An Open Label Non-inferiority Trial Assessing Vibriocidal Response of a Killed Bivalent Oral Cholera Vaccine Regimen following a Five Year Interval in Kolkata, India
An Open Label Non-inferiority Trial Assessing Vibriocidal Response of a Killed Bivalent Oral Cholera Vaccine Regimen following a Five Year Interval in Kolkata, India
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DOI：
10.1371/journal.pntd.0003809
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发表时间：
2015-05-01
影响因子：
3.8
通讯作者：
Wierzba, Thomas F.
中科院分区：
文献类型：
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作者：
Kanungo, Suman;Desai, Sachin N.;Wierzba, Thomas F.
背景二价灭活口服霍乱疫苗 (OCV) 在五年内提供 65% 的累积保护。目前尚不清楚加强方案是否可以维持对先前免疫人群的保护。本研究检验了初次给药后 5 年内给予 OCV 方案的免疫原性和安全性。方法/主要发现 在之前参加过一项大型疗效试验的 426 名健康印度参与者中进行了一项开放标签对照试验。为了评估五年后给予的 OCV 方案是否能引起与初级系列相同的抗体反应，我们比较了接受两剂加强方案的先前免疫参与者与接受初级两剂免疫系列的参与者的杀弧菌抗体滴度。在接受两剂 OCV 主要系列的参与者 (n = 186) 中，69% (95% CI 62%-76%) 发生血清转化。在干预组 (n = 184) 中，66% (95% CI 59%-73%) 在初始系列后五年内进行两次剂量加强计划后出现血清转化。单次加强剂量后，71% (95% CI 64%-77%) 发生血清转化。儿童在初次治疗和加强治疗后分别表现出 79% (95% CI 69%-86%) 和 82% (95% CI 73%-88%) 的血清转化率。 结论/意义 OCV 加强治疗方案引起的免疫反应与在流行地区接受初次系列治疗的免疫反应类似。尽管单次加强剂量会引起强烈的免疫反应，但仍需要进一步研究来衡量这些发现是否可以转化为临床保护。
BackgroundThe bivalent killed oral cholera vaccine (OCV) provides 65% cumulative protection over five years. It remains unknown whether a boosting regimen can maintain protection in previously immunized populations. This study examines the immunogenicity and safety of an OCV regimen given five years following initial dosing.Methodology/Principal FindingsAn open label controlled trial was conducted in 426 healthy Indian participants previously enrolled in a large efficacy trial. To assess whether an OCV regimen given after five years can elicit an antibody response equal to that of a primary series, we compared vibriocidal antibody titers in previously immunized participants receiving a two dose booster regimen to participants receiving a primary two dose immunization series. Among participants receiving a two dose primary series of OCV (n = 186), 69% (95% CI 62%-76%) seroconverted. In the intervention arm (n = 184), 66% (95% CI 59%-73%) seroconverted following a two dose boosting schedule given five years following the initial series. Following a single boosting dose, 71% (95% CI 64%-77%) seroconverted. Children demonstrated 79% (95% CI 69%-86%) and 82% (95% CI 73%-88%) seroconversion after primary and boosting regimens, respectively.Conclusions/SignificanceAdministration of an OCV boosting regimen elicits an immune response similar to those receiving a primary series in endemic areas. Though a single boosting dose induces a strong immune response, further investigations are needed to measure if these findings translate to clinical protection.