Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi.
Graduate Program in Life Sciences, University of Maryland School of Medicine, Baltimore, MD, USA.
Hum Vaccin Immunother. 2024 Dec 31;20(1):2384760. doi: 10.1080/21645515.2024.2384760. Epub 2024 Sep 12.
Vaccine safety and immunogenicity data in human immunodeficiency virus (HIV)-exposed uninfected (HEU) children are important for decision-making in HIV and typhoid co-endemic countries. In an open-label study, we recruited Malawian HEU and HIV unexposed uninfected (HUU) infants aged 9 - 11 months. HEU participants were randomized to receive Vi-tetanus toxoid conjugate vaccine (Vi-TT) at 9 months, Vi-TT at 15 months, or Vi-TT at 9 and 15 months. HUU participants received Vi-TT at 9 and 15 months. Safety outcomes included solicited and unsolicited adverse events (AE) and serious AEs (SAEs) within 7 days, 28 days, and 6 months of vaccination, respectively. Serum was collected before and at day 28 after each vaccination to measure anti-Vi IgG antibodies by enzyme-linked immunosorbent assay (ELISA). Cohort 1 (66 participants) enrollment began 02 December 2019, and follow-up was terminated before completion due to the COVID-19 pandemic. Cohort 2 (100 participants) enrollment began 25 March 2020. Solicited AEs were mostly mild, with no significant differences between HEU and HUU participants or one- and two-dose groups. All six SAEs were unrelated to vaccination. Anti-Vi geometric mean titers (GMT) increased significantly from 4.1 to 4.6 ELISA units (EU)/mL at baseline to 2572.0 - 4117.6 EU/mL on day 28 post-vaccination, and similarly between HEU and HUU participants for both one- and two-dose schedules. All participants seroconverted (>4-fold increase in GMT) by the final study visit. Our findings of comparable safety and immunogenicity of Vi-TT in HUU and HEU children support country introductions with single-dose Vi-TT in HIV-endemic countries.
疫苗安全性和免疫原性数据对于艾滋病毒和伤寒双重流行国家的决策具有重要意义。在一项开放性标签研究中,我们招募了马拉维的艾滋病毒暴露但未感染(HEU)和未暴露但未感染(HUU)的 9-11 月龄婴儿。HEU 参与者被随机分配在 9 月龄时接种 Vi-破伤风类毒素结合疫苗(Vi-TT),在 15 月龄时接种,或在 9 和 15 月龄时接种。HUU 参与者在 9 和 15 月龄时接种 Vi-TT。安全性结局包括分别在接种后 7 天、28 天和 6 个月内出现的有症状和无症状不良事件(AE)和严重不良事件(SAE)。分别在每次接种前和接种后第 28 天采集血清,通过酶联免疫吸附试验(ELISA)测量抗 Vi IgG 抗体。第 1 队列(66 名参与者)于 2019 年 12 月 2 日开始入组,由于 COVID-19 大流行,在完成前提前终止了随访。第 2 队列(100 名参与者)于 2020 年 3 月 25 日开始入组。有症状 AE 主要为轻度,HEU 和 HUU 参与者或单剂和双剂组之间无显著差异。所有 6 例 SAE 均与疫苗接种无关。抗 Vi 几何平均滴度(GMT)从基线时的 4.1 至 4.6 ELISA 单位(EU)/mL 显著增加至接种后第 28 天的 2572.0 至 4117.6 EU/mL,HEU 和 HUU 参与者在单剂和双剂方案中相似。所有参与者在最后一次研究访问时均血清转化(GMT 增加 4 倍以上)。我们发现 HUU 和 HEU 儿童接种 Vi-TT 的安全性和免疫原性相当,支持在艾滋病毒流行国家引入单剂 Vi-TT。