Accuracy of administrative claims data to identify dose specific rotavirus vaccination information: Implications for studies of vaccine safety

BackgroundThe accuracy of vaccine administration information recorded in administrative claims databases is uncertain.MethodsWe conducted a retrospective cohort study using the HealthCore Integrated Research Database^SM among infants who received at least 1 RotaTeq^® (RV5) dose during the first year of life between February 1, 2006 and November 30, 2012 and were enrolled in the health plan at birth. We reviewed medical records for a sample of infants to validate vaccine administration information.ResultsWe identified 169,560 infants who received at least 1 RV5 dose. Medical records were obtained for 85 infants, of which 74 (PPV1 87.1%; 95% CI 78.0–93.4%) had a corresponding first RV5 vaccination in the medical record with the same or similar administration date.ConclusionsAdministrative claims contained inaccuracies in dose number or administration date for 13% of RV5 first doses identified.     

Targeting of rotavirus VP6 to DEC-205 induces protection against the infection in mice

Rotavirus (RV) is the primary etiologic agent of severe gastroenteritis in human infants. Although two attenuated RV-based vaccines have been licensed to be applied worldwide, they are not so effective in low-income countries, and the induced protection mechanisms have not been clearly established. Thus, it is important to develop new generation vaccines that induce long lasting heterotypic immunity. VP6 constitutes the middle layer protein of the RV virion. It is the most conserved protein and it is the target of protective T-cells; therefore, it is a potential candidate antigen for a new generation vaccine against the RV infection. We determined whether targeting the DEC-205 present in dendritic cells (DCs) with RV VP6 could induce protection at the intestinal level. VP6 was cross-linked to a monoclonal antibody (mAb) against murine DEC-205 (αDEC-205:VP6), and BALB/c mice were inoculated subcutaneously (s.c.) twice with the conjugated containing 1.5 μg of VP6 in the presence of polyinosinic–polycytidylic acid (Poly I:C) as adjuvant. As controls and following the same protocol, mice were immunized with ovalbumin (OVA) cross-linked to the mAb anti-DEC-205 (αDEC-205:OVA), VP6 cross-linked to a control isotype mAb (Isotype:VP6), 3 μg of VP6 alone, Poly I:C or PBS. Two weeks after the last inoculation, mice were orally challenged with a murine RV. Mice immunized with α-DEC-205:VP6 and VP6 alone presented similar levels of serum Abs to VP6 previous to the virus challenge. However, after the virus challenge, only α-DEC-205:VP6 induced up to a 45% IgA-independent protection. Memory T-helper (Th) cells from the spleen and the mesenteric lymph node (MLN) showed a Th1-type response upon antigen stimulation in vitro. These results show that when VP6 is administered parenterally targeting DEC-205, it can induce protection at the intestinal level at a very low dose, and this protection may be Th1-type cell dependent.     

Rotavirus vaccination compliance and completion in a Medicaid infant population

We examined completion and compliance rates of rotavirus (RV) vaccination according to the recommendations of the Advisory Committee on Immunization Practices (ACIP) and the Food and Drug Administration approved Prescribing Information (PI) for Rotarix^® (RV1, GlaxoSmithKline Vaccines) and RotaTeq^® (RV5, Merck and Co.) among infants under one year of age covered by Medicaid programs. Healthcare claims data from state Medicaid programs that constituted the Truven Health MarketScan^® Multi-State Medicaid Database were retrieved from May 2008–June 2012. Infants were grouped under PI and ACIP cohorts based on the dosing regimens followed. The overall compliance per PI (n = 673,956) and ACIP (n = 695,612) recommendations were 24.5% and 28.2%, respectively; completion rates were 30.3% and 32.6%, respectively. In the PI cohort, infants who received RV1 had significantly higher compliance as compared with infants who received RV5 (65.2% vs. 31.3%; p < 0.0001); completion rates among infants receiving RV1 and RV5 were 65.3% and 46.4%, respectively (p < 0.0001). In the ACIP cohort, compliance with RV1 was significantly higher than RV5 (68.8% vs. 45.9%; p < 0.0001) as was the overall completion rate (73.5% vs. 48.8%; p < 0.0001). While compliance is increasing year over year, overall compliance of RV vaccines is suboptimal, with over 40% of eligible infants unvaccinated in both populations. The 2-dose RV vaccine showed better completion rates and higher compliance than the 3-dose RV vaccine in the United States. Public health initiatives focusing on suboptimal compliance and completion rates of RV vaccination in the Medicaid population could improve these metrics, thereby offering protection against RV infection.     

Estimating the herd immunity effect of rotavirus vaccine

IntroductionDiarrhea is one of the leading causes of death in children under 5, and an estimated 39% of these deaths are attributable to rotavirus. Currently two live, oral rotavirus vaccines have been introduced on the market; however, the herd immunity effect associated with rotavirus vaccine has not yet been quantified. The purpose of this meta-analysis was to estimate the herd immunity effects associated with rotavirus vaccines.MethodsWe performed a systematic literature review of articles published between 2008 and 2014 that measured the impact of rotavirus vaccine on severe gastroenteritis (GE) morbidity or mortality. We assessed the quality of published studies using a standard protocol and conducted meta-analyses to estimate the herd immunity effect in children less than one year of age across all years presented in the studies. We conducted these analyses separately for studies reporting a rotavirus-specific GE outcome and those reporting an all-cause GE outcome.ResultsIn studies reporting a rotavirus-specific GE outcome, four of five of which were conducted in the United States, the median herd effect across all study years was 22% [19–25%]. In studies reporting an all-cause GE outcome, all of which were conducted in Latin America, the median herd effect was 24.9% [11–30%].ConclusionsThere is evidence that rotavirus vaccination confers a herd immunity effect in children under one year of age in the United States and Latin American countries. Given the high variability in vaccine efficacy across regions, more studies are needed to better examine herd immunity effects in high mortality regions.     

Factors that affect voluntary vaccination of children in Japan

Some important vaccinations are not included in the routine childhood immunization schedule in Japan. Voluntary vaccinations are usually paid as an out-of-pocket expense. Low voluntary vaccination coverage rates and high target disease incidence are assumed to be a consequence of voluntary vaccination. Therefore, this study aimed to explore factors associated with voluntary vaccination patterns in children. We conducted an online survey of 1243 mothers from a registered survey panel who had at least one child 2 months to <3 years of age. The voluntary vaccination mainly correlated positively with annual household income and mothers’ positive opinions about voluntary vaccinations, but negatively with number of children. Financial support, especially for low income households and households with more than one child, may motivate parents to vaccinate their children. Communication is also an important issue. More opportunities for education and information about voluntary vaccinations should be provided to mothers without distinguishing between voluntary and routine vaccination.     

Increased detection of G3P[9] and G6P[9] rotavirus strains in hospitalized children with acute diarrhea in Bulgaria

Rotavirus severe disease in children is now vaccine-preventable and the roll-out of vaccination programs globally is expected to make a significant impact in the reduction of morbidity and mortality in children <5 years of age. Rotavirus is also a pathogen of other mammals and birds, and its segmented RNA genome can lead to the emergence of new or unusual strains in human population via interspecies transmission and reassortment events. Despite the efficacy and impact of rotavirus vaccine in preventing severe diarrhea, the correlates of protection remain largely unknown. Therefore, rotavirus strain surveillance before, during and after the introduction of immunization programs remains a crucial for monitoring rotavirus vaccine efficacy and impact. In this context, molecular characterization of 1323 Bulgarian rotavirus strains collected between June 2010 and May 2013 was performed. A total of 17 strains of interest were analyzed by partial sequence analysis. Twelve strains were characterized as G3P[9] and G6P[9] of potential animal origin. Phylogenetic analysis and comparisons with the same specificity strains detected sporadically between 2006 and 2010 revealed the constant circulation of these unusual human strains in Bulgaria, although in low prevalence, and their increased potential for person-to-person spread.     

轮状病毒肠炎肠外器官损伤的临床研究

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人轮状病毒疫苗研究进展

轮状病毒(RV)是引起婴幼儿和幼龄动物腹泻的主要病原体,轮状病毒无特效药物进行治疗,只能通过疫苗免疫预防,因此,轮状病毒疫苗的合理应用在降低全世界轮状病毒性腹泻的发病率和死亡率中显得尤为重要。但目前商品化的口服减毒活疫苗存在潜在的安全性问题以及在中低收入国家免疫效力不高的缺陷,需要研发更加安全、高效的疫苗来防控轮状病毒性腹泻。近年来,随着轮状病毒研究的不断深入,鉴定出了新的轮状病毒血清型,并且有4种轮状病毒疫苗通过世界卫生组织的使用资格预审,还有一些新型疫苗正处于研发阶段。本文根据各国学者的研究对轮状病毒疫苗研究进展做一综述,为进一步研究提供一定的参考。     

对一步夹心法轮状病毒单克隆抗体酶标试剂盒的评价

以一步夹心法轮状病毒单克隆抗体酶标试剂盒及聚丙烯酰胺凝胶电泳对253份粪样进行检测,结果显示试剂盒敏感度和特异度分别为96.36％和96.28％;阳性预示值和阴性预示值分别为98.15％和92.45％;试剂盒批内和批间变异系数分别为4.65％和8.06％。表明本试剂盒敏感性和特异性均好,且较稳定,适用于临床快速诊断。