关键词： immunization   IPV   OPV   polio   war   Nigeria  

摘要： The use of Inactivated Polio Vaccine (IPV) in routine immunization to replace Oral Polio Vaccine (OPV) is crucial in eradicating polio. In June 2014, Nigeria launched an IPV campaign in the conflict-affected states of Borno and Yobe, the largest ever implemented in Africa. We present the initiatives and lessons learned. The 8-day event involved two parallel campaigns. OPV target age was 0-59 months, while IPV targeted all children aged 14 weeks to 59 months. The Borno state primary health care agency set up temporary health camps for the exercise and treated minor ailments for all. The target population for the OPV campaign was 685 674 children in Borno and 113 774 in Yobe. The IPV target population for Borno was 608 964 and for Yobe 111 570. OPV coverage was 105.1 per cent for Borno and 103.3 per cent for Yobe. IPV coverage was 102.9 per cent for Borno and 99.1 per cent for Yobe. (Where we describe coverage as greater than 100 per cent, this reflects original underestimates of the target populations.) A successful campaign and IPV immunization is viable in conflict areas.

关键词： Rotarix   rotavirus vaccine   oral polio vaccine   OPV   vaccine interference  

摘要： Background. Trivalent oral poliovirus vaccine (OPV) is known to interfere with monovalent rotavirus vaccine (RV1) immunogenicity. The interference caused by bivalent and monovalent OPV formulations, which will be increasingly used globally in coming years, has not been examined. We conducted a post hoc analysis to assess the effect of coadministration of different OPV formulations on RV1 immunogenicity. Methods. Healthy infants in Matlab, Bangladesh, were randomized to receive 3 doses of monovalent OPV type 1 or bivalent OPV types 1 and 3 at either 6, 8, and 10 or 6, 10, and 14 weeks of age or trivalent OPV at 6, 10, and 14 weeks of age. All infants received 2 doses of RV1 at about 6 and 10 weeks of age. Concomitant administration was defined as RV1 and OPV given on the same day;staggered administration as RV1 and OPV given > 1 day apart. Rotavirus seroconversion was defined as a 4-fold rise in immunoglobulin A titer from before the first RV1 dose to >= 3 weeks after the second RV1 dose. Results. There were no significant differences in baseline RV1 immunogenicity among the 409 infants included in the final analysis. Infants who received RV1 and OPV concomitantly, regardless of OPV formulation, were less likely to seroconvert (47%;95% confidence interval, 39%-54%) than those who received both vaccines staggered >= 1 day (63%;57%-70%;P <.001). For staggered administration, we found no evidence that the interval between RV1 and OPV administration affected RV1 immunogenicity. Conclusions. Coadministration of monovalent, bivalent, or trivalent OPV seems to lower RV1 immunogenicity.

关键词： poliovirus   epidemiology   genetic diversity   North Waziristan   Pakistan  

摘要： Background. Despite tremendous efforts in the fight against polio, Pakistan bears the highest proportion of poliomyelitis cases among the 3 endemic countries including Afghanistan and Nigeria. Apart from insecurity and inaccessibility challenges, the substantial shift of unimmunized children from North Waziristan due to recent military operations was presumed to favor the widespread poliovirus infection in Pakistan. Methods. To better understand the current epidemiological situation, we analyzed the virologic data of wild poliovirus type 1 (WPV1) strains detected in Pakistan during 2013-2015. Results. Five genetic clusters (A-E) were identified with at least 5% nucleotide divergence in the viral protein 1 (VP1) coding region. Peshawar, Quetta, and Karachi were found to be the major endemic foci where multiple discrete genetic lineages of WPV1 were detected. Phylogenetic analysis suggests that wild poliovirus strains from endemic regions were genetically distant (with 5%-15% VP1 nucleotide divergence) from those detected in North Waziristan cases, excluding the possibility of a recent progenitor of WPV1 instigating single-source transmission across the country. Orphan lineages detected in Rawalpindi, Lahore, Hyderabad, Sukkur, and Jacobabad revealed silent transmission and the need for vigilant surveillance. Sustenance of analogous genetic lineages over a period of 3 years highlights multiple unimmunized foci present to maintain viral genetic diversity. Conclusions. Our findings are inconsistent with the hypothesis that impoverished populations from North Waziristan serve as a possible determinant of widespread poliomyelitis infection in Pakistan and further emphasize the need to scale-up clinical and environmental surveillance as well as immunization activities.

关键词： OPV   IPV   Poliovirus   Circulation   Outbreak  

摘要： There was a substantial difference in coverage rate between the first and the second round even though the second round was done at the sites with the highest circulation of WPV in sewage and in spite of the efforts of the Ministry of Health with its public campaign. Since January 2014, Israel's MoH has also adopted the addition of 2 supplementary rounds of bOPV at ages 6 and 18 months to the routine IPV based immunization program.1 The actions taken following the detection of WPV1 in sewage, resulted in the gradual decline of WPV1 in sewage samples since September 2013 that led to complete disappearance of the virus. [...]the bOPV based SIA conducted in Israel, probably provided adequate booster responses in IPV vaccinated children.

关键词： Inactivated poliovirus vaccine   Oral poliovirus vaccine   Shedding   Serum neutralizing antibody   Intestinal immunity   Poliomyelitis  

摘要： Background: The Polio Endgame strategy includes phased withdrawal of oral poliovirus vaccines (OPV) coordinated with introduction of inactivated poliovirus vaccine (IPV) to ensure population immunity. The impact of IPV introduction into a primary OPV series of immunizations in a developing country is uncertain. Methods: Between May 2011 and November 2012, we enrolled 700 Bangladeshi infant-mother dyads from Dhaka slums into an open-label randomized controlled trial to test whether substituting an injected IPV dose for the standard Expanded Program on Immunization (EPI) fourth tOPV dose at infant age 39 weeks would reduce fecal shedding and enhance systemic immunity. The primary endpoint was mucosal immunity to poliovirus at age one year, measured by fecal excretion of any Sabin virus at five time points up to 25 days post-52 week tOPV challenge, analyzed by the intention to treat principle. Findings: We randomized 350 families to the tOPV and IPV vaccination arms. Neither study arm resulted in superior intestinal protection at 52 weeks measured by the prevalence of infants shedding any of three poliovirus serotypes, but the IPV dose induced significantly higher seroprevalence and seroconversion rates. This result was identical for poliovirus detection by cell culture or RT-qPCR. The non-significant estimated culture-based shedding risk difference was -3% favoring IPV, and the two vaccination schedules were inferred to be equivalent within a 95% confidence margin of -10% to +4%. Results for shedding analyses stratified by poliovirus type were similar. Conclusions: Neither of the vaccination regimens is superior to the other in enhancing intestinal immunity as measured by poliovirus shedding at 52 weeks of age and the IPV regimen provides similar intestinal immunity to the four tOPV series, although the IPV regimen strongly enhances humoral immunity. The IPV-modified regimen may be considered for vaccination programs without loss of intestinal protection. (C) 2015 The

关键词： Research Article  

摘要： Background The "gold standard" for assessing mucosal immunity after vaccination with poliovirus vaccines consists in measuring virus excretion in stool after challenge with oral poliovirus vaccine (OPV). This testing is time and resource intensive, and development of alternative methods is a priority for accelerating polio eradication. We therefore evaluated circulating antibody-secreting cells (ASCs) as a potential means to evaluate mucosal immunity to poliovirus vaccine. Methods 199 subjects, aged 10 years, and previously immunized repeatedly with OPV, were selected. Subjects were assigned to receive either a booster dose of inactivated poliovirus vaccine (IPV), bivalent OPV (bOPV), or no vaccine. Using a micro-modified whole blood-based ELISPOT assay designed for field setting, circulating poliovirus type-specific IgA- and IgG-ASCs, including gut homing alpha 4 beta 7+ASCs, were enumerated on days 0 and 7 after booster immunization. In addition, serum samples collected on days 0, 28 and 56 were tested for neutralizing antibody titers against poliovirus types 1, 2, and 3. Stool specimens were collected on day 28 (day of bOPV challenge), and on days 31, 35 and 42 and processed for poliovirus isolation. Results An IPV dose elicited blood IgA- and IgG-ASC responses in 84.8 to 94.9% of subjects, respectively. In comparison, a bOPV dose evoked corresponding blood ASC responses in 20.0 to 48.6% of subjects. A significant association was found between IgA- and IgG-ASC responses and serum neutralizing antibody titers for poliovirus type 1, 2, 3 (p<0.001). In the IPV group, alpha 4 beta 7(+)ASCs accounted for a substantial proportion of IgA-ASCs and the proportion of subjects with a positive alpha 4 beta 7(+) IgA-ASC response to poliovirus types 1, 2 and 3 was 62.7%, 89.8% and 45.8%, respectively. A significant association was observed between virus excretion and alpha 4 beta 7(+) IgA-and/or IgG-ASC responses to poliovirus type 3 among immunized children;however, only a we

关键词： 脊髓灰质炎   吸附无细胞百白破灭活脊髓灰质炎和b型流感嗜血杆菌(结合)联合疫苗   口服脊髓灰质炎减毒活疫苗   中和抗体  

摘要： 目的观察吸附无细胞百白破灭活脊髓灰质炎和b型流感嗜血杆菌(结合)联合疫苗(DTaP-IPV/Hib五联疫苗,简称五联苗)基础免疫后的脊髓灰质炎(简称脊灰)中和抗体水平,并与传统的口服脊灰减毒活疫苗(oral poliomyelitis attenuated live vaccine,OPV)免疫效果对比分析。方法选择无脊灰疫苗接种禁忌证的健康婴儿,按照接种疫苗的不同,分为五联苗组和OPV组,每组100人。收集每个研究对象的脐带血和基础免疫后的颈静脉血,以微量中和试验测定血清中脊灰病毒Ⅰ、Ⅱ、Ⅲ型中和抗体。将抗体几何平均滴度(geometric mean titer,GMT)进行对数转换,采用t检验、χ2检验比较免疫前后抗体水平差异。结果基础免疫后,两组Ⅰ、Ⅱ、Ⅲ型脊灰中和抗体水平较免疫前均有显著提高(P<0.01),保护率均达100%。五联苗组基础免疫后Ⅰ、Ⅱ、Ⅲ型脊灰中和抗体GMT分别为227.54、186.11、377.41,OPV组分别为1 217.75、680.29、418.77,两组Ⅰ、Ⅱ型抗体水平差异有统计学意义,五联苗低于OPV组(Ⅰ型:t=-10.80,P<0.01;Ⅱ型:t=-8.941,P=0.010);Ⅲ型抗体水平差异无统计学意义(t=-0.624,P=0.776)。基础免疫后Ⅰ、Ⅱ、Ⅲ型脊灰中和抗体水平与性别、出生体重、母传抗体水平无线性相关关系,Ⅰ、Ⅱ型抗体水平与采血间隔和接种疫苗的种类有线性相关关系。结论五联苗3剂次基础免疫后可提供针对脊灰的有效免疫保护,但Ⅰ、Ⅱ型抗体水平相对于OPV免疫后较低,建议对基础免疫时全程接种五联苗的儿童在4岁加强免疫时口服1剂次OPV。

关键词： 疫苗   监测   冷链  

摘要： 目的了解辽宁省脊髓灰质炎（脊灰）疫苗在冷链运转中各个环节的效价变化,评价该省冷链系统管理质量。方法采用跟踪监测法,按照省→市→县→乡→村运苗顺序,逐级随机抽取同一批号脊灰减毒活疫苗。脊灰疫苗效价测定采用微量细胞培养病变法。结果辽宁省2008~2014年脊灰疫苗效价介于5.5~6.4 log CCID50/m L之间,脊灰疫苗质量总合格率为89.2%（合格滴度为≥5.7 log CCID_（50）/m L）,各级采样点脊灰疫苗效价均值与省级冷库进行比较,乡镇级接种点与省级冷库效价均值有显著性差异（t=2.154,P〈0.05）,其它均无显著性差异,2009年脊灰疫苗效价均值为7年最低值,但各级采样点与省级冷库进行比较差异均无统计学意义,2009年的两个监测点脊灰疫苗效价均值差异有统计学意义（P〈0.05）。结论脊灰疫苗效价监测对冷链系统质量评价有重要意义,应加强基层接种单位的冷链建设及对接种医生的培训,保证疫苗质量,从而降底疫苗针对传染病的发病率。

关键词： 口服脊髓灰质炎减毒活疫苗   疫苗相关病例   特征  

摘要： 目的了解脊髓灰质炎活疫苗相关麻痹型病例的发病特征。方法对1例相关麻痹型病例的临床和流行病学资料进行分析。结果病例首次服脊髓灰质炎减毒活疫苗21天后出现双下肢麻痹,病例患肛周脓肿,便标本分离出脊灰疫苗株病毒,麻痹60天后随访有残留麻痹。结论建议将肛周脓肿作为脊髓灰质炎减毒活疫苗接种的禁忌证。

关键词： POLIOVIRUS   ENTEROVIRUSES   FLACCID dysarthria   PHYLOGENY   POLIO vaccination  

摘要： To assess the dynamics of genetic reversion of live poliovirus vaccine in humans, we studied molecular evolution in Sabin-like poliovirus isolates from Nigerian acute flaccid paralysis cases obtained from routine surveillance. We employed a novel modeling approach to infer substitution and recombination rates from whole-genome sequences and information about poliovirus infection dynamics and the individual vaccination history. We confirmed observations from a recent vaccine trial that VP1 substitution rates are increased for Sabin-like isolates relative to the rate for the wild type due to increased nonsynonymous substitution rates. We also inferred substitution rates for attenuating nucleotides and confirmed that reversion can occur in days to weeks after vaccination. We combine our observations for Sabin-like virus evolution with the molecular clock for VP1 of circulating wild-type strains to infer that the mean time from the initiating vaccine dose to the earliest detection of circulating vaccine-derived poliovirus (cVDPV) is 300 days for Sabin-like virus type 1, 210 days for Sabin-like virus type 2, and 390 days for Sabin-like virus type 3. Phylogenetic relationships indicated transient local transmission of Sabin-like virus type 3 and, possibly, Sabin-like virus type 1 during periods of low wild polio incidence. Comparison of Sabin-like virus recombinants with known Nigerian vaccine-derived poliovirus recombinants shows that while recombination with non-Sabin enteroviruses is associated with cVDPV, the recombination rates are similar for Sabin isolate-Sabin isolate and Sabin isolate non-Sabin enterovirus recombination after accounting for the time from dosing to the time of detection. Our study provides a comprehensive picture of the evolutionary dynamics of the oral polio vaccine in the field.