Assessment of the Impact of the Rotavirus Vaccine Against Severe Rotaviral Diarrhea in Uzbekistan.

BACKGROUND: This article presents the results of a long-term study of the impact of rotavirus vaccination in Uzbekistan. Uzbekistan is the first country in the Central Asian region to introduce rotavirus vaccination into the national compulsory vaccination calendar. The study aimed to evaluate the impact of rotavirus vaccination on hospitalizations due to all-cause AGE and RVGE in children < 5 years of age in Uzbekistan. METHODS: Detection of rotavirus antigen was performed using Rotavirus-Antigen-IFA-BEST "Vector Best" kit (Novosibirsk, Russia). RESULTS: The total of 20,128 children under 5 years of age were hospitalized in sentinel hospitals with a diagnosis of acute gastroenteritis during the study period (2019-2020). Of this number of children, 4481 children (22.2%) were included in the study. Of 4481 children, 367 (8.2%) children tested positive for rotavirus. In our study, decrease in the rotavirus rate was noted in all age groups. The peak of rotavirus positivity occurred in the months of January and February. CONCLUSION: The average rotavirus-positive rate in the period (2019-2020) was 8.2% and the absolute percentage decrease was 18.1% compared to the pre-vaccination period (2005-2009) where the rotavirus-positive rate was 26.3%. The percentage of prevented cases averaged 68.8%.

Efficacy, safety and immunogenicity of hexavalent rotavirus vaccine in Chinese infants.

A randomized, double-blind, placebo-controlled multicenter trial was conducted in healthy Chinese infants to assess the efficacy and safety of a hexavalent live human-bovine reassortant rotavirus vaccine (HRV) against rotavirus gastroenteritis (RVGE). A total of 6400 participants aged 6-12 weeks were enrolled and randomly assigned to either HRV (n â€‹= â€‹3200) or placebo (n â€‹= â€‹3200) group. All the subjects received three oral doses of vaccine four weeks apart. The vaccine efficacy (VE) against RVGE caused by rotavirus serotypes contained in HRV was evaluated from 14 days after three doses of administration up until the end of the second rotavirus season. VE against severe RVGE, VE against RVGE hospitalization caused by serotypes contained in HRV, and VE against RVGE, severe RVGE, and RVGE hospitalization caused by natural infection of any serotype of rotavirus were also investigated. All adverse events (AEs) were collected for 30 days after each dose. Serious AEs (SAEs) and intussusception cases were collected during the entire study. Our data showed that VE against RVGE caused by serotypes contained in HRV was 69.21% (95%CI: 53.31-79.69). VE against severe RVGE and RVGE hospitalization caused by serotypes contained in HRV were 91.36% (95%CI: 78.45-96.53) and 89.21% (95%CI: 64.51-96.72) respectively. VE against RVGE, severe RVGE, and RVGE hospitalization caused by natural infection of any serotype of rotavirus were 62.88% (95%CI: 49.11-72.92), 85.51% (95%CI: 72.74-92.30) and 83.68% (95%CI: 61.34-93.11). Incidences of AEs from the first dose to one month post the third dose in HRV and placebo groups were comparable. There was no significant difference in incidences of SAEs in HRV and placebo groups. This study shows that this hexavalent reassortant rotavirus vaccine is an effective, well-tolerated, and safe vaccine for Chinese infants.

Gastroenteritis attributable to rotavirus in hospitalized Saudi Arabian children in the period 2007-2008.

PURPOSE: Rotavirus (RV) is a leading cause of severe gastroenteritis (GE) in children across the world. As there is a lack of epidemiological data for RV gastroenteritis (RVGE) in Saudi Arabia, this hospital-based study was designed to estimate the disease burden of RVGE and assess the prevalent RV types in Saudi children younger than 5 years of age. PATIENTS AND METHODS: Children hospitalized for acute GE were enrolled at four pediatric referral hospitals in Saudi Arabia. The study was conducted from February 2007 to March 2008 and used the World Health Organization's generic protocol for RVGE surveillance. The Vesikari severity scale was used to assess the severity of RVGE. Stool samples were tested for RV using an enzyme-linked immunosorbent assay. Samples were further typed by reverse transcriptase-polymerase chain reaction and hybridization assay for determining the G and P types. RESULTS: A total of 1,007 children were enrolled; the final analysis included 970 children, of whom 395 were RV positive, 568 were RV negative, and seven had unknown RV status. The proportion of RVGE among GE hospitalizations was 40.7% (95% confidence interval: 37.6-43.9). The highest percentage of RVGE hospitalizations (83.1%) was seen in children younger than 2 years of age. The highest proportion of RV among GE hospitalizations was in June 2007 with 57.1%. The most common RV types detected were G1P[8] (49.3%), G1G9P[8] (13.2%), and G9P[8] (9.6%). Before hospitalization, severe GE episodes occurred in 88.1% RV-positive and 79.6% RV-negative children. Overall, 94% children had recovered by the time they were discharged. Two children (one RV positive and one RV negative) died due to GE complications. CONCLUSION: RVGE is responsible for a high proportion of hospitalizations in Saudi children younger than 5 years of age. Routine RV vaccination has therefore been introduced into the national immunization program and may help reduce the morbidity, mortality, and disease burden associated with RVGE in Saudi Arabia.

Cost-effectiveness of a new rotavirus vaccination program in Pakistan: a decision tree model.

BACKGROUND: Rotavirus gastroenteritis places a significant health and economic burden on Pakistan. To determine the public health impact of a national rotavirus vaccination program, we performed a cost-effectiveness study from the perspective of the health care system. METHODS: A decision tree model was developed to assess the cost-effectiveness of a national vaccination program in Pakistan. Disease and cost burden with the program were compared to the current state. Disease parameters, vaccine-related costs, and medical treatment costs were based on published epidemiological and economic data, which were specific to Pakistan when possible. An annual birth cohort of children was followed for 5 years to model the public health impact of vaccination on health-related events and costs. The cost-effectiveness was assessed and quantified in cost (2012 US$) per disability-adjusted life-year (DALY) averted and cost per death averted. Sensitivity analyses were performed to assess the robustness of the incremental cost-effectiveness ratios (ICERs). RESULTS: The base case results showed vaccination prevented 1.2 million cases of rotavirus gastroenteritis, 93,000 outpatient visits, 43,000 hospitalizations, and 6700 deaths by 5 years of age for an annual birth cohort scaled from 6% current coverage to DPT3 levels (85%). The medical cost savings would be US$1.4 million from hospitalizations and US$200,000 from outpatient visit costs. The vaccination program would cost US$35 million at a vaccine price of US$5.00. The ICER was US$149.50 per DALY averted or US$4972 per death averted. Sensitivity analyses showed changes in case-fatality ratio, vaccine efficacy, and vaccine cost exerted the greatest influence on the ICER. CONCLUSIONS: Across a range of sensitivity analyses, a national rotavirus vaccination program was predicted to decrease health and economic burden due to rotavirus gastroenteritis in Pakistan by ~40%. Vaccination was highly cost-effective in this context. As discussions of implementing the intervention intensify, future studies should address affordability, efficiency, and equity of vaccination introduction.

Efficacy and safety of pentavalent rotavirus vaccine in Japan: a randomized, double-blind, placebo-controlled, multicenter trial.

Rotavirus is the most common cause of severe gastroenteritis in children under 5 y of age. Estimates of disease burden in Japan suggest that between 26,500 and 78,000 children in this age group need hospitalization each year, resulting in a direct medical cost of 10 to 24 billion Yen. Since being introduced in routine infant immunization schedules in the United States in 2006, the oral live pentavalent rotavirus vaccine RV5 (RotaTeq™) has contributed to dramatic reductions in the incidence of rotavirus gastroenteritis (RVGE) and in health care resource utilization. This was a multicenter, randomized, double-blind, placebo-controlled, parallel-group study to evaluate the efficacy and safety of a 3-dose regimen of RV5 in healthy infants, age 6 to 12 weeks, at 32 sites across Japan. The results indicate that RV5 was significantly efficacious in preventing any severity [74.5% (95% confidence interval [CI]: 39.9%, 90.6%; p<0.001)], moderate-to-severe [80.2% (95% CI: 47.4%, 94.1%)], and severe [100% (95% CI: 55.4%, 100%)] RVGE caused by viruses with serotypes contained in the vaccine. The observed cases of RVGE included rotavirus types G1 (n=19), G3 (n=9), G9 (n=5) and one unspecified G serotype with P1A[8]. No G2 or G4 RVGE cases were observed, and this study was not powered to evaluate efficacy against individual serotypes. RV5 was generally safe and well tolerated in Japanese infants. These results are comparable to those observed in clinical studies conducted in other developed countries. Introduction of the vaccine in Japan may reduce disease burden and associated health care costs.