Genetic diversity of rotavirus strains circulating in Norway before and after the introduction of rotavirus vaccination in children

Abstract

Globally, rotavirus (RV) is the leading cause of acute gastroenteritis (AGE) in young children under 5 years of age. Implementation of RV vaccination is expected to result in fewer cases of RV in the target population, but it is unknown if this also results in vaccine‐induced virus strain replacement. Rotarix, a monovalent vaccine based on G1P[8] RV, was introduced in Norway in the children's immunization program in September 2014. The main aim of this study was to describe the diversity of RV circulating pre and post introduction of the RV vaccine in Norway and investigate changes in genotype distribution during the first 4 years after implementation. A total of 1108 samples were collected from children under 5 years enrolled with AGE from five large hospitals in Norway and were analyzed for RV by enzyme immunoassay (EIA). All positive results were genotyped by multiplex semi‐nested reverse transcription PCR for identification of G and P types. In total, 487 of the 1108 (44%) samples, collected from the enrolled children, were positive for RV by EIA method which were further genotyped. G1P[8] was found to be the most common type of RV pre and post RV vaccine implementation followed by G9P[8]. There were neither geographical nor temporal differences in genotype dominance. Also, no apparent changes were shown in the genotype distribution in the postvaccine era for years from 2015 to 2018. In 21.4% of the cases, vaccine strains were detected. Continuous RV genotype surveillance is vital for assessing the effectiveness of a vaccine program and monitoring for any emergence of vaccine‐escape strains. Genotyping is also necessary to detect vaccine strains to avoid reporting false‐positive cases of active RV infection in newly vaccinated cases.

Genotype Diversity of Enteric Viruses in Wastewater Amid the COVID-19 Pandemic

“…The introduction of RV vaccination has succeeded in nearly halving the number of global RV deaths from 453,000 in 2008 to 215,000 in 2013 (Moyo et al, 2014; Tate et al, 2012). Indeed, RV vaccines continue to be successful in minimizing disease severity as well as hospitalizations and thus reducing mortality from RV infection, but the infection nevertheless remains ineradicable, showing multiple outbreaks and greater diversity of circulating RV genotypes in the post-vaccination period documented in our previous studies (Hoque et al, 2020 ; Okitsu et al, 2022 ) as well as by other groups (Gibory et al, 2022 ; Gikonyo et al, 2020 ; Tsugawa et al, 2021 ). A similar diversity of RV genotypes was observed in the present study at SW (Table 1 ).…”

Comparing single versus multiple virus detection in pediatric acute gastroenteritis postimplementation of routine multiplex RT‐PCR diagnostic testing

“…Despite substantial efforts in rotavirus vaccination and the presence of high vaccination rates among rotavirus‐positive children, it remains the most prevalent virus in our study, often in combination with norovirus. The distribution of rotavirus types shows significant variation between different countries, hinting at strain replacement and a potential vaccine escape phenomenon 17 . Nevertheless, further studies on the genetic diversity of circulating viruses are needed to explore this aspect.…”

“…The distribution of rotavirus types shows significant variation between different countries, hinting at strain replacement and a potential vaccine escape phenomenon. 17 Nevertheless, further studies on the genetic diversity of circulating viruses are needed to explore this aspect.…”

Multicenter Study of Rotavirus Infection, Diversity of Circulating Genotypes and Clinical Outcomes in Children ≤5 Years Old in Iran

“…These findings align with a recent study in Norway, where G1P[8] was the most common genotype in similar age groups. 31 However, a study in India reported a higher prevalence of G1P[8] in children under 36 months and a lower infection with G9P[4] genotype in older children. 32 The tendency of specific RVA genotypes in certain age groups could be attributed to differences in host factors and the virus genotypes in different populations.…”