Introducing ROTAVAC® to the occupied Palestinian Territories: Impact on diarrhea incidence,rotavirus prevalence and genotype composition

BackgroundRotavirus infection remains an important cause of morbidity and mortality in children. The introduction of vaccination programs in more than 100 countries has contributed to a decrease in hospitalizations and mortality. This study investigates the epidemiological impact of the rotavirus vaccine ROTAVAC® in the Palestinian Territories, the first country to switch from ROTARIX® to this new vaccine.MethodsClinical surveillance data was collected from children younger than 5 attending outpatient clinics throughout Gaza with diarrhea between 2015 and 2020. The incidence of all-cause diarrhea was assessed using an interrupted time-series approach.Rotavirus prevalence was determined at the Caritas Baby Hospital in the West Bank using ELISA on stool specimen of children younger than 5 with diarrhea. Genotyping was performed on 325 randomly selected rotavirus-positive samples from January 2015 through December 2020 using multiplex PCR analysis.ResultsAverage monthly diarrhea cases dropped by 16.7% annually from introduction of rotavirus vaccination in May 2016 to the beginning of the SARS-CoV-2 epidemic in March 2020 for a total of 53%. Case count declines were maintained after the switch to ROTAVAC® in October 2018. Rotavirus positivity in stool samples declined by 67.1% over the same period without change following the switch to ROTAVAC®.The distribution of predominant genotypes in rotavirus-positive stool samples changed from a pre-vaccination G1P [8] to G9P[8] and G12P[8] during the ROTARIX® period and G2P[4] after the introduction of ROTAVAC®.ConclusionROTAVAC® has shown epidemiological impact on par with ROTARIX® after its introduction to the national immunization schedule in the Palestinian Territories. A molecular genotype shift from a pre-vaccination predominance of G1P[8] to a current predominance of G2P[4] requires more long-term surveillance.     

Early impact of rotavirus vaccine in under 5 year old children hospitalized due to diarrhea,Swaziland

BackgroundSwaziland introduced rotavirus vaccine in the National Immunization Program, in May 2015, with the objective of reducing the burden of rotavirus diarrheal disease. We monitored the early impact of the vaccine in reducing rotavirus diarrhea.MethodsWe conducted sentinel rotavirus surveillance from January 2013 to December 2016 in children under five years of age admitted due to diarrhea attending Mbabane Government Referral Hospital in the Hhohho Region and Raleigh Fitkin Memorial Hospital in the Manzini Region. All cases had stool samples collected and tested for rotavirus antigen by enzyme immunoassay.ResultsBetween 2013 and 2016, 596 samples were collected and tested. Rotavirus positivity reduced from average of 50.8% (172/338) (in 2013–2014 (pre vaccine period)) to 29% (24/82) in 2016, post-vaccine introduction. The median age of children with rotavirus infection increased from average of 10 months in 2013–2014 to 13.7 months in 2016. The peak season for all-cause diarrhea and rotavirus-specific hospitalizations among children under five years of age was June–August in all years with a blunting of the peak season in 2016. Rotavirus positivity among children 0–11 months reduced from an average of 49% in 2013–2014 (116/236) to 33% (15/45) in 2016, a 33% reduction following rotavirus vaccine introduction.ConclusionThere has been a rapid reduction of all-cause diarrhea and rotavirus hospitalizations in Swaziland, particularly in young children and during the rotavirus season, after the introduction rotavirus vaccine. Continued surveillance is needed to monitor the long-term impact of rotavirus vaccine introduction.     

Temporal association of rotavirus vaccination and genotype circulation in South Africa: Observations from 2002 to 2014

BackgroundRotavirus vaccination has reduced diarrhoeal morbidity and mortality globally. The monovalent rotavirus vaccine was introduced into the public immunization program in South Africa (SA) in 2009 and led to approximately 50% reduction in rotavirus hospitalization in young children. The aim of this study was to investigate the rotavirus genotype distribution in SA before and after vaccine introduction.Materials and methodsIn addition to pre-vaccine era surveillance conducted from 2002 to 2008 at Dr George Mukhari Hospital (DGM), rotavirus surveillance among children <5 years hospitalized for acute diarrhoea was established at seven sentinel sites in SA from April 2009 to December 2014. Stool specimens were screened by enzyme immunoassay and rotavirus positive specimens genotyped using standardised methods.ResultsAt DGM, there was a significant decrease in G1 strains from pre-vaccine introduction (34%; 479/1418; 2002–2009) compared to post-vaccine introduction (22%; 37/170; 2010–2014; p for trend <.001). Similarly, there was a significant increase in non-G1P[8] strains at this site (p for trend <.001). In expanded sentinel surveillance, when adjusted for age and site, the odds of rotavirus detection in hospitalized children with diarrhoea declined significantly from 2009 (46%; 423/917) to 2014 (22%; 205/939; p < .001). The odds of G1 detection declined significantly from 2009 (53%; 224/421) to 2010–2011 (26%; 183/703; aOR = 0.5; p < .001) and 2012–2014 (9%; 80/905; aOR = 0.1; p < .001). Non-G1P[8] strains showed a significant increase from 2009 (33%; 139/421) to 2012–2014 (52%; 473/905; aOR = 2.5; p < .001).ConclusionsRotavirus vaccination of children was associated with temporal changes in circulating genotypes. Despite these temporal changes in circulating genotypes, the overall reduction in rotavirus disease in South Africa remains significant.     

Impact of routine rotavirus vaccination on all-cause and rotavirus hospitalizations during the first four years following vaccine introduction in Rwanda

BackgroundRwanda introduced pentavalent rotavirus vaccine into its national immunization program in 2012. To determine the long-term impact of rotavirus vaccine on disease burden in a high burden setting, we examined trends in rotavirus and all-cause diarrhea hospitalizations in the first four years following rotavirus vaccine introduction.MethodsWe used data from an active surveillance system, from a review of pediatric ward registries, and from the Health Management Information System to describe trends in rotavirus and all-cause diarrhea hospitalizations from January 2009 through December 2016. Percent reductions were calculated to compare the number of all-cause and rotavirus diarrhea hospitalizations pre- and post-rotavirus vaccine introduction.ResultsThe proportion of diarrhea hospitalizations due to rotavirus declined by 25–44% among all children <5 years of age during 2013–2015 with a shift in rotavirus hospitalizations to older age groups. The proportion of total hospitalizations due to diarrhea among children <5 years of age decreased from 19% pre-vaccine introduction to 12–13% post-vaccine introduction. In the national hospital discharge data, substantial decreases were observed in all-cause diarrhea hospitalizations among children <5 years of age in 2013 and 2014 but these gains lessened in 2015–2016.DiscussionContinued monitoring of long-term trends in all-cause diarrhea and rotavirus hospitalizations is important to ensure that the impact of the vaccination program is sustained over time and to better understand the changing age dynamics of diarrhea and rotavirus hospitalizations in the post-vaccine introduction era.     

Impact of rotavirus vaccination on diarrheal hospitalizations in children younger than 5 years of age in a rural southern Mozambique

BackgroundRotavirus vaccine (Rotarix®) was introduced in Mozambique through its Expanded Program of Immunization in September 2015. We assessed the impact of rotavirus vaccination on childhood gastroenteritis-associated hospitalizations post-vaccine introduction in a high HIV prevalence rural setting of southern Mozambique.MethodsWe reviewed and compared the trend of hospitalizations (prevalence) and incidence rates of acute gastroenteritis (AGE), and rotavirus associated-diarrhea (laboratory confirmed rotavirus) in pre- (January 2008–August 2015) and post-rotavirus vaccine introduction periods (September 2015–December 2020), among children <5 years of age admitted to Manhiça District Hospital.ResultsFrom January 2008 to December 2020, rotavirus vaccination was found to contribute to the decline of the prevalence of AGE from 19% (95% CI: 18.14–20.44) prior to the vaccine introduction to 10% (95% CI: 8.89–11.48) in the post-introduction period, preventing 40% (95 % IE: 38–42) and 84% (95 % IE: 80–87) of the expected AGE and laboratory confirmed rotavirus cases, respectively, among infants. Similarly, the overall incidence of rotavirus was 11.8-fold lower in the post-vaccine introduction period (0.4/1000 child-years-at-risk [CYAR]; 95% CI: 0.3–0.6) compared with the pre-vaccination period (4.7/1000 CYAR; 95% CI: 4.2–5.1) with the highest reduction being observed among infants (16.8-fold lower from the 15.1/1000 CYAR in the pre-vaccine to 0.9/1000 CYAR in the post-vaccine eras).ConclusionsWe documented a significant reduction in all-cause diarrhea hospitalizations and rotavirus positivity after vaccine introduction demonstrating the beneficial impact of rotavirus vaccination in a highly vulnerable population.     

Impact of pentavalent rotavirus vaccine against severe rotavirus diarrhoea in The Gambia

IntroductionRotavirus vaccines protect against the leading cause of severe childhood diarrhoea, and have been introduced in many low-income African countries. The Gambia introducedRotateq® (RV5) into their national immunization program in 2013. We revieweddata from an active rotavirus sentinel surveillancesitefor early evidence of vaccine impact.MethodsWe compared rotavirus prevalence in diarrhoeal stool in children< 5 years of age admittedat the Edward Francis Small Teaching Hospital sentinel surveillance site before (2013) andafterRV5 introduction (2015–2016) in the Gambia. The rotavirus-percent positive was separately compared for all diarrhoealhospitalizations and for hospitalizations with severe symptoms. Rotavirus prevalence was compared annually for the pre-vaccine year of 2013 with post-vaccine years of 2015 and 2016 using chi-square or Fisher’s exact tests and the p-value to establish significant relationship was set at p < 0.05. All analyses were completed in SAS 9.3 (SAS Analytics, North Carolina).ResultsRotavirus prevalence among all diarrhoeahospitalizations decreased from 22% in 2013 to 11% in 2015 (p = 0.04), while remaining unchanged in 2016 (18%, p = 0.56). For hospitalizations that were clinically severe and/or treated with intravenous fluids (mean of 46 per year), the rotavirus prevalence decreased from 33% in 2013 to 8% in 2015 (p = 0.04), and to 15% in 2016 (p = 0.08). The children with age <1 year accounted for 45% the population infected with rotavirus in both pre and post rotavirus vaccination periods.ConclusionsRotavirus vaccine introduction in the Gambia could be among factors resulting in decreased diarrhea hospitalizations among children at the Edward Francis Small Teaching Hospital, particularly those with severe disease. These results support the continuation of rotavirus vaccine and additional monitoring of rotavirus hospitalization trends in the country.     

Impact of rotavirus vaccine introduction and genotypic characteristics of rotavirus strains in children less than 5 years of age with gastroenteritis in Ethiopia: 2011–2016

IntroductionA monovalent rotavirus vaccine was introduced in the Ethiopian Expanded Program on Immunization from November 2013. We compared impact of rotavirus vaccine introduction on rotavirus associated acute diarrhea hospitalizations and genotypic characteristics of rotavirus strains pre-and post-vaccine introduction.MethodsSentinel surveillance for diarrhea among children <5 years of age was conducted at 3 hospitals in Addis Ababa, Ethiopia from 2011 to 2017. Stool specimens were collected from enrolled children and tested using an antigen capture enzyme immunoassay. Rotavirus positive samples (156 from pre- and 141 from post-vaccination periods) were further characterized by rotavirus genotyping methods to identify the predominant G and P types circulating during the surveillance era.ResultsA total of 788 children were enrolled during the pre- (July 2011-June 2013) and 815 children during the post-vaccination (July 2014-June 2017) periods. The proportion of diarrhea hospitalizations due to rotavirus among children <5 years of age declined by 17% from 24% (188/788) in the pre-vaccine period and to 20% (161/185) in post-vaccine introduction era. Similarly, a reduction of 18% in proportion of diarrhea hospitalizations due to rotavirus in children <12 months of age in the post (27%) vs pre-vaccine (33%) periods was observed. Seasonal peaks of rotavirus declined following rotavirus vaccine introduction. The most prevalent circulating strains were G12P[8] in 2011 (36%) and in 2012 (27%), G2P[4] (35%) in 2013, G9P[8] (19%) in 2014, G3P[6] and G2P[4] (19% each) in 2015, and G3P[8] (29%) in 2016.DiscussionFollowing rotavirus vaccine introduction in Ethiopia, a reduction in rotavirus associated hospitalizations was seen in all age groups with the greatest burden in children <12 months of age. A wide variety of rotavirus strains circulated in the pre- and post-vaccine introduction periods.     

Impact of rotavirus vaccination on rotavirus and all-cause gastroenteritis in peri-urban Kenyan children

A monovalent rotavirus vaccine (RV1) was introduced into the National Immunization Program in Kenya in July 2014. We examined the impact of the vaccine on hospitalization for all-cause acute gastroenteritis (AGE) and rotavirus-specific AGE and strain distribution at a large referral hospital which serves a predominantly peri-urban population in Central Kenya. Data on rotavirus AGE and strain distribution were derived from ongoing hospital-based AGE surveillance. Hospital administrative data were used to compare trends in all-cause AGE. Pre-vaccine (July 2009–June 2014) and post-vaccine (July 2014–June 2016) periods were compared for changes in hospitalization for all-cause AGE and rotavirus AGE and strain distribution. Following the vaccine introduction, the proportion of children aged <5 years hospitalized for rotavirus declined by 30% (95% CI: 19–45%) in the first year and 64% (95% CI: 49–77%) in the second year. Reductions in rotavirus positivity were most pronounced among the vaccine-eligible group (<12 months) in the first year post-vaccination at 42% (95% CI: 28–56%). Greater reductions of 67% (95% CI: 51–79%) were seen in the second year in the 12–23 months age group. Similarly, hospitalizations for all-cause AGE among children <5 years of age decreased by 31% (95% CI: 24–40%) in the first year and 58% (95% CI: 49–67%) in the second year of vaccine introduction. Seasonal peaks of rotavirus and all-cause AGE were reduced substantially. There was an increased detection of G2P[4], G3P[6] and G3P[8], which coincided temporally with the timing of the vaccine introduction. Thus, introducing the rotavirus vaccine into the routine immunization program in Kenya has resulted in a notable decline in rotavirus and all-cause AGE hospitalizations in Central Kenya. This provides early evidence for public health policy makers in Kenya to support the sustained use of the rotavirus vaccine in routine immunizations.     

Incidence of rotavirus gastroenteritis hospitalizations and genotypes,before and five years after introducing universal immunization in Israel

BackgroundUncertainty exists about the sustainability of the reduction in rotavirus gastroenteritis (RVGE) following the introduction of rotavirus vaccines into national immunization programs, and on its potential impact on circulating genotypes. RotaTeq was introduced into the Israeli national immunization program in December 2010, and vaccination coverage is around 80%.AimsTo examine the change in incidence of RVGE hospitalization and rotavirus genotypes, during the five years after introduction of RotaTeq into the Israeli national immunization program.MethodsData were obtained prospectively on hospitalization of children aged 0–59 months due to acute gastroenteritis (N = 7346) from three hospitals in northern Israel. Stool samples were tested for rotavirus by immunochromatography. Rotavirus was genotyped (N = 506) by RT-PCR and/or sequencing.ResultsThe average incidence of RVGE hospitalization declined by 61.0% (95% CI 49.0–73.4%), from 5.6 per 1000 (95% CI 5.0–6.2) in the pre-universal immunization period (2008–2010) to 2.2 per 1000 (95% CI 1.8–2.5) during the universal immunization period (2012–2015), but yearly fluctuations were still observed.The most common genotypes in the pre-universal immunization period were G1P[8] (35.3%) followed by G2P[4] (15.5%), G3P[8] (8.8%), G4P[8] (4.3%) and G9P[8] (4.3%), and 19.5% were mixed infections. The dominance of G1P[8] continued into the universal immunization period (48.6%), followed by G3P[8] (21.5%), G9P[8] (15.9%) and G12P[8] (4.7%), while mixed rotavirus infections were no longer detected.ConclusionsUniversal immunization with RotaTeq in Israel was associated a sustained reduction in RVGE hospitalization. It is unclear whether changes in the circulating rotavirus genotypes are due to vaccine-induced selective pressure. Assessment of the long-term impact of rotavirus vaccination on the incidence of rotavirus gastroenteritis and continued strain surveillance is warranted.     

Early impact of rotavirus vaccination in children less than five years of age in Mozambique

BackgroundMozambique introduced rotavirus vaccine (Rotarix, GSK Biologicals) in the National Immunization Program in September 2015 with the objective of reducing the burden of total diarrheal disease and specifically severe rotavirus disease. This study aimed to evaluate the early impact of rotavirus vaccine in reducing all-cause diarrhea and rotavirus-specific hospitalizations.MethodsWe analysed stool specimens collected from children under five years old, between January 2014 and June 2017 within the National Surveillance for Acute Diarrhea. We compared annual changes in rotavirus positivity, median age of children hospitalized for rotavirus and the number of all-cause for diarrheal hospitalizations. Rotavirus detection was performed using enzyme immunoassay.ResultsDuring this period, 1296 samples were collected and analyzed. Rotavirus positivity before vaccine introduction was 40.2% (39/97) in 2014 and 38.3% (225/588) in 2015, then after vaccine introduction reduced to 12.2% and 13.5% in 2016 and 2017, respectively. The median age of children hospitalized for rotavirus was 9 and 11 months in 2014 and 2015 and 10 months in 2016 and 2017. Rotavirus hospitalizations exhibited a seasonal peak prior to vaccine introduction, between June and September in 2014 and 2015, coinciding with winter period in Mozambique. After vaccine introduction, the peak was delayed until August to December in 2016 and was substantially diminished. There was a reduction in all-cause acute diarrhea hospitalizations in children aged 0–11 months after vaccine introduction.ConclusionWe observed a reduction in rotavirus positivity and in the number of all-cause diarrhea hospitalizations after vaccine introduction. The data suggest rotavirus vaccine is having a positive impact on the control of rotavirus diarrheal disease in Mozambique.     

Evaluating the first introduction of rotavirus vaccine in Thailand: Moving from evidence to policy

BackgroundWe assessed the effectiveness and possible impact of introducing rotavirus vaccine into the routine immunization program.MethodsTwo provinces were selected for an observational study, one where vaccine was introduced and another where vaccine was not available. In these areas, two sub-studies were linked. The prospective cohort study enrolled children 2 month old and followed them to the age of 18 months to detect all diarrhea episodes. The hospital surveillance study enrolled all children up to age 5 hospitalized with diarrhea whose fecal samples were tested for rotavirus. Rates of rotavirus hospitalizations in older children who had not been vaccinated in both settings provided data to determine whether immunization had an indirect herd effect. The key endpoints for the study were both vaccine effectiveness (VE) based upon hospitalized rotavirus diarrhea and herd protection.FindingsFrom the cohort study, the overall VE for hospitalized rotavirus diarrhea was 88% (95%CI 76–94). Data from hospital surveillance indicated that for 2 consecutive years, the seasonal peak of rotavirus admissions was no longer present in the vaccinated area. Herd protection was observed among older children born before the rotavirus vaccine program was introduced, who experienced a 40–69% reduction in admission for rotavirus.ConclusionsRotavirus vaccine was highly effective in preventing diarrheal hospitalizations and in conferring herd protection among older children who had not been vaccinated.     

Predominance of unusual rotavirus G1P[6] strain in North India: An evidence from hospitalized children and adult diarrheal patients

Group A Rotavirus remains the leading cause of gastroenteritis in children and accounts for 0.2 million fatalities each year; out of which, approximately 47,100 deaths occur in India. In adults also, rotavirus is reported to be responsible for diarrhea severe enough to require hospitalizations. India has recently introduced rotavirus vaccine in the Universal Immunization Programme and Himachal Pradesh became the first Indian state to implement this project. This study is an attempt to provide the pre-vaccination data on rotavirus gastroenteritis burden and circulating genotypes in Himachal Pradesh, India. A total of 607 faecal specimens (247 children ≤ 5 years, 50 older children and 310 adults) from hospitalized diarrheal patients from Himachal Pradesh, India were screened for rotavirus using ELISA and RT-PCR. The positive samples were further G/P genotyped using semi-nested PCR. Rotavirus was detected in 25.2% and 28.3% of samples with ELISA and RT-PCR, respectively. In children, rotavirus frequency was significantly high with positivity in 49.0% cases whereas 14.0% adult samples have rotavirus in them. Genotyping of the positive samples revealed predominance of G1 (66.0%) and P[6] (66.7%) genotypes. The most common G and P combination was G1P[6] (62.8%) followed by G1P[8] (16.5%), G9P[6] (7.4%) and G12P[6] (5.0%). Molecular analysis reveals the belonging of P[6] strains in Lineage 1a. This pre-vaccination data on rotavirus prevalence and diversity would be helpful for assessing the affect of vaccination on the disease burden and its comparison with post-vaccination data of circulating genotypes would help in studying the effect on diversity of rotavirus strains possibly due to vaccine selection pressure.     

Changing molecular epidemiology of rotavirus infection after introduction of monovalent rotavirus vaccination in Scotland

BackgroundRotaviruses (RV) are the leading cause of gastroenteritis in children less than five years of age worldwide. Rotarix®, a live attenuated monovalent vaccine containing a RV strain of G1P[8] specificity has been included in the childhood immunisation schedule from June 2013 in Scotland. This study aimed to characterise the prevalent RV strains in Scotland before and after the introduction of the RV vaccine.MethodsRV positive faecal samples from Scottish virology laboratories covering the years 2012–2015 were genotyped. Viral RNA was extracted from faecal suspensions. VP7 and VP4 gene specific primers were used for multiplex hemi-nested PCRs and sequencing. Mann-Whitney U test and Chi-square test were used for statistical comparison.ResultsThere was a decrease in RV positive samples from the Scottish virology laboratories from 7409 samples in the pre-vaccination years (2009–2013) to 760 in 2014–2015, with an annual reduction of RV infections by 74.4% (RR-3.95; 95%-CI, 3.53–4.42, p < 0.001). 362 samples from the pre-vaccination period and 278 samples from the post-vaccination were genotyped. There was a drop in prevalence of G1P[8] strains (72.1%, 95%-CI, 67.42–76.33 to 15%, 95%-CI, 11.38–19.79) after introduction of the vaccine. In the post-vaccination period G2P[4] was the dominant strain in Scotland (21.9%, 95%-CI, 17.48–27.17) with increase in G9P[8] (12.9%, 95%-CI, 9.50–7.41), G12P[8] (12.2%, 95%-CI, 8.89–16.60) and G3P[8] (11.9%, 95%-CI, 8.58–16.20) infections. Phylogenetic analysis of the VP7 and VP4 genes showed no major differences between the pre and post-vaccination G1P[8] strains.ConclusionThis laboratory based surveillance study shows significant reduction in reported RV cases and a shift in proportion from G1P[8] to G2P[4] strains after introduction of RV vaccination in Scotland. The genotyping data from a subset of the total reported RV cases will be used to ascertain cross protection against strains and identify vaccine induced RV strain shifts in the years to come.     

A population based study comparing changes in rotavirus burden on the Island of Ireland between a highly vaccinated population and an unvaccinated population

BackgroundRotavirus infection is a leading cause of gastroenteritis in infants and children globally. Reductions in rotavirus activity have been observed following introduction of rotavirus vaccination programmes, however a reductions have also been reported in some unvaccinated countries.The Island of Ireland incorporates the two jurisdictions Northern Ireland (NI) and the Republic of Ireland (IE). Both have similarities in climate, demography, morbidity and mortality but distinct health administrations and vaccination policies. Rotarix was added to the childhood immunisation programme in NI on the 1 July 2013. IE have not introduced routine rotavirus vaccination to date.The aim of this population based ecological study was to evaluate the impact of the rotavirus vaccine on burden of rotavirus disease in NI, and to compare with IE as an unvaccinated control population. This will help determine if the changes seen were due to the rotavirus vaccine, or due to confounding factors.MethodsA number of population based measures of disease burden were compared in both jurisdictions pre-vaccine (six years; 2007/08–2012/13) and post-vaccine (two years; 2013/14–2014/15). The data sources included national rotavirus surveillance data based on laboratory reports/notifications; hospital admission data; and notifications of gastroenteritis in under 2 year olds.ResultsIn the post-vaccination period, rotavirus incidence in NI dropped by 54% while in IE it increased by 19% compared to the pre-vaccine period. Notifications of gastroenteritis in under 2 s in NI declined by 53% and hospital admissions in under 5 year olds in NI declined by 40% in the post vaccine period.ConclusionsThis natural experiment demonstrated a significant reduction in rotavirus disease activity post-vaccine introduction in NI with associated reductions in healthcare utilisation, with a concurrent increase in rotavirus disease activity in the non-vaccinated population in IE. These findings support rotavirus vaccination as an effective measure to reduce childhood morbidity.     

Rotavirus strain distribution in Ghana pre- and post- rotavirus vaccine introduction

BackgroundGhana introduced the monovalent rotavirus vaccine (Rotarix) into its national paediatric vaccination programme in May2012. Vaccine introduction was initiated nationwide and achieved >85% coverage within a few months. Rotavirus strain distribution pre- and post-RV vaccine introduction is reported.MethodsStool samples were collected from diarrhoeic children <5 years of age hospitalized between 2009 and 2016 at sentinel sites across Ghana and analyzed for the presence of group A rotavirus by enzyme immunoassay. Rotavirus strains were characterized by RT-PCR and sequencing.ResultsA total of 1363 rotavirus EIA-positive samples were subjected to molecular characterization. These were made up of 823 (60.4%) and 540 (39.6%) samples from the pre- and post-vaccine periods respectively. Rotavirus VP7 genotypes G1, G2 and G3, and VP4 genotypes P[6] and P[8] constituted more than 65% of circulating G and P types in the pre–vaccine period. The common strains detected were G1P[8] (20%), G3P[6] (9.2%) and G2P[6] (4.9%).During the post-vaccine period, G12, G1 and G10 genotypes, constituted more than 65% of the VP7 genotypes whilst P[6] and P[8] made up more than 75% of the VP4 genotypes. The predominant circulating strains were G12P[8] (26%), G10P[6] (10%) G3P[6] (8.1%) and G1P[8] (8.0%). We also observed the emergence of the unusual rotavirus strain G9P[4] during this period.ConclusionRotavirus G1P[8], the major strain in circulation during the pre-vaccination era, was replaced by G12P[8] as the most predominant strain after vaccine introduction. This strain replacement could be temporary and unrelated to vaccine introduction since an increase in G12 was observed in countries yet to introduce the rotavirus vaccine in West Africa. A continuous surveillance programme in the post-vaccine era is necessary for the monitoring of circulating rotavirus strains and the detection of unusual/emerging genotypes.