Acute gastroenteritis hospitalizations after implementation of universal mass vaccination against rotavirus

BackgroundEstonia implemented rotavirus universal mass vaccination (RV UMV) in July 2014. We aimed to describe changes in acute gastroenteritis (AGE) hospitalization during RV seasons before (2007–2013) and after (2015–2018) RV UMV and compare patient profile of hospitalized AGE patients aged 0–18 years during first two consecutive RV seasons 2015 vs 2016.MethodsWe described AGE hospitalization patterns pre-and post-vaccine era using Estonian Health Insurance Fund (HIF) database. During a two-year observational multicenter study in seven Estonian hospitals from 01st of February 2015 to 30th August 2016 we assessed patient profile of all patients who met pre-determined AGE criteria.ResultsIn post-vaccine era AGE hospitalization rate decreased from 10 to 8 per 1000 population (RR 0.81, 95% CI 0.79–0.83) compared to pre-vaccine era. Decreased RV seasonal activity, 81% (95% CI 77–84) and 55% (95% CI 52–58) reduction of rotavirus gastroenteritis (RVGE) hospitalization among age groups <1 and 1–4, respectively and upsurge of norovirus gastroenteritis (NoVGE) hospitalizations (RR = 1.8; 95% CI 1.6–1.9) was seen.In the multicenter observational study, among 2249 AGE patients hospitalized median age of RVGE patients increased from 2 to 3 years (p < 0.01) and duration of hospital stay decreased among RVGE, NoVGE and other GE patients during two consecutive RV seasons. According to Vesikari Clinical Severity Scoring System statistically significant change of severity score distribution in two RV seasons was seen (p < 0.001) with trend towards less severe AGE hospitalizations; 82.5% vs 70.5% severe cases in 2015 vs 2016, respectively.ConclusionRV UMV lead to immediate and sustainable reduction of hospitalizations due to RVGE in children aged <4 years and reduction of overall AGE accompanied with the decrease in the severity of hospitalized children.     

Impact of rotavirus vaccination on rotavirus hospitalizations in Taiwanese children

In 2006, two rotavirus vaccines were licensed in Taiwan but were not added to the national immunization schedule. National Health Insurance data from 2003 through 2017 were used to compare rotavirus-associated pediatric hospitalizations before and after vaccine introduction. Rotavirus hospitalization rates among children < 5 years of age significantly declined by 24% (95% confidence interval [CI] 23 – 25%) in post-vaccine compared to pre-vaccine rotavirus seasons. Rotavirus hospitalization rates declined by 42% (95% CI 39 – 44%) among infants < 12 months of age, and by 38% (95% CI 36 – 40%) among children 12 – 23 months of age. These findings suggest that, despite not being included in the national immunization schedule, rotavirus vaccines had a measurable impact on reducing rotavirus hospitalization burden among Taiwanese children.     

Detection of rotavirus before and after monovalent rotavirus vaccine introduction and vaccine effectiveness among children in mainland Tanzania

BackgroundMonovalent rotavirus vaccine (RV1) was introduced in Tanzania in January 2013 under the Reach Every Child initiative, to be given at ages 6 and 10 weeks. We used the sentinel hospital rotavirus surveillance system to examine the rotavirus detection rate before and after vaccine introduction and estimate vaccine effectiveness.MethodsBefore vaccine introduction, rotavirus surveillance was established at two mainland hospitals; children admitted for acute diarrhea were eligible for enrollment and stools were tested for rotavirus antigen. We compared the rotavirus positivity rate in the pre-vaccine period (Tanga Hospital, 2009 and 2011; Bugando Medical Centre, 2012) to that from post-introduction years, 2014–2015. In 2013, surveillance was established at 9 additional hospitals. We examined rotavirus positivity among infants at these sites for 2014–2015. We obtained vaccine records and calculated vaccine effectiveness at 3 sites using case-test-negative control design.ResultsAt Tanga Hospital, the rotavirus positivity rate among infants was 41% (102/251) pre-vaccine and 14% (28/197) in post-vaccine years (rate ratio: 0.35 [95% CI 0.22–0.54]). At Bugando, the positivity rate was 58% (83/143) pre-vaccine, and 18% (49/277) post-introduction (rate ratio 0.30 [95% CI 0.210.44]). Results were similar among children <5 years. At the new sites, the median site rotavirus positivity rate among infants was 26% in 2014 (range 19–44%) and 18% in 2015 (range 16–33%). The effectiveness of ≥1 RV1 dose against rotavirus hospitalization among children 5–23 months was 53% (95% CI: −14, 81), and 66% (95% CI: 9–87) against hospitalization with intravenous rehydration. Following introduction, peak rotavirus activity occurred later in the year and appeared more concentrated in time.ConclusionRotavirus surveillance data from Tanzania indicate that the rotavirus positivity rate among children hospitalized with diarrhea that were enrolled was substantially reduced after vaccine introduction. Low positivity rates among infants were detected at hospitals across the country. Overall, the data support that rotavirus vaccine has been successfully introduced and is effective in Tanzanian children.     

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.     

Impact of rotavirus vaccination on seizure hospitalizations in children: A systematic review

BackgroundPrevious studies found conflicting results about the effect of rotavirus (RV) vaccination on seizure hospitalizations in children younger than 5 years old.ObjectivesTo evaluate the evidence of the impact of RV vaccination on the prevention of seizure hospitalizations in children.MethodsA systematic review was conducted in the electronic database MEDLINE of all observational studies in children younger than 5 years old published since 2006. Two reviewers performed title/abstract, full-text review, and data extraction.ResultsThirteen studies met eligibility criteria. Nine studies reported a significant reduction in seizure hospitalizations upon RV vaccine introduction, three studies reported an absence of significant impact, and one study reported a significant rise in seizure hospitalization after the introduction of RV vaccines.LimitationsThe great variability between study designs, case definitions and potential biases prevent quantifying the impact of RV vaccination against seizure hospitalizations.ConclusionsRV vaccination might prevent seizure hospitalizations in children; however, robust, and well-designed studies are needed to better determine the strength of this association.     

Varicella and herpes zoster hospitalizations before and after implementation of one-dose varicella vaccination in Australia: an ecological study

Objective

To examine trends in varicella and herpes zoster (HZ) hospitalization following the availability and subsequent National Immunization Programme funding of one-dose varicella vaccination in Australia.

Methods

Varicella vaccination coverage for children born between 2001 and 2009 was obtained from the Australian Childhood Immunization Register. Principal or any coded varicella or HZ hospitalizations were retrieved from the national hospital morbidity database from 1998 to 2010. Trends in hospitalization rates in different age groups and indigenous status were assessed. Incidence rate ratios (IRR) were calculated between periods before and after implementation of immunization programme funding.

Findings

In the first year of the funded immunization programme, varicella vaccine coverage reached 75% in children aged 24 months and more than 80% in children aged 60 months. Compared with the pre-vaccine period, varicella hospitalization rates during the funded programme were significantly lower for age groups younger than 40 years; with the greatest reduction in children aged 18–59 months (IRR: 0.25; 95% confidence interval, CI: 0.22–0.29). Indigenous children had a higher varicella hospitalization rate compared with non-indigenous children before vaccine implementation (IRR: 1.9; 95% CI: 1.4–2.7), but afterwards reached equivalence (IRR: 1.1; 95% CI: 0.7–1.6). The age-standardized HZ hospitalization rate declined between the periods (IRR: 0.95; 95% CI: 0.92–0.97).

Conclusion

Rapid attainment of high coverage reduced varicella hospitalizations in the targeted age group, particularly for indigenous children, but also in non-targeted age groups, with no increase in HZ hospitalizations. This suggests high one-dose varicella vaccine coverage can have a substantial impact on severe disease.     

Racial disparities in diarrhea-associated hospitalizations among children in five US States,before and after introduction of rotavirus vaccine

Racial differences in diarrheal disease have not been systematically examined, and the impact of rotavirus vaccine on these differences has not been assessed. We compared diarrhea-associated hospitalizations by race/ethnicity among children <5 years pre- (2000–2006) and post- (2007 and 2008) rotavirus vaccine introduction in five US states. Pre-vaccine hospitalization rates were greater among whites versus blacks and Hispanics. However, black (versus non-black) infants <6 months and white (versus non-white) children ≥1 year had higher rates. In 2008, racial disparities for children 12–35 months resolved, but higher hospitalization rates among black infants <6 months persisted, highlighting the need for timely vaccination.     

Impact of non-routine rotavirus vaccination on hospitalizations for diarrhoea and rotavirus infections in Spain

This study shows hospital discharges related to all-cause diarrhoea and rotavirus infection in children up to five years of age from 2005 to 2009 in Spain. Rotavirus vaccines have been available in Spain since late 2006 and early 2007. They are neither funded nor reimbursed by the National Health Care System. However, they are recommended by the Spanish Association of Pediatricians and prescribed by paediatricians. The vaccination coverage was 17% in 2007, 35% in 2008 and 38% in 2009. Among a total of 111,738 hospitalizations recorded, 24% (N = 26,500) were coded as rotavirus and 14% (N = 16,217) as diarrhoea of undetermined aetiology. The overall annual incidence of hospitalization was 991,235 and 144 per 100,000 children up to five years of age for all-causes diarrhoea, rotavirus infection and diarrhoea of undetermined aetiology respectively. The annual rate significantly decreased during the study period.     

Impact of rotavirus vaccination on hospitalizations for rotavirus diarrhea: the IVANHOE study

The aim of the IVANHOE study was to determine the real-world impact of the rotavirus vaccine, controlling for epidemic-to-epidemic variation in disease burden.A population-based prospective cohort study was conducted in Brest City and 7 suburban districts (CUB area), North-western Brittany, France (210,000 inhabitants; 5500 births per year). The vaccination program started in May 2007 for a 2-year period for all infants born in the Brest birth zone through pediatricians, public outpatient clinics and general practitioners. To determine vaccine impact we monitored trends in hospitalizations for rotavirus-specific diarrhea using an active hospital-based surveillance system initiated 5 years before vaccine introduction. The number of hospitalizations for rotavirus-specific diarrhea during the 2008/2009 epidemic in infants less than 2 years of age whose parents lived within the CUB area was modelled as a function of (1) the number of hospitalizations in infants 2-5 years of age to control for epidemic-to-epidemic variation and (2) vaccine introduction. A total of 4684 infants received at least one dose. Of these, 2635 lived within the CUB area. Vaccine coverage for a complete schedule in the CUB area was 47.1%. Poisson modelling revealed a reduction by a factor of 2.04 (1.56-2.66) in the number of hospitalizations during the last epidemic season (2008/2009), the number of observed cases being equal to 30, against an expected number of 61. Relative risk reduction for hospitalizations for rotavirus diarrhea was 98% (95% CI: 83-100%). We observed a noticeable impact of vaccination on rotavirus diarrhea hospitalizations within 2 years of vaccine introduction integrating for the first time rotavirus epidemics variation. The trial is registered with ClinicalTrials.gov, number, NCT00740935.     

Impact and effectiveness of monovalent rotavirus vaccine in Tajik children

BackgroundIn 2015, Tajikistan became the second country in Central Asia to introduce rotavirus vaccine into its national immunization program. Before vaccine introduction, rotavirus was estimated to cause > 40% of pediatric diarrhea hospitalizations in Tajikistan. We aimed to assess the impact of rotavirus vaccine introduction on rotavirus disease burden and estimate rotavirus vaccine effectiveness (VE).MethodsUsing surveillance data from 2013 through 2019, we examined trends in monthly hospital admissions among children < 5 years old, before and after rotavirus vaccine introduction. Poisson regression was used to quantify decreases. VE was estimated using a test-negative case control design, with data from admissions during 2017 – 2019. Immunization records were obtained from clinics.ResultsAmong enrolled children, rotavirus positivity declined from 42% to 25% in the post-vaccine introduction period, a decrease of 41% (95% Confidence Interval [CI]: 36 – 45%). Declines were greatest in children < 12 months of age. Estimated VE of a complete course of rotavirus vaccine was 55% (95% CI: 21 – 73%) among children 5 – 59 months of age and 64% (95% CI: 36 – 80%) among children 5 – 23 months of age. VE point estimates were higher among children receiving both doses of rotavirus vaccine non-concurrently with OPV and among children receiving their first dose of rotavirus vaccine at 4 – 11 months of age, but CIs were wide and overlapping.ConclusionsOur data demonstrate that rotavirus vaccine introduction was associated with a substantial reduction in pediatric rotavirus hospitalization burden in Tajikistan, and that rotavirus vaccination is effective in Tajik children.     

Effectiveness of monovalent and pentavalent rotavirus vaccines in Japanese children

BackgroundRotavirus (RV) vaccination has been available in Japan since November 2011, but is not yet part of Japan’s national immunisation programs. There are insufficient data on vaccine effectiveness (VE) among Japanese children.MethodsBetween the months of January and May in 2014 and 2015, we conducted active surveillance of gastroenteritis among children at 14 medical facilities. Rectal swabs from all patients with diarrhoea or vomiting were tested for RV by immunochromatography, and positive specimens were genotyped. Demographic data and immunisation records were obtained from a questionnaire completed by their parents/guardians or medical records. A test-negative case-control design was used to examine vaccine effectiveness (VE) using unconditional logistic regression analysis adjusted for possible confounding factors.ResultsAmong the 1519 eligible subjects (children with acute gastroenteritis symptoms aged ≥2 months to <3 y visiting medical facilities) recruited, 487 cases and 925 controls were enrolled. Cases had more severe symptoms than controls, requiring more intensive treatment, including intravenous rehydration or hospitalisation. VE against all rotavirus gastroenteritis (RVGE) was 80.0% (95% confidence interval [CI], 72.8–85.5%), and VEs against RV1 and RV5 were similar, at 80.6% (95%CI, 70.7–87.1%) for RV1 and 80.4% (95% CI, 69.1–87.6%) for RV5. Although VEs of both vaccines decreased with age, VEs against all RVGE were >70% up to 2 years after vaccination. VEs increased with severity of RVGE, and VE against severe RVGE, requiring intravenous rehydration or hospitalisation, was 97.3% (95% CI, 88.8–99.3%). VEs of RV1 and RV5 against G1P[8] and G2P[4] were comparable, at RV1, 89.8% (95% CI, 78.2–95.5%) and 78.3% (95% CI, 23.6–93.8%); and RV5, 85.8% (95% CI, 72.8–92.6%) and 88.1% (95% CI, 10.1–98.4%), respectively.ConclusionsRotavirus vaccines were effective in preventing mild to severe RVGE, irrespective of vaccine type, time since vaccination, or RV genotype.     

Trends in diarrhea hospitalizations among infants at three hospitals in Tanzania before and after rotavirus vaccine introduction

BackgroundThe Tanzania Ministry of Health introduced monovalent human rotavirus vaccine in January 2013, to be administered at ages 6 and 10 weeks. Data suggest there was high vaccine uptake. We used hospital ward registers from 3 hospitals to examine trends in diarrhea hospitalizations among infants before and after vaccine introduction.MethodsWard registers from Dodoma Regional Referral Hospital (Central Tanzania), and two hospitals in Mbeya (Southwest area), Mbeya Zonal Referral Hospital and Mbalizi Hospital, were used to tally admissions for diarrhea among children by age group, month and year. Rotavirus surveillance had started at these hospitals in early 2013; the proportion of infants enrolled and rotavirus-EIA positive were examined by month to determine peak periods of rotavirus disease post-vaccine introduction.ResultsRegisters were available for 2–4 prevaccine years and 2–3 post introduction years. At Dodoma Regional Referral Hospital, compared with the mean of 2011 and 2012, diarrhea hospitalizations among infants were 26% lower in 2015 and 58% lower in 2016. The diarrhea peak shifted later in the year first by 1 and then by 2–3 months from prevaccine. At the Mbeya hospitals, the number of diarrhea admissions in prevaccine period varied substantially by year. At Mbeya Referral Hospital, diarrhea hospitalizations among infants were lower by 25–37% in 2014 and 11–26% in 2015, while at Mbalizi Hospital, these hospitalizations were 4% lower in 2014 and 14% higher in 2015. Rotavirus testing data demonstrated a lowering of the prevaccine peak, a shift in timing of the peak months and indicated that other diarrheal peaks in post-introduction years were not due to rotavirus.ConclusionsIn this ecological evaluation, total diarrhea hospitalizations among infants were lower (≥25% lower in ≥1 year) following introduction in 2 of 3 hospitals. There are challenges in using ward registers to ascertain possible impact of rotavirus vaccine introduction on trends in hospitalizations for treatment of all diarrheal illness.     

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.     

Genotype distribution of Group A rotavirus in children before and after massive vaccination in Latin America and the Caribbean: Systematic review

BackgroundDuring the last decade, most of Latin American and the Caribbean (LAC) countries have implemented oral live rotavirus vaccines in their national vaccination programs with remarkable results. However, it has been suggested that massive vaccination could lead to the replacement of circulating genotypes or the emergence of new variants or neutralizing antibodies escape mutants, which may reduce the effectiveness of the vaccine. The objective was to analyze the genetic diversity of Group A rotavirus before and after the introduction of universal vaccination in LAC.MethodsWe conducted a systematic review of studies published in PubMed, Scielo and LILACS. There were considered only LAC countries with rotavirus massive vaccination strategy which had described circulating genotypes data in children under 5 years of age, either for surveillance or vaccine effectiveness purposes, from 2001 to 2017. Systematic review stages were carried out following the recommendations of PRISMA.ResultsOf the 18 countries that included any of the two licensed rotavirus vaccines in their national schedules since 2006, only 7 (~39%) presented studies of RVA genetic diversity before and after implementation, and met the inclusion criteria. Four of them (Argentina, Brazil, Colombia and Nicaragua) experienced a rapid switch from Wa-like to DS-1-like strains. Also, G1P[8] association, considered the most predominant worldwide in the pre-vaccination era, decreased significantly and was only frequently detected in Venezuela and Nicaragua. No defined pattern of emergence at high frequencies of unusual associations was observed in the post vaccination period, except for some evidence of G9P[4] in Colombia, G3P[6] and G1P[4] in Nicaragua.ConclusionsEven though the evidence shows a DS-1-like change trend, data from studies conducted in Latin America and the Caribbean are diverse and still not sufficient to assess the impact of vaccines on viral ecology or if genetic diversity is influenced by natural mechanisms of fluctuation.     

Knowledge,attitudes, beliefs,and behaviors of parents and healthcare providers before and after implementation of a universal rotavirus vaccination program

ObjectiveIn Canada, rotavirus vaccine is recommended for all infants, but not all provinces/territories have publicly funded programs. We compared public and healthcare provider (HCP) knowledge, attitudes, beliefs, and behaviors in a province with a public health nurse-delivered, publicly funded rotavirus vaccination program to a province with a publicly funded, physician-delivered program. A third province with no vaccination program acted as a control.DesignInformation about knowledge, attitudes, beliefs, and behaviors of parents whose children were eligible for the universal program and healthcare providers responsible for administering the vaccine were collected through the use of two validated surveys distributed in public health clinics, physicians’ offices, and via e-mail. Early and postvaccine-program survey results were compared.ResultsA total of 722 early implementation and 709 postimplementation parent surveys and 180 early and 141 postimplementation HCP surveys were analyzed. HCP and public attitudes toward rotavirus vaccination were generally positive and didn’t change over time. More parents postprogram were aware of the NACI recommendation and the vaccination program and reported that their healthcare provider discussed rotavirus infection and vaccine with them. Prior to the program across all sites, more physicians than nurses were aware of the national recommendation regarding rotavirus vaccine. In the postprogram survey, however, more nurses were aware of the national recommendation and their provincial universal rotavirus vaccination program. Nurses had higher knowledge scores than physicians in the postprogram survey (p < 0.001). Parents of young infants were also more knowledgeable about rotavirus and rotavirus vaccine in the two areas where universal programs were in place (p < 0.001).ConclusionsImplementation of a universal rotavirus vaccination program was associated with an increase in knowledge and more positive attitudes toward rotavirus vaccine amongst parents of eligible infants. Nurses involved in a public health-delivered vaccination program were more knowledgeable and had more positive attitudes toward the vaccine than physicians in a jurisdiction where vaccine was physician-delivered.     

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.     

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.     

The risk of intussusception following monovalent rotavirus vaccination in England: A self-controlled case-series evaluation

ObjectiveTo investigate the risk of intussusception after monovalent rotavirus vaccine (RV1) given to infants aged 2 and 3 months in England.MethodsHospital Episode Statistics (HES) were used to identify infants aged 48–183 days admitted between 11/03/2013 and 31/10/2014 with intussusception. Diagnosis was confirmed from medical records and HES procedure codes. Vaccination status was obtained from general practitioners. The risk of admission within 1–7 and 8–21 days of vaccination was analysed using the self-controlled case-series (SCCS) method with age effect adjustment by including historical data before RVI introduction in July 2013.ResultsA total of 119 cases were identified during the study period and intussusception confirmed in 95 of whom 39 were vaccinated 1–21 days before onset. An increased relative incidence (RI) in this period was found, 4.53 (95% confidence interval 2.34–8.58) and 2.60 (1.43–4.81) respectively after the 1st and 2nd doses with an attributable risk of 1.91 and 1.49 per 100,000 doses respectively. The peak risk was 1–7 days after the first dose, RI 13.81 (6.44–28.32), with an estimated 93% of the 15 cases being vaccine-attributable. Mean interval between onset and admission, and clinical features were similar between vaccine-associated and background cases. Despite intussusception being a contraindication to rotavirus vaccination, 10 infants received a further dose; none had a recurrence. The RIs in a meta-analysis combing our results with Australia, Mexico, Brazil and Singapore using RV1, a 2, 4 month schedule and SCCS gave pooled RI estimates of 2.35 (1.45–3.8) and 1.77 (1.29–2.43) in the 21 day period after the 1st and 2nd doses, respectively. The earlier age at the 2nd dose in England did not affect the risk.ConclusionWe estimate that the RVI programme causes around 21 intussusception admissions annually in England but, since it prevents around 25,000 gastro-intestinal infection admissions, its benefit/risk profile remains strongly positive.