Office of the Vice Provost for Undergraduate Education, Stanford University, Stanford, California, USA.
Department of Comparative Medicine, Stanford University School of Medicine, Stanford, California, USA.
J Glob Health. 2022 Feb 26;12:05009. doi: 10.7189/jogh.12.05009. eCollection 2022.
The COVID-19 pandemic caused by SARS-CoV-2 exposed a global problem, as highly effective vaccines are challenging to produce and distribute, particularly in regions with limited resources and funding. As an alternative, immunoglobulins produced in eggs of immunized hens (IgY) can be a simple and inexpensive source for a topical and temporary prophylaxis. Here, we developed a method to extract and purify IgY antibodies from egg yolks of hens immunized against viral pathogen-derived proteins using low-cost, readily available materials, for use in resource-limited settings.
Existing protocols for IgY purification and equipment were modified, including extraction from yolks and separation of water-soluble IgY using common household reagents and tools. A replacement for a commercial centrifuge was developed, using a home food processor equipped with a 3D printed adapter to enable IgY precipitation. IgY purification was verified using standard gel electrophoresis and Western blot analyses.
We developed a step-by-step protocol for IgY purification for two settings in low- and middle-income countries (LMIC): a local laboratory, where commercial centrifuges are available, or a more rural setting, where an alternative for expensive centrifuges can be used. Gel electrophoresis and Western blot analyses confirmed that the method produced highly enriched IgY preparation; each commercial egg produced ~ 90 mg of IgY. We also designed a kit for IgY production in these two settings and provided a cost estimate of the kit.
IgY purified from eggs of immunized local hens can offer a fast and affordable prophylaxis, provided that purification can be performed in a resource-limited setting. Here, we created a low-cost method that can be used anywhere where electricity is available using inexpensive, readily available materials in place of costly, specialized laboratory equipment and chemicals. This procedure can readily be used now to make an anti-SARS-CoV-2 prophylaxis in areas where vaccines are unavailable, and can be modified to combat future threats from viral epidemics and pandemics.
由 SARS-CoV-2 引起的 COVID-19 大流行暴露了一个全球性问题，因为高效疫苗的生产和分发具有挑战性，尤其是在资源和资金有限的地区。作为替代方案，用免疫母鸡的卵生产的免疫球蛋白（IgY）可以成为一种简单且廉价的局部和临时预防的来源。在这里，我们开发了一种从针对病毒病原体衍生蛋白免疫的母鸡卵黄中提取和纯化 IgY 抗体的方法，该方法使用低成本、易于获得的材料，适用于资源有限的环境。
修改了现有的 IgY 纯化方案和设备，包括使用常见的家用试剂和工具从蛋黄中提取以及分离水溶性 IgY。开发了一种替代商用离心机的设备，使用配备有 3D 打印适配器的家用食品处理器来实现 IgY 沉淀。使用标准凝胶电泳和 Western blot 分析验证了 IgY 纯化。
我们为中低收入国家（LMIC）的两个环境制定了 IgY 纯化的分步方案：一个是有商用离心机的本地实验室，另一个是更偏远的环境，可以使用昂贵离心机的替代设备。凝胶电泳和 Western blot 分析证实，该方法产生了高度富集的 IgY 制剂；每个商用鸡蛋可产生约 90 毫克的 IgY。我们还为这两种环境设计了 IgY 生产试剂盒，并提供了试剂盒的成本估算。
从免疫本地母鸡的卵中纯化的 IgY 可以提供快速且负担得起的预防措施，前提是在资源有限的环境中可以进行纯化。在这里，我们创建了一种低成本的方法，可以在任何有电力的地方使用廉价、易于获得的材料代替昂贵的、专门的实验室设备和化学品。现在，该程序可以迅速用于在疫苗不可用的地区生产抗 SARS-CoV-2 预防制剂，并可以修改以应对未来由病毒流行和大流行引起的威胁。
