孟加拉国国际腹泻病研究中心Firdausi Qadri团队研究了孟加拉国城市儿童接种Vi破伤风类毒素结合疫苗预防伤寒的效果。相关论文发表在2021年8月9日出版的《柳叶刀》杂志上。
伤寒仍然是中低收入国家发病和死亡的一个主要原因。世卫组织建议在高负担国家实施Vi-破伤风类毒素结合疫苗（Vi-TT）接种计划，但几乎没有证据表明它在此类环境中能有效预防临床伤寒。
研究组在孟加拉国达卡的一个城市流行环境中进行了一项参与者盲、观察者盲的集群随机试验，且在此之前进行了一项安全试验。研究组共招募了150个集群，每个集群约有1350名居民，将其按1：1随机分组，分别接种Vi-TT或SA 14-14-2型日本脑炎（JE）疫苗。通过父母或监护人邀请9个月至16岁以下的儿童，根据其居住群单次接种疫苗。研究人群平均随访17.1个月。在意向治疗的疫苗接种人群或集群的所有居民中，评估的主要终点是通过Vi-TT对血液培养证实的伤寒的总体保护。
2018年4月至5月，共有41344名儿童接种了疫苗，另外20412名儿童在2018年9月至12月和2019年4月至5月期间的补救性疫苗接种运动中接种了疫苗。JE疫苗接种者中的伤寒发病率为每10万人-年635例，Vi-TT疫苗接种者为每10万人-年96例，Vi-TT的总体保护率为85%。不同年龄组的总疫苗保护是一致的，包括2岁以下接种疫苗的儿童（81%）。JE疫苗集群所有居民中的伤寒发病率为每10万人-年213例，Vi-TT疫苗集群为每10万人-年93例，Vi-TT总体保护率为57%。研究组没有观察到Vi-TT间接疫苗的显著保护作用（19%）。疫苗耐受性良好，未观察到与疫苗相关的严重不良事件。
研究结果表明，9个月至16岁以下的儿童接种Vi-TT疫苗可有效预防伤寒。
附：英文原文
Title: Protection by vaccination of children against typhoid fever with a Vi-tetanus toxoid conjugate vaccine in urban Bangladesh: a cluster-randomised trial
Author: Firdausi Qadri, Farhana Khanam, Xinxue Liu, Katherine Theiss-Nyland, Prasanta Kumar Biswas, Amirul Islam Bhuiyan, Faisal Ahmmed, Rachel Colin-Jones, Nicola Smith, Susan Tonks, Merryn Voysey, Yama F Mujadidi, Olga Mazur, Nazmul Hasan Rajib, Md Ismail Hossen, Shams Uddin Ahmed, Arifuzzaman Khan, Nazia Rahman, Golap Babu, Melanie Greenland, Sarah Kelly, Mahzabeen Ireen, Kamrul Islam, Peter OReilly, Karin Sofia Scherrer, Virginia E Pitzer, Kathleen M Neuzil, K Zaman, Andrew J Pollard, John D Clemens
Issue&Volume: 2021-08-09
Abstract:
Background
Typhoid fever remains a major cause of morbidity and mortality in low-income and middle-income countries. Vi-tetanus toxoid conjugate vaccine (Vi-TT) is recommended by WHO for implementation in high-burden countries, but there is little evidence about its ability to protect against clinical typhoid in such settings.
Methods
We did a participant-masked and observer-masked cluster-randomised trial preceded by a safety pilot phase in an urban endemic setting in Dhaka, Bangladesh. 150 clusters, each with approximately 1350 residents, were randomly assigned (1:1) to either Vi-TT or SA 14-14-2 Japanese encephalitis (JE) vaccine. Children aged 9 months to less than 16 years were invited via parent or guardian to receive a single, parenteral dose of vaccine according to their cluster of residence. The study population was followed for an average of 17·1 months. Total and overall protection by Vi-TT against blood culture-confirmed typhoid were the primary endpoints assessed in the intention-to-treat population of vaccinees or all residents in the clusters. A subset of approximately 4800 participants was assessed with active surveillance for adverse events. The trial is registered at www.isrctn.com, ISRCTN11643110.
Findings
41344 children were vaccinated in April–May, 2018, with another 20412 children vaccinated at catch-up vaccination campaigns between September and December, 2018, and April and May, 2019. The incidence of typhoid fever (cases per 100000 person-years) was 635 in JE vaccinees and 96 in Vi-TT vaccinees (total Vi-TT protection 85%; 97·5% CI 76 to 91, p<0·0001). Total vaccine protection was consistent in different age groups, including children vaccinated at ages under 2 years (81%; 95% CI 39 to 94, p=0·0052). The incidence was 213 among all residents in the JE clusters and 93 in the Vi-TT clusters (overall Vi-TT protection 57%; 97·5% CI 43 to 68, p<0·0001). We did not observe significant indirect vaccine protection by Vi-TT (19%; 95% CI 12 to 41, p=0·20). The vaccines were well tolerated, and no serious adverse events judged to be vaccine-related were observed.
Interpretation
Vi-TT provided protection against typhoid fever to children vaccinated between 9 months and less than 16 years. Longer-term follow-up will be needed to assess the duration of protection and the need for booster doses.
DOI: 10.1016/S0140-6736(21)01124-7
Source: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)01124-7/fulltext
LANCET：《柳叶刀》，创刊于1823年。隶属于爱思唯尔出版社，最新IF：202.731
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投稿链接：http://ees.elsevier.com/thelancet
本期文章：《柳叶刀》：Online/在线发表
