Niu Mimi, Mu Yi, Adriko Moses, Candia Rowel, Jones Malcolm K, McManus Donald P, Egwang Thomas G, Cai Pengfei
Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
School of Life Science, Hainan University, Haikou, China.
Front Public Health. 2024 Nov 18;12:1437063. doi: 10.3389/fpubh.2024.1437063. eCollection 2024.
The coronavirus disease 2019 (COVID-19) pandemic has resulted in devastating health and economic consequences worldwide. Vaccination has been a central pillar for COVID-19 prevention and control. Understanding the immunomodulatory effects of helminth infections on COVID-19 vaccine-induced immune responses and vaccine efficacy is crucial to the development and deployment of effective vaccination strategies in low- and middle-income countries with a high prevalence of worms.
In September 2022, we conducted a cross-sectional, population-based survey in five endemic villages in Mayuge District, Uganda ( = 450). The prevalence of schistosomiasis and soil-transmitted helminths was determined by the Kato-Katz (KK) technique on two stool samples collected from each participant. A subset of individuals ( = 204) were interviewed in a COVID-19 vaccination survey. IgG levels against the SARS-CoV-2 spike S1 subunit (anti-S1 IgG) were measured by enzyme-linked immunosorbent assay (ELISA) in collected serum samples.
The overall schistosomiasis and hookworm prevalence rates in the five villages were 36.4% (166/450) and 36.9% (168/450), respectively. Within the cohort, 69.78% (314/450) of the subjects had a positive anti-S1 IgG response. COVID-19 vaccination coverage among the interviewed participants was 93.14% (190/204; 95% CI, 88.8% - 95.9%). However, 81% (154/190) of COVID-19 vaccinees had an anti-S1 IgG titre ≤200. In an adolescent group receiving a single dose of the BNT162b2 mRNA vaccine ( = 23), an inverse correlation was observed between anti-S1 IgG antibody level/titre and faecal egg count. Within the above group, anti-S1 IgG levels/titres were significantly lower in subjects with moderate or heavy infection ( = 5) than those in KK-negative individuals ( = 9).
Although the acceptance rate of COVID-19 vaccination was high, the majority of participants received only a single vaccine dose and the overall anti-S1 IgG titres in confirmed vaccinees were low. Moderate-to-heavy schistosome infections blunted the antibody responses following vaccination with a single dose of BNT162b2. These observations confirm the necessity for a second COVID-19 vaccine dose for two-dose primary immunization series and call for implementation research that may inform the development of a 'treat and vaccinate' policy during vaccination roll-out in regions with heavy worm burdens.
2019年冠状病毒病（COVID-19）大流行在全球范围内造成了毁灭性的健康和经济后果。疫苗接种一直是COVID-19预防和控制的核心支柱。了解蠕虫感染对COVID-19疫苗诱导的免疫反应和疫苗效力的免疫调节作用，对于在蠕虫高流行的低收入和中等收入国家制定和实施有效的疫苗接种策略至关重要。
2022年9月，我们在乌干达马尤盖区的五个流行村庄开展了一项基于人群的横断面调查（n = 450）。通过改良加藤厚涂片法（Kato-Katz法）对每个参与者采集的两份粪便样本进行检测，以确定血吸虫病和土源性蠕虫的流行率。在一项COVID-19疫苗接种调查中，对一部分个体（n = 204）进行了访谈。采用酶联免疫吸附测定（ELISA）法检测所采集血清样本中针对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）刺突S1亚基的IgG水平（抗S1 IgG）。
五个村庄的血吸虫病和钩虫总体流行率分别为36.4%（166/450）和36.9%（168/450）。在该队列中，69.78%（314/450）的受试者抗S1 IgG反应呈阳性。接受访谈的参与者中COVID-19疫苗接种覆盖率为93.14%（190/204；95%置信区间，88.8% - 95.9%）。然而，81%（154/190）的COVID-19疫苗接种者抗S1 IgG滴度≤200。在接受单剂BNT162b2 mRNA疫苗的青少年组（n = 23）中，观察到抗S1 IgG抗体水平/滴度与粪便虫卵计数呈负相关。在上述组中，中度或重度感染（n = 5）的受试者抗S1 IgG水平/滴度显著低于加藤厚涂片法阴性个体（n = 9）。
尽管COVID-19疫苗接种接受率较高，但大多数参与者仅接种了一剂疫苗，确诊的疫苗接种者总体抗S1 IgG滴度较低。中度至重度血吸虫感染减弱了单剂BNT162b2疫苗接种后的抗体反应。这些观察结果证实了两剂基础免疫系列中第二剂COVID-疫苗的必要性，并呼吁开展实施研究，为在蠕虫负担较重地区的疫苗接种推广过程中制定“治疗与接种”政策提供参考。
