Nasopharyngeal Type-I Interferon for Immediately Available Prophylaxis Against Emerging Respiratory Viral Infections

Pharmacodynamic of Recombinant Human Interferon Alpha-2b Nasal Drops and Effective Prophylaxis Against SARS-COV-2 Infection

The recombinant human interferon alpha-2b (IFN-α2b) nasal drop formulation (Nasalferon) was studied as prophylaxis for SARS-CoV-2. Healthy volunteers between 19 and 80 years of age received 0.5 million international units of IFN in one drop (0.05 mL ) in each nostril, twice a day, for 10 consecutive days. The nondetection of SARS-CoV-2 by real-time polymerase chain reaction was the primary outcome variable. Several IFN-α biomarkers, including intranasal gene expression and innate immune effector activity, were increased in participants who received intranasal IFN-α2b. The study included 2,930 international travelers and 5,728 persons who were their close contacts. The subjects were treated with Nasalferon in January 2021, and 9,162 untreated travelers were included as controls. COVID-19 rate in treated subjects was significantly lower than in untreated subjects (0.05% vs. 4.84%). The proportion of travelers with COVID-19 decreased from 60.9% to 2.2% between December 2020 and February 2021. Furthermore, 1,719 tourism workers also received Nasalferon, and no cases of SARS-CoV-2 infection were detected, whereas 39 COVID-19 cases (10.6%) were reported in 367 untreated subjects. The main adverse events associated with the use of intranasal IFN-α2b were nasal congestion, headache, and rhinorrhea. Our prophylactic health interventions study demonstrates that the daily administration of Nasalferon for 10 days decreases the risk of developing COVID-19 in healthy volunteers. [Figure: see text].

Safety and Non-Inferiority Evaluation of Two Immunization Schedules with an Inactivated SARS-CoV-2 Vaccine in Adults: A Randomized Clinical Trial

Several vaccines have been developed to control the COVID-19 pandemic. CoronaVac®, an inactivated SARS-CoV-2 vaccine, has demonstrated safety and immunogenicity, preventing severe COVID-19 cases. We investigate the safety and non-inferiority of two immunization schedules of CoronaVac® in a non-inferiority trial in healthy adults. A total of 2302 healthy adults were enrolled at 8 centers in Chile and randomly assigned to two vaccination schedules, receiving two doses with either 14 or 28 days between each. The primary safety and efficacy endpoints were solicited adverse events (AEs) within 7 days of each dose, and comparing the number of cases of SARS-CoV-2 infection 14 days after the second dose between the schedules, respectively. The most frequent local AE was pain at the injection site, which was less frequent in participants aged ≥60 years. Other local AEs were reported in less than 5% of participants. The most frequent systemic AEs were headache, fatigue, and myalgia. Most AEs were mild and transient. There were no significant differences for local and systemic AEs between schedules. A total of 58 COVID-19 cases were confirmed, and all but 2 of them were mild. No differences were observed in the proportion of COVID-19 cases between schedules. CoronaVac® is safe, especially in ≥60-year-old participants. Both schedules protected against COVID-19 hospitalization.

Advances in the Prophylaxis of Respiratory Infections by the Nasal and the Oromucosal Route: Relevance to the Fight with the SARS-CoV-2 Pandemic

In this time of COVID-19 pandemic, the strategies for prevention of the infection are a primary concern. Looking more globally on the subject and acknowledging the high degree of misuse of protective face masks from the population, we focused this review on alternative pharmaceutical developments eligible for self-defense against respiratory infections. In particular, the attention herein is directed to the nasal and oromucosal formulations intended to boost the local immunity, neutralize or mechanically "trap" the pathogens at the site of entry (nose or mouth). The current work presents a critical review of the contemporary methods of immune- and chemoprophylaxis and their suitability and applicability in topical mucosal dosage forms for SARS-CoV-2 prophylaxis.

Exploiting natural antiviral immunity for the control of pandemics: Lessons from Covid-19

The outbreak of coronavirus disease 2019 (COVID-19), triggered by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the disruptive global consequences in terms of mortality and social and economic crises, have taught lessons that may help define strategies to better face future pandemics. Innate and intrinsic immunity form the front-line natural antiviral defense. They involve both tissue-resident and circulating cells, which can produce anti-viral molecules shortly after viral infection. Prototypes of these factors are type I interferons (IFN), antiviral cytokines with a long record of clinical use. During the last two years, there has been an impressive progress in understanding the mechanisms of both SARS-CoV-2 infection and the cellular and soluble antiviral responses occurring early after viral exposure. However, this information was not sufficiently translated into therapeutic approaches. Insufficient type I IFN activity probably accounts for disease progression in many patients. This results from both the multiple interfering mechanisms developed by SARS-CoV-2 to decrease type I IFN response and various pre-existing human deficits of type I IFN activity, inherited or auto-immune. Emerging data suggest that IFN-I-mediated boosting of patients' immunity, achieved directly through the exogenous administration of IFN-β early post viral infection, or indirectly following inoculation of heterologous vaccines (e.g., Bacillus Calmette Guerin), might play a role against SARS-CoV-2. We review how recent insights on the viral and human determinants of critical COVID-19 pneumonia can foster clinical studies of IFN therapy. We also discuss how early therapeutic use of IFN-β and prophylactic campaigns with live attenuated vaccines might prevent a first wave of new pandemic viruses.

Molecularly Imprinted Hydrogels Selective to Ribavirin as New Drug Delivery Systems to Improve Efficiency of Antiviral Nucleoside Analogue: A Proof-of-Concept Study with Influenza A Virus

This study describes the synthesis and evaluation of different imprinted hydrogels using ribavirin as template molecule. Ribavirin serves as a model molecule because it possesses a broad-spectrum antiviral effect against RNA viruses, which are expected as emerging viruses. The choice of monomers enables to stabilize the pre-polymerization complex and to synthesize biocompatible polymers. Predictive studies as well as experimental works conclude similar results on best ribavirin:monomers ratios. Thus, materials exhibit high selective cavities toward ribavirin. These affinities allow to show release profiles drastically different from the non-imprinted ones at two temperatures. The imprinted materials show a sustained profile able to release antiviral for more than 24 h. The hydrogels obtained are biocompatible with model cells retained, human lung epithelial BEAS-2B cells. Cell viability is excellent and pro-inflammatory response is insignificant when imprinted polymers are incubated with cells. Finally, viral tests carried out on Influenza A infected lung cells show that imprinted delivery systems delivering 1 to 3 µg of antiviral have the same efficiency as a medium containing 30 µg mL^-1 of active agent. As a very interesting result, the molecularly imprinted polymers as drug delivery systems allow to increase the local concentration of antiviral, to improve their delivery when its bioavailability is low.