Detection of Rotavirus Genotypes in Korea 5 Years after the Introduction of Rotavirus Vaccines

Abstract

Rotavirus (RV) is one of the most important viral etiologic agents of acute gastroenteritis (AGE) in children. Although effective RV vaccines (RVVs) are now used worldwide, novel genotypes and outbreaks resulting from rare genotype combinations have emerged. This study documented RV genotypes in a Korean population of children with AGE 5 yr after the introduction of RVV and assessed potential genotype differences based on vaccination status or vaccine type. Children less than 5-yr-old diagnosed with AGE between October 2012 and September 2013 admitted to 9 medical institutions from 8 provinces in Korea were prospectively enrolled. Stool samples were tested for RV by enzyme immunoassay and genotyped by multiplex reverse-transcription polymerase chain reaction. In 346 patients, 114 (32.9%) were RV-positive. Among them, 87 (76.3%) patients were infected with RV alone. Eighty-six of 114 RV-positive stool samples were successfully genotyped, and their combinations of genotypes were G1P[8] (36, 41.9%), G2P[4] (12, 14.0%), and G3P[8] (6, 7.0%). RV was detected in 27.8% of patients in the vaccinated group and 39.8% in the unvaccinated group (P=0.035). Vaccination history was available for 67 of 86 cases with successfully genotyped RV-positive stool samples; RotaTeq (20, 29.9%), Rotarix (7, 10.4%), unvaccinated (40, 59.7%). The incidence of RV AGE is lower in the RV-vaccinated group compared to the unvaccinated group with no evidence of substitution with unusual genotype combinations.Graphical Abstract

Changing distribution of age, clinical severity, and genotypes of rotavirus gastroenteritis in hospitalized children after the introduction of vaccination: a single center study in Seoul between 2011 and 2014

“…A relative increase of the G2P[4] genotype was also observed, which was significantly associated with age and clinical severity in this population. Although these are the results from a single hospital with a modest number of fecal samples, a considerable number of findings in clinical and molecular epidemiology share similar trends observed in other single center studies from Seoul and some multi-center Korean studies conducted in the post-vaccine period [ 2 , 5 , 10 , 27 – 29 ]. To our knowledge, this is one of the first attempts to explore the link between age, clinical severity and genotypes in a region that adopted the rotavirus vaccination, which may contribute to an integrated understanding of the changing patterns in both clinical and molecular epidemiology for rotavirus gastroenteritis after the introduction of vaccines.…”

“…Although the proportion of G9 genotype was significantly higher in the vaccinated group, the significance of this observation could not be determined because of a relatively low significant P value ( P = 0.010) in a small number of vaccinated children ( n = 19). In previous two Korean studies, although the number of vaccinated children was also small, there was no significant difference in the genotype distribution between vaccinated children and those unvaccinated [ 27 , 28 ].…”

“…G9 was first detected in 2002 and was identified in consecutive seasons mostly as G9P[8] [ 22 , 23 , 25 ], becoming the fifth most common genotype in Korea [ 17 , 26 ]. After the introduction of rotavirus vaccines, G1P[8] has remained predominant, however, the prevalence of G2P[4] seemed to have increased around 2013 in Korea [ 27 , 28 ]. especially in Seoul, compared to the early vaccination period, although only a few studies on the surveillance of genotypes are available in the literature [ 27 – 29 ].…”

“…After the introduction of rotavirus vaccines, G1P[8] has remained predominant, however, the prevalence of G2P[4] seemed to have increased around 2013 in Korea [ 27 , 28 ]. especially in Seoul, compared to the early vaccination period, although only a few studies on the surveillance of genotypes are available in the literature [ 27 – 29 ].…”

Platform technologies for modern vaccine manufacturing

“…RNA viruses such as influenza and human immunodeficiency virus [14,15]) or existing as multiple genotypes and serotypes (e.g. rotavirus [16,17], enterovirus [18] and the Group A Streptococcus [19]) present a challenge for developing efficacious vaccines. While this is an important consideration for all vaccine manufacturing platforms, the current timescale of traditional vaccine manufacturing highlights their inadequacy.…”