Background 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. Methods 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. Results 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. Conclusion 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.

Healthy adults typically display enhanced processing for self-(relative to other-) relevant and positive (relative to negative) information. However, it is unclear whether these two biases interact to form a selfpositivity bias, whereby self-positive information receives prioritized processing. It is also unclear how a blocked versus mixed referent design impacts reference and valence processing. We addressed these questions using behavioral and electrophysiological indices across two studies using a Self-Referential Encoding Task, followed by surprise recall and recognition tasks. Early (P1) and late (LPP) event-related potentials were time-locked to a series of trait adjectives, encoded relative to oneself or a fictional character, with referent presented in a blocked (Exp. 1) or mixed (Exp. 2) trial design. Regardless of study design, participants recalled and recognized more self-than other-relevant adjectives, and recognized more positive than negative adjectives. Additionally, participants demonstrated larger LPP amplitudes for self-relevant and positive adjectives. The LPP self-relevance effect emerged earlier and persisted longer in the blocked (400-800ms) versus mixed design (600-800ms). The LPP valence effect was not apparent in the blocked design, but appeared late in the mixed design (600-1200ms). Critically, the interaction between self-relevance and valence appeared only behaviorally in the mixed design, suggesting that overall self-relevance and valence independently impact neural socio-cognitive processing.

No abstract

No abstract

No abstract