Rotavirus vaccination effectiveness: A case–case study in the EDICS project, Castellón (Spain)

Сost-effectiveness of pentavalent rotavirus vaccination in the Russian Federation

   One of the main causes of acute gastroenteritis in children under 5 years of age is rotavirus infection (RVI). Vaccines against RVI significantly reduce the incidence.   Aim. To evaluate the cost-effectiveness of mass vaccination of children with a 5-valent RVI vaccine in the Russian Federation.   Materials and methods. The assessment was carried out using modeling based on published data on the effectiveness of the vaccine and epidemiological indicators in the Russian Federation. The analysis was carried out from the perspective of the health care system and society as a whole with a 5-year horizon. The cost of RVI therapy corresponded to the compulsory health insurance tariffs for St. Petersburg for 2022, the price of 1 dose of the vaccine was the registered price, including VAT. Costs and life expectancy, taking into account quality, were discounted at 3.5 % per year.   Results. Given the assumptions made, routine vaccination will prevent an average of 468,637 cases of RVI over 5 years. Avoided direct medical costs, i. e. RVI treatment costs will amount to 53,4 %, and lost income due to temporary disability – 46,6 % of the total avoided costs. At the same time, the volume of avoided costs is 61,4 % due to a decrease in morbidity in the vaccinated population, and 38.6 % due to the development of a indirect effect. The predicted avoided costs per 1 vaccinated person is 2,975 thousand rubles. From a societal perspective, the cost-effectiveness of the Rota-V-Aid vaccine will be 364,813 thousand rubles / QALY (quality-adjusted life year), and from a healthcare perspective – 1726,399 thousand rubles / QALY. Thus, in both cases, the cost-effectiveness of RVI vaccination will not exceed the generally accepted threshold of willingness to pay, equal to three times the gross domestic product per capita in the Russian Federation (according to data for 2021 – ~2,7 million rubles). The predicted cost-effectiveness of selective vaccination is significantly lower than that of mass vaccination.   Conclusions. Mass vaccination of children with a 5-valent vaccine against RVI will not only reduce the incidence in the Russian Federation, but, taking into account the assumptions made, can also be considered as a cost-effective intervention.

Prevalence of Rotaviruses in the Etiology of Acute Diarrhea in Young Children, Clinical forms, Extraintestinal Manifestations and Complications

Rotavirus is highly contagious factor with dominant feces-oral transmission. Because it is stable in external environment, transmission clusters are possible by close contact, ingestion of contaminated water or food or contact with contaminated surfaces. It survives within hours and days on hands and contaminated surfaces. This makes it the most common enteric and nosocomial pathogen in the world, especially in early childhood. In addition to the rapid dehydration with pronounced electrolyte disturbances, numerous extraintestinal possibilities have been recorded in the clinical picture, which emphasizes the need for prevention of this disease.In the period from 1.02.2018 to 31.01.2020 at the Clinic for Infectious diseases were treated 1060 patients with diarrheal disease, of which 502 children (47.36%). Rotavirus etiology was confirmed in 23.30% of the children. According to the protocols, laboratory and biochemical investigations were done to all 117 children, with tracking parameters and their dynamics of admission and discharge from the hospital. Most of the children, 84 (82.0 6%) are from urban areas, with a more confirmed epidemiological survey of 59 (42.00%). The average age of the children was 8 months, with a small percentage of children on maternal food (breastfed 25, i.e. 21.37%), with high febrile admission in 99% of children with an average temperature of 38.5oC and an average febrile duration of 4 days, with an average of 7 (+ 2.49) of stools and 5 (+ 2.12) of vomiting. There was a significant difference in hematocrit, leukocyte, electrolyte, glycaemia, and CRP values on admission and discharge. There was predominant isonatremic dehydration, and the compensatory mechanisms followed by the values of the electrolytes ABS, Ph, BE showed a tendency to maintain within the physiological limits. The clinical picture of extraintestinal manifestations included bronchitis, mesenteric lymphadenitis, upper respiratory infections and rash.Rotavirus infection is a serious health and economic problem in our country, so it needs continuous prevention and monitoring in order to reduce the incidence, and thus the need for hospitalization and cure of rotavirus disease.

The Use of Test-negative Controls to Monitor Vaccine Effectiveness: A Systematic Review of Methodology

BACKGROUND

The test-negative design is an increasingly popular approach for estimating vaccine effectiveness (VE) due to its efficiency. This review aims to examine published test-negative design studies of VE and to explore similarities and differences in methodological choices for different diseases and vaccines.

METHODS

We conducted a systematic search on PubMed, Web of Science, and Medline, for studies reporting the effectiveness of any vaccines using a test-negative design. We screened titles and abstracts and reviewed full texts to identify relevant articles. We created a standardized form for each included article to extract information on the pathogen of interest, vaccine(s) being evaluated, study setting, clinical case definition, choices of cases and controls, and statistical approaches used to estimate VE.

RESULTS

We identified a total of 348 articles, including studies on VE against influenza virus (n = 253), rotavirus (n = 48), pneumococcus (n = 24), and nine other pathogens. Clinical case definitions used to enroll patients were similar by pathogens of interest but the sets of symptoms that defined them varied substantially. Controls could be those testing negative for the pathogen of interest, those testing positive for nonvaccine type of the pathogen of interest, or a subset of those testing positive for alternative pathogens. Most studies controlled for age, calendar time, and comorbidities.

CONCLUSIONS

Our review highlights similarities and differences in the application of the test-negative design that deserve further examination. If vaccination reduces disease severity in breakthrough infections, particular care must be taken in interpreting vaccine effectiveness estimates from test-negative design studies.

Identification of Conserved Candidate Vaccine Antigens in the Surface Proteome of Giardia lamblia

Giardia lamblia, one of the most common protozoal infections of the human intestine, is an important worldwide cause of diarrheal disease, malabsorption, malnutrition, delayed cognitive development in children, and protracted postinfectious syndromes. Despite its medical importance, no human vaccine is available against giardiasis. A crude veterinary vaccine has been developed, and experimental vaccines based on expression of multiple variant-specific surface proteins have been reported, but poorly defined vaccine components and excessive antigen variability are problematic for pharmaceutical vaccine production. To expand the repertoire of antigen candidates for vaccines, we reasoned that surface proteins may provide an enriched source of such antigens since key host effectors, such as secretory IgA, can directly bind to such antigens in the intestinal lumen and interfere with epithelial attachment. Here, we have applied a proteomics approach to identify 23 novel surface antigens of G. lamblia that show >90% amino acid sequence identity between the two human-pathogenic genetic assemblages (A and B) of the parasite. Surface localization of a representative subset of these proteins was confirmed by immunostaining. Four selected proteins, uridine phosphorylase-like protein-1, protein 21.1 (GL50803_27925), α1-giardin, and α11-giardin, were subsequently produced in recombinant form and shown to be immunogenic in mice and G. lamblia-infected humans and confer protection against G. lamblia infection upon intranasal immunization in rodent models of giardiasis. These results demonstrate that identification of conserved surface antigens provides a powerful approach for overcoming a key rate-limiting step in the design and construction of an effective vaccine against giardiasis.

[What have we learnt about rotavirus in Spain in the last 10 years?]

INTRODUCTION

Vaccines against rotavirus (RV) have been available in Spain since 2006, but they are neither recommended nor financed by the National Health System. Nevertheless, through recommendations of the Spanish Association of Paediatrics vaccination has achieved intermediate coverage.

MATERIAL AND METHODS

A systematic literature review was performed on studies carried out in Spain in the last 12 years (2006-2018) on RV infection and vaccination.

RESULTS

A total of 43 studies were identified that met the inclusion criteria. The disease burden in children less than 5 years in the Primary Care setting ranged from 15 to 19 cases per 1,000 children, and between 120 and 480 cases per 100,000 in the hospital setting, which has a significant economic and social impact. Vaccines against RV have shown an effectiveness of between 83% and 96%, and an impact of up to 70% in reducing hospital admissions, which is dependent on the achieved vaccine coverage. New research lines are identified, such as the role of the rotavirus vaccine and protection against seizures or the impact on the gut microbiota.

CONCLUSIONS

The current available information supports the significant burden of rotavirus disease in Spain and the high effectiveness of the available vaccines. This evidence should allow for an updated re-evaluation of the national recommendations on rotavirus vaccination.

Descriptive epidemiology of Yersinia enterocolitica infection in a high-incidence area over an 8-year period, 2006-2013. EDICS project

Descriptive epidemiology of Yersinia enterocolitica infection in an area of Castellón (Spain) between 2006 and 2013 from Yersinia enterocolitica strains isolated in the area and confirmed by the Spanish national reference laboratory. There were a total of 144 cases. The estimated incidence was 9.7 cases per 10⁵ person-year. The age group most affected was 0-4 years (rate 110.3 per 10⁵ p-y), with a maximum in infants aged 6 to 11 months of age (190.4 per 10⁵ p-y). The average duration of the disease was 15.5 days. 7% of the patients were hospitalised. Only 2 outbreaks of a family nature related to the consumption of pork were detected. The temporal evolution reflects higher incidence during the winter season (January). The most common exposure factor among the cases was the consumption of dried pork sausage (50% of the cases interviewed). The 58 typed strains were all of the biotype 4, serotype O:3, except one O:9. We distinguished 21 pulsotypes grouped in 8 clusters with a similarity of 97%. Over a number of years, a substitution of some pulsotypes for others was observed. Yersiniosis has a high incidence in our area, with a clear seasonality of winter predominance. It affects very young children, in particular. The strains are of the same serotype, but the variety of pulsotypes changed over time. As an exposure factor for further analytical studies, the consumption of some pork products is proposed, without ruling out other factors.

Case-Control Study of Rotavirus Vaccine Effectiveness Compared to Test-Negative Controls or Hospital Controls

Background

Selection of test-negative controls takes less time and costs less than traditional control selection for evaluating vaccine effectiveness (VE). Here, rotavirus VE was evaluated using hospital controls and compared with test-negative controls to determine whether using the latter can substitute for the former.

Methods

We recorded gastroenteritis in children from 2 months to 2 years of age at six medical facilities in Saga City between January 4th and May 31st, 2014. Stools from all identified acute gastroenteritis patients were tested for rotavirus using immunochromatography. Rotavirus gastroenteritis (RVGE) cases had test-positive stool, whereas test-negative controls had gastroenteritis but no rotavirus infection; hospital controls were outpatients visiting the same facility for indications other than gastroenteritis. Vaccination status was verified by inspecting maternal and child health records, and demographic data were obtained from a questionnaire completed by the patients’ guardians or from the medical records. Unconditional logistic regression analysis was used to adjust for possible confounding factors.

Results

Sixty-four RVGE cases, 260 test-negative controls, and 589 hospital controls were enrolled. The characteristics of the two control groups, including RV vaccination history, were similar. The RVGE cases were more likely to have used daycare services than children from either of the two control groups. The VE against RVGE estimated using hospital controls was 86.6% (95% confidence interval [CI], 55.9–96.0%), very similar to the VE using test-negative controls (84.9% [95% CI, 49.6–95.5%]).

Conclusions

The estimated VE using test-negative controls and hospital controls is similar. Therefore, test-negative controls are considered appropriate for establishing VE.

Population effectiveness of the pentavalent and monovalent rotavirus vaccines: a systematic review and meta-analysis of observational studies

BACKGROUND

Rotavirus was the leading cause of acute gastroenteritis (AGE) in infants and young children prior to the introduction of routine vaccination. Since 2006 there have been two licensed vaccines available; with successful clinical trials leading the World Health Organization to recommend rotavirus vaccination for all children worldwide. In order to inform immunisation policy we have conducted a systematic review and meta-analysis of observation studies to assess population effectiveness against acute gastroenteritis.

METHODS

We systematically searched PubMed, Medline, Web of Science, Cinhal and Academic Search Premier and grey literature sources for studies published between January 2006 and April 2014. Studies were eligible for inclusion if they were observational measuring population effectiveness of rotavirus vaccination against health care attendances for rotavirus gastroenteritis or AGE. To evaluate study quality we use used the Newcastle-Ottawa Scale for non-randomised studies, categorising studies by risk of bias. Publication bias was assessed using funnel plots. If two or more studies reported a measure of vaccine effectiveness (VE), we conducted a random effects meta-analysis. We stratified analyses by World Bank country income level and used study quality in sensitivity analyses.

RESULTS

We identified 30 studies, 19 were from high-income countries and 11 from middle-income countries. Vaccine effectiveness against hospitalization for laboratory confirmed rotavirus gastroenteritis was highest in high-income countries (89% VE; 95% CI 84-92%) compared to middle-income countries (74% VE; 95% CI 67-80%). Vaccine effectiveness was higher for those receiving the complete vaccine schedule (81% VE; 95% CI 75-86%) compared to partial schedule (62% VE; 95% CI 55-69%). Two studies from high-income countries measured VE against community consultations for AGE with a pooled estimate of 40% (95% CI 13-58%; 2 studies).

CONCLUSIONS

We found strong evidence to further support the continued use of rotavirus vaccines. Vaccine effectiveness was similar to that reported in clinical trials for both high and middle-income countries. There is limited data from Low income settings at present. There was lower effectiveness against milder disease. Further studies, should continue to report effectiveness against AGE and less-severe rotavirus disease because as evidenced by pre-vaccine introduction studies this is likely to contribute the greatest burden on healthcare resources, particularly in high-income countries.

The effectiveness of rotavirus vaccine in preventing acute gastroenteritis during rotavirus seasons among Polish children

INTRODUCTION

Rotavirus is the main etiological cause of intestinal infections in children. Voluntary rotavirus vaccines were included in the Polish vaccination schedule in 2007. The aim of this study was to assess the effectiveness of a completed rotavirus vaccination course in preventing acute gastroenteritis in Polish infants during their first five years of life.

MATERIAL AND METHODS

This was a retrospective cohort study conducted in Lesser Poland (Malopolska Province). The sample population included a group of 303 children who received the completed rotavirus vaccination course and 303 children not vaccinated against rotavirus. The date of the child's acute gastroenteritis diagnosis and his or her vaccination history were extracted from the physicians' records. Each kind of diagnosed acute gastroenteritis during winter-spring rotavirus seasons was treated as the endpoint. The relative risk of having gastrointestinal infection was assessed using the hazard ratio from the Cox proportional hazards regression model.

RESULTS

In the examined group, 96 (15.8%) children had winter-spring gastrointestinal infections. In the non-vaccinated children, the cumulative incidence of these infections in the first 5 years of life was 20.8%, whereas in the children vaccinated with Rotarix it was only 10.9%. Those who were vaccinated with Rotarix had a 44% reduction in the risk of a winter-spring acute gastroenteritis infection compared to those not vaccinated with Rotarix (p = 0.005). Birth weight less than 2500 g increased the risk of the infection twofold and also reached statistical significance (p = 0.044).

CONCLUSIONS

The results showed that Rotarix is effective in preventing acute gastroenteritis in Polish children during rotavirus seasons.

Estimating rotavirus vaccine effectiveness in Japan using a screening method

Rotavirus gastroenteritis is a highly contagious, acute viral disease that imposes a significant health burden worldwide. In Japan, rotavirus vaccines have been commercially available since 2011 for voluntary vaccination, but vaccine coverage and effectiveness have not been evaluated. In the absence of a vaccination registry in Japan, vaccination coverage in the general population was estimated according to the number of vaccines supplied by the manufacturer, the number of children who received financial support for vaccination, and the size of the target population. Patients with rotavirus gastroenteritis were identified by reviewing the medical records of all children who consulted 6 major hospitals in Saga Prefecture with gastroenteritis symptoms. Vaccination status among these patients was investigated by reviewing their medical records or interviewing their guardians by telephone. Vaccine effectiveness was determined using a screening method. Vaccination coverage increased with time, and it was 2-times higher in municipalities where the vaccination fee was supported. In the 2012/13 season, vaccination coverage in Saga Prefecture was 14.9% whereas the proportion of patients vaccinated was 5.1% among those with clinically diagnosed rotavirus gastroenteritis and 1.9% among those hospitalized for rotavirus gastroenteritis. Thus, vaccine effectiveness was estimated as 69.5% and 88.8%, respectively. This is the first study to evaluate rotavirus vaccination coverage and effectiveness in Japan since vaccination began.

Case control study of rotavirus vaccine effectiveness in Portugal during 6 years of private market use

BACKGROUND

Although recommended by the vaccine committee of the Portuguese Paediatric Society, rotavirus vaccines have not been included in the routine immunization schedule. They have been available privately since 2006 with estimated coverage reaching approximately 30%. However, unlike other European countries using the vaccine, sentinel surveillance has detected fluctuations but no clear trends in the rate of gastrointestinal disease presentations. In this study, we set out to establish the real world effectiveness of rotavirus immunization in this low vaccine coverage setting.

METHODS

We carried out a test-negative case control study on a population of children attending a regional pediatric hospital, between 2006 and 2012, with symptoms of acute gastroenteritis and producing a stool sample for routine rotavirus testing. We calculated exposure odds ratio (ratio of odds of antecedent vaccination among cases compared with controls) to derive vaccine effectiveness ([1 - adjusted odds ratio]/100) against both hospital attendance and admission.

RESULTS

Vaccine effectiveness against attendance with rotavirus acute gastroenteritis was 83.7% (95% confidence interval: 73.9-89.8) and against hospital admission was 96.1% (95% confidence interval: 83.8-99.1). No significant difference between the 2 available vaccines was detected.

CONCLUSION

Both rotavirus vaccines offer a high degree of individual protection in this population.

Effectiveness of rotavirus vaccines, licensed but not funded, against rotavirus hospitalizations in the Valencia Region, Spain

BACKGROUND

Although rotavirus vaccines have been licensed in Spain for over 8 years, they are not funded by its public health systems. The analysis of their effectiveness in the Valencia Region could better inform decisions about potential inclusion in the official immunization schedule. Our aim was to assess the effectiveness of Rotarix® (RV1) and RotaTeq® (RV5) against rotavirus hospitalizations.

METHODS

We conducted a retrospective cohort study using the region's health care databases, among resident children aged <3 years covered by the National Health System, during January 2007-June 2012. We compared two cohorts of vaccinated children: the first included children who received at least one dose of a rotavirus vaccine, and the second included children who were not vaccinated with rotavirus vaccines but received at least one dose of a pneumococcal vaccine, another licensed but non-funded vaccine. The main outcome was rotavirus hospitalization, either laboratory-confirmed (confirmed) or codified as rotavirus (probable). Rotavirus vaccine effectiveness (RVE) by vaccine brand was assessed using Cox proportional hazards models.

RESULTS

The study included 78,281 rotavirus and 96,643 pneumococcal vaccinees. Adjusted RVE against probable or confirmed rotavirus hospitalizations was 86% (95% CI: 78-91%) and 88% (95% CI: 81-92%) for a complete series of RV1 and RV5 respectively.

CONCLUSIONS

Both rotavirus vaccines were over 85% effective against rotavirus hospitalization among young children. The high effectiveness shown argues in favor of their inclusion in the official schedule. Additional information on rotavirus vaccine safety, duration of protection, and benefit-risk will also be needed to inform such deliberations.