ABSTRACT
Background. Mucosal vaccination may offer increased protection against SARS-CoV-2 compared to parental immunization. Here, we describe immunogenicity and efficacy following viral challenge in non-human primates after intranasal delivery of three unique non-replicating adenoviral vector vaccine (rAd5) candidates. Methods. African green monkeys (AMG) were prime boost immunized 29 days apart with vaccine candidates either expressing the parental spike protein alone (Wuhan-S), spike plus nucleocapsid(Wuhan-S-N), or the spike protein fromthe beta variant (beta-S). Serumand nasal swabs were collected every 14 days and humoral responses to full length spike (S) and receptor binding domain (RBD) were assessed.AllAMGs were challenged with SARS-CoV-2 B.1.351 (beta variant)onday 56. Viral loadsmeasured every two days by TCID50 in nasal washes and bronchial lavage fluid post challenge. Results. Mucosal immunization with Wuhan-S induced significant increases in serum IgG and IgA responses against the homologous parental lineage, as well as beta, delta, and omicron variants. In nasal samples, Wuhan-S immunization elicited over 500-fold increases in in cross-reactive IgA against multiple variants of concern including delta and omicron. While the beta-S rAd5 vaccine candidate induced enhanced serum IgG responses to homologous S and RBD proteins, this approach resulted in less cross-reactive antibodies to other variants compared to Wuhan-S rAd5 vaccine. Despite the differences in the ability to elicit cross-reactive antibody responses, all vaccinated AMGs challenged with SARS-CoV-2 B.1.351 (beta variant), had a significant reduction in viral titers by TCID50 in the nasal passages and reduced viral load in bronchial lavage fluid compared to unvaccinated controls. Conclusion. These results demonstrate mucosal administration of rAd5 clinical candidate vaccine, Wuhan-S, is immunogenic and offers cross-protective humoral responses in both serum and nasal compartments against a mismatched SARS-CoV-2 challenge virus.
ABSTRACT
Introduction: Hyperinflammation plays an important role in severe COVID-19. Using inconsistent criteria, researchers define hyperinflammation as a form of very severe inflammation with cytokine storm. Our paper gives a novel definition. Subsequently, we describe the treatment of ICU-patients with COVID-19 requiring ECMO and/or mechanical ventilation. Methods: We searched scientific articles on P2X7 purinergic receptors (P2X7Rs) to underpin our definition of hyperinflammation. We found that lidocaine can block P2X7Rs. The issue is that the halfmaximal effective concentration of lidocaine for P2X7R inhibition is much higher than the maximal tolerable plasma concentration. To overcome this, we selectively inhibit the P2X7Rs of the cells of the lymph nodes. We do this by subdermal infusion of lidocaine HCL inducing clonal expansion of Tregs in local lymph nodes. Secondarily, these Tregs migrate throughout the body suppressing systemic hyperinflammation (Fig. 1). We treated six COVID-19 ICU-patients with subdermal lidocaine infusion (1 mg/kg/h). Results: We found 437 articles to underpin our definition of hyperinflammation. The essence is that hyperinflammation is initiated when SARS-CoV-2 infection causes prolonged and vigorous activation of the P2X7Rs of the immune cells. This leads to cytokine storm and desensitisation of purinergic receptors of immune cells other than the P2X7Rs, resulting in immune paralysis with secondary infections. The six ICU-patients with COVID-19 we treated with lidocaine all recovered completely. Conclusions: Applying consistent criteria, we defined hyperinflammation as prolonged and vigorous activation of P2X7Rs of the immune cells and established that selective inhibition of these receptors can calm down cytokine storm in COVID-19. Our experience with subdermal administration of lidocaine in the ICU made clear that this method may not be suitable outside hospitals. Therefore, we developed a novel oral transmucosal administration route using xylocaine 10% spray, as shown in the Figure. (Figure Presented).