Safety and implementation of a phase 1 randomized GLA-SE-adjuvanted CH505TF gp120 HIV vaccine trial in newborns.

Background: The neonatal immune system is uniquely poised to generate broadly neutralizing antibodies (bnAbs) and thus infants are ideal for evaluating HIV vaccine candidates. We present the design and safety of a novel glucopyranosyl lipid A (GLA)-stable emulsion (SE) adjuvant admixed with a first-in-infant CH505 transmitter-founder (CH505TF) gp120 immunogen designed to induce precursors for bnAbs against HIV. Methods: HVTN 135 is a phase I randomized, placebo-controlled trial of CH505TF+GLA-SE or placebo. Healthy infants in South Africa aged ≤5 days, born to mothers living with HIV but HIV nucleic acid negative at birth were randomized to five doses of CH505TF + GLA-SE or placebo at birth and 8, 16, 32, and 54 weeks. Results: 38 infants (median age = 4 days; interquartile range 4, 4.75 days) were enrolled November 2020 to January 2022. Among 28 (10) infants assigned to receive CH505TF + GLA-SE (placebo), most (32/38) completed the 5-dose immunization series and follow-up (35/38). Solicited local and systemic reactions were more frequent in vaccine (8, 28.6% local; 16, 57.1% systemic) vs. placebo recipients (1, 10% local, p = 0.25; 4, 40.0% systemic, p = 0.38). All events were Grade 1 except two Grade 2 events (pain, lethargy). Serious vaccine-related adverse events were not recorded. Conclusions: This study illustrates the feasibility of conducting trials of novel adjuvanted HIV vaccines in HIV-exposed infants receiving standard infant vaccinations. The safety profile of the CH505TF + GLA-SE vaccine was reassuring. Trial registration: ClinicalTrials.gov NCT04607408. Funding: National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH).

Efficacy of Messenger RNA-1273 Against Severe Acute Respiratory Syndrome Coronavirus 2 Acquisition in Young Adults From March to December 2021.

Background: The efficacy of messenger RNA (mRNA)-1273 against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is not well defined, particularly among young adults. Methods: Adults aged 18-29 years with no known history of SARS-CoV-2 infection or prior vaccination for coronavirus disease 2019 (COVID-19) were recruited from 44 US sites from 24 March to 13 September 2021 and randomized 1:1 to immediate vaccination (receipt of 2 doses of mRNA-1273 vaccine at months 0 and 1) or the standard of care (receipt of COVID-19 vaccine). Randomized participants were followed up for SARS-CoV-2 infection measured by nasal swab testing and symptomatic COVID-19 measured by nasal swab testing plus symptom assessment and assessed for the primary efficacy outcome. A vaccine-declined observational group was also recruited from 16 June to 8 November 2021 and followed up for SARS-CoV-2 infection as specified for the randomized participants. Results: The study enrolled 1149 in the randomized arms and 311 in the vaccine-declined group and collected >122 000 nasal swab samples. Based on randomized participants, the efficacy of 2 doses of mRNA-1273 vaccine against SARS-CoV-2 infection was 52.6% (95% confidence interval, -14.1% to 80.3%), with the majority of infections due to the Delta variant. Vaccine efficacy against symptomatic COVID-19 was 71.0% (95% confidence interval, -9.5% to 92.3%). Precision was limited owing to curtailed study enrollment and off-study vaccination censoring. The incidence of SARS-CoV-2 infection in the vaccine-declined group was 1.8 times higher than in the standard-of-care group. Conclusions: mRNA-1273 vaccination reduced the incidence of SARS-CoV-2 infection from March to September 2021, but vaccination was only one factor influencing risk. Clinical Trials Registration: NCT04811664.

Impact and effectiveness of Rotavin-M1 under conditions of routine use in two provinces in Vietnam, 2016-2021, an observational and case-control study.

Background: Half of diarrhea hospitalizations in children aged <5 years in Vietnam are due to rotavirus. Following introduction of a locally developed and licensed oral rotavirus vaccine, Rotavin-M1, into the routine immunization program in two Vietnamese provinces, Nam Dinh and TT Hue, we describe changes in rotavirus positivity among children hospitalized for diarrhea and calculate vaccine effectiveness against moderate-to-severe rotavirus hospitalizations. Methods: Active rotavirus surveillance among children <5 years began in December 2016 at sentinel hospitals in districts where rotavirus vaccine was introduced in December 2017. To estimate reductions in rotavirus detection, we calculated risk ratios comparing rotavirus positivity pre- and post-vaccine introduction. We used a test-negative case-control design to calculate vaccine effectiveness. Findings: From December 2016 to May 2021, 7228 children <5 years hospitalized for diarrhea were enrolled. Following introduction, Rotavin-M1 coverage was 77% (1066/1377) in Nam Dinh and 42% (203/489) in TT Hue. In Nam Dinh, rotavirus positivity among children <5 years significantly declined by 40.6% (95% CI: 34.8%-45.8%) during the three-year post-vaccine introduction period. In TT Hue, no change in rotavirus positivity was observed. Among children aged 6-23 months, a 2-dose series of Rotavin-M1 was 57% (95% CI: 39%-70%) effective against moderate-to-severe rotavirus hospitalizations. Interpretation: Higher vaccination coverage in Nam Dinh than TT Hue likely contributed to substantial declines in rotavirus positivity observed in Nam Dinh following rotavirus vaccine introduction. Robust vaccine effectiveness was observed through the second year of life. National rotavirus vaccine introduction with high coverage may have substantial impact on reducing rotavirus disease burden in Vietnam. Funding: Bill and Melinda Gates Foundation.

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.

Effect of Bamlanivimab vs Placebo on Incidence of COVID-19 Among Residents and Staff of Skilled Nursing and Assisted Living Facilities: A Randomized Clinical Trial.

Importance: Preventive interventions are needed to protect residents and staff of skilled nursing and assisted living facilities from COVID-19 during outbreaks in their facilities. Bamlanivimab, a neutralizing monoclonal antibody against SARS-CoV-2, may confer rapid protection from SARS-CoV-2 infection and COVID-19. Objective: To determine the effect of bamlanivimab on the incidence of COVID-19 among residents and staff of skilled nursing and assisted living facilities. Design, Setting, and Participants: Randomized, double-blind, single-dose, phase 3 trial that enrolled residents and staff of 74 skilled nursing and assisted living facilities in the United States with at least 1 confirmed SARS-CoV-2 index case. A total of 1175 participants enrolled in the study from August 2 to November 20, 2020. Database lock was triggered on January 13, 2021, when all participants reached study day 57. Interventions: Participants were randomized to receive a single intravenous infusion of bamlanivimab, 4200 mg (n = 588), or placebo (n = 587). Main Outcomes and Measures: The primary outcome was incidence of COVID-19, defined as the detection of SARS-CoV-2 by reverse transcriptase-polymerase chain reaction and mild or worse disease severity within 21 days of detection, within 8 weeks of randomization. Key secondary outcomes included incidence of moderate or worse COVID-19 severity and incidence of SARS-CoV-2 infection. Results: The prevention population comprised a total of 966 participants (666 staff and 300 residents) who were negative at baseline for SARS-CoV-2 infection and serology (mean age, 53.0 [range, 18-104] years; 722 [74.7%] women). Bamlanivimab significantly reduced the incidence of COVID-19 in the prevention population compared with placebo (8.5% vs 15.2%; odds ratio, 0.43 [95% CI, 0.28-0.68]; P < .001; absolute risk difference, -6.6 [95% CI, -10.7 to -2.6] percentage points). Five deaths attributed to COVID-19 were reported by day 57; all occurred in the placebo group. Among 1175 participants who received study product (safety population), the rate of participants with adverse events was 20.1% in the bamlanivimab group and 18.9% in the placebo group. The most common adverse events were urinary tract infection (reported by 12 participants [2%] who received bamlanivimab and 14 [2.4%] who received placebo) and hypertension (reported by 7 participants [1.2%] who received bamlanivimab and 10 [1.7%] who received placebo). Conclusions and Relevance: Among residents and staff in skilled nursing and assisted living facilities, treatment during August-November 2020 with bamlanivimab monotherapy reduced the incidence of COVID-19 infection. Further research is needed to assess preventive efficacy with current patterns of viral strains with combination monoclonal antibody therapy. Trial Registration: ClinicalTrials.gov Identifier: NCT04497987.

An immunization program for US-bound refugees: Development, challenges, and opportunities 2012-present.

BACKGROUND: US-bound refugees undergo required health assessments overseas to identify and treat communicable diseases of public health significance-such as pulmonary tuberculosis-before migration. Immunizations are not required, leaving refugees at risk for vaccine-preventable diseases. In response, the US Centers for Disease Control and Prevention and the US Department of State developed and co-funded a global immunization program for US-bound refugees, implemented in 2012 in collaboration with the International Organization for Migration. METHODS: We describe the Vaccination Program for US-bound Refugees, including vaccination schedule development, program implementation and procedures, and responses to challenges. We estimate 2019 immunization coverage rates using the number of age-eligible refugees who received ≥1 dose of measles-containing vaccine during overseas health assessment, and calculated hepatitis B infection prevalence using hepatitis B surface antigen testing results. We report descriptive data on adverse events following immunization. RESULTS: By September 2019, the program was active in >80 countries on five continents. Nearly 320,000 examined refugees had ≥1 documented vaccine doses since program inception. During federal fiscal year 2019, 95% of arriving refugees had ≥1 documented measles-containing vaccine. The program's immunization schedule included eleven vaccines preventing fourteen diseases. In 2015-2019, only two vaccine preventable disease-associated refugee group travel cancellations occurred, compared to 2-8 cancellations annually prior to program initiation. To maintain uniform standards, dedicated staff and program-specific protocols for vaccination and monitoring were introduced. CONCLUSIONS: An overseas immunization program was successfully implemented for US-bound refugees. Due to reductions in refugee movement cancellation, lower cost of immunization overseas, and likely reductions in vaccine preventable disease-associated morbidity, we anticipate significant cost savings. Although maintaining uniform standards across diverse settings is challenging, solutions such as introduction of dedicated staff, protocol development, and ongoing technical support have ensured program cohesion, continuity, and advancement. Lessons learned can benefit similar programs implemented in the migration setting.

Infectious Etiologies of Intussusception Among Children <2 Years Old in 4 Asian Countries.

BACKGROUND: The etiology of intussusception, the leading cause of bowel obstruction in infants, is unknown in most cases. Adenovirus has been associated with intussusception and slightly increased risk of intussusception with rotavirus vaccination has been found. We conducted a case-control study among children <2 years old in Bangladesh, Nepal, Pakistan, and Vietnam to evaluate infectious etiologies of intussusception before rotavirus vaccine introduction. METHODS: From 2015 to 2017, we enrolled 1-to-1 matched intussusception cases and hospital controls; 249 pairs were included. Stool specimens were tested for 37 infectious agents using TaqMan Array technology. We used conditional logistic regression to estimate odds ratio (OR) and 95% confidence interval (CI) of each pathogen associated with intussusception in a pooled analysis and quantitative subanalyses. RESULTS: Adenovirus (OR, 2.67; 95% CI, 1.75-4.36) and human herpes virus 6 (OR, 3.50; 95% CI, 1.15-10.63) were detected more frequently in cases than controls. Adenovirus C detection <20 quantification cycles was associated with intussusception (OR, 18.59; 95% CI, 2.45-140.89). Wild-type rotavirus was not associated with intussusception (OR, 1.07; 95% CI, 0.52-2.22). CONCLUSIONS: In this comprehensive evaluation, adenovirus and HHV-6 were associated with intussusception. Future research is needed to better understand mechanisms leading to intussusception, particularly after rotavirus vaccination.

Nutritional profile of Syrian refugee children before resettlement.

BACKGROUND: The year 2015 marked the highest number of refugees globally and included record numbers of Syrians moving to neighboring countries. Half of the Syrians were children aged ≤18 years. Our study sought to examine undernutrition and overnutrition among a group of Syrian refugee children who underwent medical screening by IOM for resettlement. METHODS: This is a retrospective review of Syrian refugee children aged 6 to 59 months from January 1, 2015 to December 31, 2016. The World Health Organization (WHO) Stata package computed Z-scores based on available weight and height data. Prevalence estimates of undernutrition (wasting and stunting) and overnutrition (overweight and obesity) were made using WHO standards. Multivariate analysis was used to determine the factors associated with wasting, stunting, and overnutrition, adjusting for age, sex, family size, and country of health assessment. RESULTS: A total of 14,552 Syrian refugee children aged 6 to 59 months underwent health assessments in Jordan (43·1%), Lebanon (38·8%), Turkey (7·0%), Greece (6·7%), Egypt (2·4%), and Iraq (2·1%). Overall, this group of Syrian refugee children had a low prevalence of wasting (< 5%) and stunting (< 10%), and high prevalence of overweight or obese (10.6%). Differences were observed in the prevalence of wasting by country of health assessment. In the multiple regression analysis, the prevalence of stunting and overnutrition decreased with increasing age, and being male was associated with overnutrition but not wasting and stunting. CONCLUSIONS: Findings revealed an overall low prevalence of undernutrition among this group of Syrian children assessed, although prevalence varied by age group. This low prevalence may reflect the effectiveness, as well as expose possible gaps, of refugee nutrition programs or interventions in countries of asylum. Further studies are recommended to evaluate other possible contributors to malnutrition in this refugee group.

Global impact of rotavirus vaccine introduction on rotavirus hospitalisations among children under 5 years of age, 2008-16: findings from the Global Rotavirus Surveillance Network.

BACKGROUND: Rotavirus vaccine use in national immunisation programmes has led to declines in hospital admissions for rotavirus gastroenteritis among children; however, the global impact of rotavirus vaccine introduction has not been described using primary data. We describe the impact of rotavirus vaccine introduction on admissions for acute rotavirus gastroenteritis in primarily low-income and middle-income countries, using 9 years of data from the WHO-coordinated Global Rotavirus Surveillance Network (GRSN). METHODS: Between Jan 1, 2008, and Dec 31, 2016, children younger than 5 years of age who were admitted to hospital with acute gastroenteritis were prospectively enrolled in GRSN sites. We included sites that enrolled children and collected stool specimens monthly and tested at least 100 specimens annually in the impact analysis, with a separate analysis taking into account site continuity. We compared proportions of acute gastroenteritis cases positive for rotavirus in the pre-vaccine and post-vaccine periods and calculated mean proportion changes for WHO regions, with 95% CIs; these findings were then compared with interrupted time series analyses. We did further sensitivity analyses to account for rotavirus vaccination coverage levels and sites that collected specimens for at least 11 months per year and tested at least 80 specimens per year. We also analysed the age distribution of rotavirus-positive cases before and after vaccine introduction. FINDINGS: 403 140 children younger than 5 years of age admitted to hospital with acute gastroenteritis from 349 sites in 82 countries were enrolled over the study period, of whom 132 736 (32·9%) were positive for rotavirus. We included 305 789 children from 198 sites in 69 countries in the impact analysis. In countries that had not introduced rotavirus vaccine in their national immunisation programmes, rotavirus was detected in 38·0% (95% CI 4·8-73·4) of admissions for acute gastroenteritis annually whereas in those that have introduced the vaccine, rotavirus was detected in 23·0% (0·7-57·7) of admissions for acute gastroenteritis, showing a 39·6% (35·4-43·8) relative decline following introduction. Interrupted time series analyses confirmed these findings. Reductions by WHO regions ranged from 26·4% (15·0-37·8) in the Eastern Mediterranean Region to 55·2% (43·0-67·4) in the European Region and were sustained in nine countries (contributing up to 31 sites) for 6-10 years. The age distribution of children with rotavirus gastroenteritis shifted towards older children after rotavirus vaccine introduction. INTERPRETATION: A significant and sustained reduction in the proportion of hospital admissions for acute gastroenteritis due to rotavirus was seen among children younger than 5 years in GRSN sites following rotavirus vaccine introduction. These findings highlight the need to incorporate rotavirus vaccines into immunisation programmes in countries that have not yet introduced them and underline the importance of high-quality surveillance. FUNDING: The GRSN receives funding from Gavi, the Vaccine Alliance and the US Centers for Disease Control and Prevention. No specific funding was provided for this Article.

Prevalence of Tuberculosis Disease Among Adult US-Bound Refugees with Chronic Kidney Disease.

The association between chronic kidney disease (CKD) and tuberculosis disease (TB) has been recognized for decades. Recently CKD prevalence is increasing in low- to middle-income countries with high TB burden. Using data from the required overseas medical exam and the recommended US follow-up exam for 444,356 US-bound refugees aged ≥ 18 during 2009-2017, we ran Poisson regression to assess the prevalence of TB among refugees with and without CKD, controlling for sex, age, diabetes, tobacco use, body mass index ( kg/m2), prior residence in camp or non-camp setting, and region of birth country. Of the 1117 (0.3%) with CKD, 21 (1.9%) had TB disease; of the 443,239 who did not have CKD, 3380 (0.8%) had TB. In adjusted analyses, TB was significantly higher among those with than without CKD (prevalence ratio 1.93, 95% CI: 1.26, 2.98, p < 0.01). Healthcare providers attending to refugees need to be aware of this association.

Monovalent Rotavirus Vaccine Effectiveness Against Rotavirus Hospitalizations Among Children in Zimbabwe.

BACKGROUND: Rotavirus is a leading cause of mortality among children <5 years old. We evaluated monovalent rotavirus vaccine effectiveness (VE) under conditions of routine use at 2 surveillance sites in Harare, Zimbabwe, after vaccine introduction in May 2014. METHODS: Children aged <5 years hospitalized or treated in the accident and emergency department (A&E) for acute watery diarrhea were enrolled for routine surveillance. Copies of vaccination cards were collected to document vaccination status. Among children age-eligible to receive rotavirus vaccine, we estimated VE, calculated as 1 - odds ratio, using a test-negative case-control design. RESULTS: We included 903 rotavirus-positive cases and 2685 rotavirus-negative controls in the analysis; 99% had verified vaccination status. Rotavirus-positive children had more severe diarrhea than rotavirus-negative children; 61% of cases and 46% of controls had a Vesikari score ≥11 (P < .01). Among cases and controls, 31% and 37%, respectively, were stunted for their age (P < .01). Among children 6-11 months old, adjusted 2-dose VE against hospitalization or treatment in A&E due to rotavirus of any severity was 61% (95% confidence interval [CI], 21%-81%) and 68% (95% CI, 13%-88%) against severe rotavirus disease. Stratified by nutritional status, adjusted VE was 45% (95% CI, -148% to 88%) among stunted infants and 71% (95% CI, 29%-88%) among infants with a normal height for age. CONCLUSIONS: Monovalent rotavirus vaccine is effective in preventing hospitalizations due to severe rotavirus diarrhea among infants in Zimbabwe, providing additional evidence for countries considering rotavirus vaccine introduction that live, oral rotavirus vaccines are effective in high-child-mortality settings.

Preparing for safety monitoring after rotavirus vaccine introduction - Assessment of baseline epidemiology of intussusception among children <2 years of age in four Asian countries.

Intussusception is the invagination of one segment of the bowel into a distal segment, characterized by symptoms of bloody stool, vomiting, and abdominal pain. Previous studies have found regional differences in incidence but the etiology of most intussusception cases is unknown. Rotavirus vaccines were associated with a slightly of increased risk of intussusception in post-licensure evaluations in high- and middle-income countries, but not in low income African countries. To describe the baseline epidemiology of intussusception in young children prior to rotavirus vaccine implementation, active sentinel hospital surveillance for intussusception in children < 2 years of age was conducted in 4 low income Asian countries (Bangladesh, Nepal, Pakistan and Vietnam). Over a 24-month period, 15 sites enrolled 1,415 intussusception cases, of which 70% were enrolled in Vietnam. Overall, 61% of cases were male and 1% (n = 16) died, ranging from 8% in Pakistan to 0% in Vietnam. The median age of cases enrolled ranged from 6 months in Bangladesh and Pakistan to 12 months in Vietnam. The proportion of cases receiving surgical management was 100% in Bangladesh, 88% in Pakistan, 61% in Nepal, and 1% in Vietnam. The high proportion of males and median age of cases around 6 months of age found in this regional surveillance network are consistent with previous descriptions of the epidemiology of intussusception in these countries and elsewhere. Differences in management and the fatality rate of cases between the countries likely reflect differences in access to healthcare and availability of diagnostic modalities. These baseline data will be useful for post-rotavirus vaccine introduction safety monitoring.

Burden of Severe Norovirus Disease in Taiwan, 2003-2013.

Background: Despite the increasingly recognized role of norovirus in global acute gastroenteritis (AGE), specific estimates of the associated disease burden remain sparse, primarily due to limited availability of sensitive norovirus diagnostics in the clinical setting. We sought to estimate the incidence of norovirus-associated hospitalizations by age group in Taiwan using a previously developed indirect regression method. Methods: AGE-related hospitalizations in Taiwan were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes abstracted from a national database; population data were provided from the Department of Household Registration Affairs. Population and hospitalizations were aggregated by month and year (July 2003-June 2013) and grouped by age: <5 years, 5-19 years, 20-64 years, and ≥65 years. Monthly counts of cause-unspecified AGE hospitalizations were modeled as a function of counts of known causes, and the residuals were then analyzed to estimate norovirus-associated hospitalizations. Results: Over the study period, an annual mean of 101400 gastroenteritis-associated hospitalizations occurred in Taiwan (44 per 10000 person-years), most of which (83%) had no specified cause. The overall estimated rate of norovirus-associated hospitalizations was 6.7 per 10000 person-years, with the highest rates in children aged <5 years (63.7/10000 person-years). Predicted norovirus peaked in 2006-2007 and 2012-2013. Conclusions: Our study is one of the first to generate a population-based estimate of severe norovirus disease incidence in Asia, and highlights the large burden of norovirus in Taiwan, particularly in children. Predicted peak norovirus seasons coincided with the emergence of new strains and resulting pandemics, supporting the validity of the estimates.

Distribution of rotavirus genotypes associated with acute diarrhoea in Zimbabwean children less than five years old before and after rotavirus vaccine introduction.

BACKGROUND: Sentinel surveillance for diarrhoea is important to monitor changes in rotavirus epidemiological trends and circulating genotypes among children under 5 years before and after vaccine introduction. The Zimbabwe Ministry of Health and Child Care introduced rotavirus vaccine in national immunization program in May 2014. METHODS: Active hospital-based surveillance for diarrhoea was conducted at 3 sentinel sites from 2008 to 2016. Children aged less than 5 years, who presented with acute gastroenteritis as a primary illness and who were admitted to a hospital ward or treated at the emergency unit, were enrolled and had a stool specimen collected and tested for rotavirus by enzyme immunoassay (EIA). Genotyping of positive stools was performed using reverse-transcription polymerase chain reaction and genotyping assays. Pre-vaccine introduction, 10% of all positive stool specimens were genotyped and all adequate positive stools were genotyped post-vaccine introduction. RESULTS: During the pre-vaccine period, a total of 6491 acute gastroenteritis stools were collected, of which 3016 (46%) tested positive for rotavirus and 312 (10%) of the rotavirus positive stools were genotyped. During the post-vaccine period, a total of 3750 acute gastroenteritis stools were collected, of which 937 (25%) tested positive for rotavirus and 784 (84%) were genotyped. During the pre-vaccine introduction the most frequent genotype was G9P[8] (21%) followed by G2P[4] (12%), G1P[8] (6%), G2P[6] (5%), G12P[6] (4%), G9P[6] (3%) and G8P[4] (3%). G1P[8] (30%) was most dominant two years after vaccine introduction followed by G9P[6] (20%), G2P[4] (15%), G9P[8] (11%) and G1P[6] (4%). CONCLUSION: The decline in positivity rate is an indication of early vaccine impact. Diversity of circulating strains underscores the importance of continued monitoring and strain surveillance after vaccine introduction.

Evaluation of Intussusception after Monovalent Rotavirus Vaccination in Africa.

BACKGROUND: Postlicensure evaluations have identified an association between rotavirus vaccination and intussusception in several high- and middle-income countries. We assessed the association between monovalent human rotavirus vaccine and intussusception in lower-income sub-Saharan African countries. METHODS: Using active surveillance, we enrolled patients from seven countries (Ethiopia, Ghana, Kenya, Malawi, Tanzania, Zambia, and Zimbabwe) who had intussusception that met international (Brighton Collaboration level 1) criteria. Rotavirus vaccination status was confirmed by review of the vaccine card or clinic records. The risk of intussusception within 1 to 7 days and 8 to 21 days after vaccination among infants 28 to 245 days of age was assessed by means of the self-controlled case-series method. RESULTS: Data on 717 infants who had intussusception and confirmed vaccination status were analyzed. One case occurred in the 1 to 7 days after dose 1, and 6 cases occurred in the 8 to 21 days after dose 1. Five cases and 16 cases occurred in the 1 to 7 days and 8 to 21 days, respectively, after dose 2. The risk of intussusception in the 1 to 7 days after dose 1 was not higher than the background risk of intussusception (relative incidence [i.e., the incidence during the risk window vs. all other times], 0.25; 95% confidence interval [CI], <0.001 to 1.16); findings were similar for the 1 to 7 days after dose 2 (relative incidence, 0.76; 95% CI, 0.16 to 1.87). In addition, the risk of intussusception in the 8 to 21 days or 1 to 21 days after either dose was not found to be higher than the background risk. CONCLUSIONS: The risk of intussusception after administration of monovalent human rotavirus vaccine was not higher than the background risk of intussusception in seven lower-income sub-Saharan African countries. (Funded by the GAVI Alliance through the CDC Foundation.).

Recurrent intussusception among infants less than 2 years of age in Vietnam.

In some settings, rotavirus vaccines have been associated with a low-level risk of intussusception, the most common cause of bowel obstruction in infants. As Vietnam prepares to introduce rotavirus vaccine into the national immunization program, we sought to better characterize the epidemiology of recurrent intussusception. We enrolled children <2 years of age who were hospitalized for intussusception retrospectively from January 2013 through December 2014 and prospectively from January 2015 through December 2016 at 2 hospitals in Vietnam. We enrolled 2477 children. Nearly all children were successfully treated by enema with low surgery rate (1%). We found 10% of children (n = 254) experienced at least once recurrence (range: 1-6) and 57% of first recurrences happened within the first 12 weeks after treatment of the first episode. The median age at first intussusception was 13 months for children without a recurrent episode and 10 months for children with a recurrence. The symptoms of the recurrent cases were milder with less vomiting (67%), bloody stool (7%) and fever (10%) compared to the initial cases (p < 0.01). We found the rate of recurrences following enema reduction of intussusception to be similar to that reported from other countries. Due to the high rate of intussusception and recurrent episodes in Vietnam, a better understanding of the cause of recurrent intussusception will be critical in assessing intussusception cases after rotavirus introduction.

Incidence and epidemiology of intussusception among children under 2 years of age in Chenzhou and Kaifeng, China, 2009-2013.

INTRODUCTION: In China, rotavirus is the leading cause of diarrhea hospitalizations among children aged <5 years. A locally manufactured rotavirus vaccine is available for private market use, but little is known about its coverage. Given the impending availability of newer rotavirus vaccines, we evaluated intussusception rates among children aged <2 years to better understand intussusception epidemiology for future vaccine safety monitoring. METHODS: We conducted a retrospective review at 4 hospitals in Chenzhou City of Hunan Province and Kaifeng City of Henan Province. We identified intussusception cases admitted during 2009-2013 by reviewing medical records with the ICD-10 discharge code for intussusception and extracting demographic and clinical information from the electronic clinical record systems. RESULTS: During 2009-2013, 1715 intussusception hospitalizations among 1,487,215 children aged <2 years occurred in both cities. The average annual intussusception hospitalization incidence was 112.9 per 100,000 children aged <2 years (181.8 per 100,000 children <1 year; 56 per 100,000 children 1 to <2 years). Intussusception incidence was low among infants aged <3 months and peaked at age 6-8 months. No clear seasonality was observed. Ultrasound was used to diagnose 95.9% of cases. Enema reduction was performed in 80% cases; 25% of cases in Chenzhou and 16% in Kaifeng required surgical intervention. No deaths were reported. The median time between symptom onset and admission was 1 day. CONCLUSIONS: This study provides information on intussusception incidence and epidemiology in two cities of China during 2009-2013. Monitoring intussusception rates in this population will be important in the post-rotavirus vaccine era.

Preparing for rotavirus vaccine introduction - A retrospective assessment of the epidemiology of intussusception in children below 2 years of age in Nepal.

BACKGROUND: Rotavirus is the most common cause of severe diarrhea in Nepali children, accounting for 25-33% of childhood diarrhea hospitalizations. Two rotavirus vaccines recommended for inclusion in national immunization programs have been associated with a low risk of intussusception in post-marketing studies conducted in several countries. Data on the epidemiology of intussusception hospitalizations are lacking in Nepal. Thus, we aimed to describe the epidemiology of intussusception-associated hospitalizations among Nepali children in preparation for rotavirus vaccine introduction. METHODS: A retrospective review of intussusception hospitalizations for a three year period was conducted at two major pediatric hospitals in Kathmandu, Nepal. Possible intussusception cases were identified through admission, discharge, and operation theater logs and ultrasound registers. Cases with a diagnosis of possible intussusception were selected for medical record review and classified as confirmed if they met the Brighton Collaboration level 1 criteria of diagnostic certainty and the child was aged < 24 months. Data on demographics, clinical course, and outcome were abstracted and analyzed. RESULTS: Eight-five confirmed intussusception cases were identified; most (96%) were confirmed at surgery. The number of intussusception cases peaked between ages 4-7 months; no cases occurred in children 0-2 months. Fifty-nine (64%) case-patients were male. The median duration of symptoms before admission was 2 days (range: 0-14). Abdominal pain, bloody stool, and vomiting were the most common clinical features. All cases underwent surgical treatment; there was only one death. CONCLUSIONS: This is the first study to evaluate the epidemiology of intussusception hospitalizations among children aged < 24 months in Nepal. Because the public health impact of rotavirus vaccination could be substantial in Nepal, where childhood diarrhea-related morbidity and mortality are high, this baseline knowledge of intussusception prior to introduction of rotavirus vaccine in the national immunization schedule will provide useful information for post-vaccine introduction safety monitoring.

Epidemiology of childhood intussusception in Bangladesh: Findings from an active national hospital based surveillance system, 2012-2016.

INTRODUCTION: Rotavirus vaccines have significantly decreased the burden of diarrheal diseases in countries that have introduced them into their immunization programs. In some studies, there has been a small association between rotavirus vaccines and intussusception in post-marketing surveillance, highlighting the importance of tracking incidence before and after vaccine introduction. The objective of this study was to describe the epidemiology of intussusception among Bangladeshi children pre-vaccine introduction. METHODS: We conducted active, hospital-based surveillance for intussusception at 7 tertiary care hospitals with pediatric surgical facilities during July 2012 to September 2016. Hospitalized children under 2years of age were identified according to Brighton Collaboration level 1 criteria for intussusception. The frequency and proportion of intussusception among overall surgical admissions, as well as the demographic and clinical information of the cases is described. RESULTS: Overall 153 cases of intussusception among children <2years-old were identified at participating sites over the enrolment period, confirmed by Level 1 Brighton criteria. These cases represented 2% of all surgical admissions under 2years of age. One hundred twelve cases (73%) were male; the median age was 7months; and the median duration of hospitalization was 7days. One hundred forty-six (95%) children with intussusception required surgery, and 11 (7%) died. CONCLUSIONS: Confirmed cases of intussusception represented nearly 2% of pediatric surgical admissions at tertiary referral centers in Bangladesh during the study period and 7% of children with intussusception died. Given the high burden of rotavirus disease in Bangladesh, vaccine introduction is warranted, however, further studies after introduction of rotavirus vaccine are necessary to determine any association between vaccine and intussusception in this setting.