HIV Molecular Epidemiology Laboratory, Microbiology Department, Ramón y Cajal University Hospital-IRYCIS-CIBERESp-RITIP-CoRISpe, Carretera de Colmenar, Km.9, 100, 28034, Madrid, Spain.
Microbiology Department, Ramón y Cajal University Hospital, Madrid, Spain.
Sci Rep. 2022 May 13;12(1):7920. doi: 10.1038/s41598-022-12052-4.
Child vaccination reduces infant mortality rates. HIV-infected children present higher risk of diseases than non-infected. We report the protection coverage rates for 6 vaccine-preventable diseases in a paediatric population from the Democratic Republic of the Congo (DRC) and the impact of HIV infection, providing the first data on the validity of dried blood samples (DBS) to monitor the immune protection. During 2016-2018 DBS from 143 children/adolescents were collected in Kinshasa (DRC), being 52 HIV-infected. Forty-two had a paired plasma sample. Protective IgG was quantified (VirClia-IgG,VIRCELL) to obtain the optimal cut-off in IgG detection in DBS. ROC curves were generated with R software and statistical analyses with Stata. Protective IgG levels varied across pathogens, not reaching herd immunity. HIV-infected presented lower vaccine protection than uninfected for all analyzed pathogens, except rubella, with statistically significant differences for measles (30.8% vs. 53.8%; p = 0.008) and tetanus (3.8% vs. 22%; p = 0.0034). New cut-offs were calculated when using DBS to improve test performance. We reinforce the necessity to increase pediatric vaccination coverage in Kinshasa, especially in HIV seropositive, with less capacity to maintain adequate antibody levels. DBS were useful to monitor vaccination coverage in seroprevalence studies in resource-limited settings, after optimizing the cut-off value for each pathogen.
儿童疫苗接种可降低婴儿死亡率。感染 HIV 的儿童比未感染的儿童患疾病的风险更高。我们报告了刚果民主共和国（DRC）儿科人群中 6 种疫苗可预防疾病的保护率，以及 HIV 感染的影响，这是首次提供有关干燥血斑（DBS）监测免疫保护效力的有效性数据。2016-2018 年，在金沙萨（DRC）采集了 143 名儿童/青少年的 DBS，其中 52 名为 HIV 感染者。其中 42 人有配对的血浆样本。通过 VirClia-IgG（VIRCELL）定量检测保护性 IgG，以获得 DBS 中 IgG 检测的最佳截断值。使用 R 软件生成 ROC 曲线，并使用 Stata 进行统计分析。病原体之间的保护性 IgG 水平各不相同，未达到群体免疫。除风疹外，与未感染者相比，所有分析的病原体中 HIV 感染者的疫苗保护率均较低，麻疹（30.8%对 53.8%；p=0.008）和破伤风（3.8%对 22%；p=0.0034）差异具有统计学意义。当使用 DBS 来提高检测性能时，计算了新的截断值。我们强调需要增加金沙萨的儿科疫苗接种覆盖率，特别是在 HIV 血清阳性率较高的地区，因为他们保持足够抗体水平的能力较弱。在资源有限的环境中进行血清流行率研究时，DBS 可用于监测疫苗接种覆盖率，优化每个病原体的截断值后，效果更好。
