaxis.   Previously administered products included DTPw-HBV/Hib (1st dose on an unknown date).   On an unknown date, the patient received the 1st dose of Rotarix liquid formulation, the 2nd dose of DTPw-HBV/Hib and the 2nd dose of Rotarix. On an unknown date, unknown after receiving Rotarix liquid formulation and DTPw-HBV/Hib and not applicable after receiving Rotarix, the patient experienced acute gastroenteritis (serious criteria hospitalization), drug dose administration interval too long and incomplete course of vaccination. On an unknown date, the outcome of the acute gastroenteritis, drug dose administration interval too long and incomplete course of vaccination were unknown.   It was unknown if the reporter considered the acute gastroenteritis to be related to Rotarix liquid formulation and DTPw-HBV/Hib.  Additional details were provided as follows: This case was reported in a literature article and described the missed dose (incomplete course of vaccination) in an infant aged between 14 weeks and 36 months who was vaccinated with diphtheria-tetanus-whole cell pertussis-hepatitis B-Haemophilus influenzae type B (DTPw-HepB-Hib) vaccine (manufacturer unknown) and rotarix vaccine (GlaxoSmithKline) for prophylaxis. This case corresponds to supplementary table number 4 reported in this literature article. The patient was part of the active rotavirus surveillance platform from 2013 to 2017. That aimed to examined the timeliness of rotavirus vaccine versus DTPw-HepB-Hib (pentavalent) vaccine first dose and last dose were compared at 15 and 32 weeks of age, respectively, which was concurrently administered without age restrictions, in two RV1 (rotarix) introducing countries (April 2012) and (May 2014) and two RV5 (Rotateq) introducing countries that implemented vaccination between 2012 and 2014. As these countries made the decision to implement rotavirus vaccination prior to or soon after WHO0s 2013 decision to remove age restrictions. They hypothesized that the previous age restrictions might have had some impact on the timeliness of rotavirus vaccination. [In this study, Surveillance and enrollment periods varied by country. A stool specimen that tested rotavirus-negative were included in the analysis. A total 3568 Rotavirus-genagtive children were enrolled in the surveillance programs, 1592 children from one country, median age ranged from 45 to 49 weeks old, 669 were female]. No information on patient's medical or family history or concurrent condition were provided. [In this study, on unspecified date, the 1469 patient's received 1st dose of rotarix on-time (penta concordant dose) 1st dose of diphtheria-tetanus-whole cell pertussis-hepatitis B-Haemophilus influenzae type B (DTPw-HepB-Hib) vaccine and 22 patient's received 1st dose of rotarix as delayed (penta concordant dose) (administration route and site unspecified, batch number not provided for both vaccines). The age of vaccination was not provided]. On unspecified date, the patient had received delayed (penta concordant dose) 2nd dose of diphtheria-tetanus-whole cell pertussis-hepatitis B-Haemophilus influenzae type B (DTPw-HepB-Hib) vaccine (manufacturer unknown) and missed last dose of rotarix vaccine (administration route and site unspecified, batch number not provided for both vaccines). The age of vaccination was not provided. [In this study, two oral live attenuated rotavirus vaccines are currently licensed for global use Rotarix (RV1), a 2-dose vaccine administered at 6 and 10 weeks of age. The countries introduced rotavirus vaccine at (May 2014). In 2009, the World Health Organization (WHO) recommended routine vaccination against rotavirus worldwide, with unique age recommendations to administer the first dose before 15?weeks of age and last dose by 32?weeks of age. This analysis includes infant, who were born at least 2 months after rotavirus vaccine was introduced into the national vaccination program. For the last dose of RV1, the concordant pentavalent dose was the second dose in the series]. On an unspecified date, unknown period after vaccination, the patient fecal specimen was obtained to test for the rotavirus and the patient experienced acute gastroenteritis. The patient hospitalized from October 2014 to December 2016. Due to the delayed penta concordant 2nd dose, the patient missed last dose of rotarix, which led to missed dose (i.e incomplete course of vaccination). [In this study, a missed opportunity for rotavirus vaccine was defined as a pentavalent vaccine dose administration without concordant rotavirus vaccine dose administration. Delayed vaccine administration was defined as vaccine administration at least 1 week after the recommended rotavirus vaccination schedule. Active surveillance for acute gastroenteritis hospitalizations was conducted using the WHO generic protocol and a fecal specimen was obtained to test for rotavirus. The median number of months between the date of rotavirus vaccine introduction and the date of admission was lowest for children in  (24 months)]. Treatment was unknown. The outcome of the event was not provided. The author commented, "Delayed pentavalent vaccine administration was clearly associated with missed rotavirus vaccination opportunity for the first dose alone. Children who received a delayed concordant dose of pentavalent vaccine were also more likely to miss a last dose of rotavirus vaccine as compared to children who had received concordant pentavalent dose on time, and findings were not confounded by age on admission, months between vaccine introduction and admission date, and sex. However, when restricting the cohort to children who had received first dose of rotavirus vaccine and pentavalent vaccine, there was no association between missed last dose of rotavirus vaccine and timeliness of concordant pentavalent dose in any country. This indicates that rotavirus vaccine lastdose findings were driven primarily by missed rotavirus vaccine first doses." The author concluded "Rotavirus vaccine administration was timely among children enrolled at sentinel sites in these four early rotavirus vaccine introducing countries, and age restrictions had minimal impact on rotavirus vaccine use due to timely vaccine administration. In countries with less timely vaccine administration, disparities in coverage between rotavirus vaccine and pentavalent vaccine may be more prominent if age restrictions continue to be followed to some extent and this should be examined in future evaluations.". This is 1 of the 2 valid cases reported in this literature article.      Lab Comments: Lab test done on an unknown date between October 2014 to December 2016. In this study, a stool specimen that tested rotavirus-negative were included in the analysis. A total 3568 Rotavirus-genagtive children were enrolled in the surveillance programs.