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COVID-19 pandemic, caused by the SARS-CoV-2 virus, is still affecting the entire world via the rapid emergence of new contagious variants. Vaccination remains the most effective prevention strategy for viral infection, yet not all countries have sufficient access to vaccines due to limitations in manufacturing and transportation. Thus, there is an urgent need to develop an easy-to-use, safe, and low-cost vaccination approach. Genetically modified microorganisms, especially probiotics, are now commonly recognized as attractive vehicles for delivering bioactive molecules via oral and mucosal routes. In this study, Lactobacillus casei has been selected as the oral vaccine candidate based on its’ natural immunoadjuvant properties and the ability to resist acidic gastric environment, to express antigens of SARS-CoV-2 Omicron variant B.1.1.529 with B-cell and T-cell epitopes. This newly developed vaccine, OMGVac, was shown to elicit a robust IgG systemic immune response against the spike protein of Omicron variant B.1.1.529 in Golden Syrian hamsters. No adverse effects were found throughout this study, and the overall safety was evaluated in terms of physiological and histopathological examinations of different organs harvested. In addition, this study illustrated the use of the recombinant probiotic as a live delivery vector in the initiation of systemic immunity, which shed light on the future development of next-generation vaccines to combat emerging infectious diseases.

Objective: To evaluate the efficacy and safety of pegylated interferon-α2b and lamivudine combination therapy for chronic hepatitis B. Design: Randomized, controlled, open-label trial. Setting: Outpatient clinic in a referral center. Participants: 100 treatment-naive patients with hepatitis B antigen (HBeAg)--positive chronic hepatitis B and moderately elevated alanine aminotransferase levels. Measurement: The primary end point was sustained virologic response (HBeAg seroconversion and HBV DNA level < 500 000 copies/mL) at 24 weeks after cessation of treatment. Intervention: A staggered regimen of combination therapy with pegylated interferon-α2b (1.5 μg/kg of body weight per week; maximum, 100 μg) given for 32 weeks plus lamivudine (100 mg daily) given for 52 weeks versus lamivudine (100 mg daily) monotherapy given for 52 weeks. Of the 100 participants, 96% completed treatment and 80% completed post-treatment follow-up. Results: The rate of sustained virologic response was 36% for the combination treatment group and 14% for the lamivudine monotherapy group (absolute difference, 22 percentage points [95% Cl, 6 to 38 percentage points]). End-of-treatment outcomes showed that, compared with monotherapy, patients receiving combination therapy more often had virologic response (60% vs. 28% [absolute difference, 32 percentage points (Cl, 14 to 50 percentage points)]); had more substantial reductions of HBV DNA (3.91 log10 copies/mL vs. 2.83 log10 copies/mL); and less often had lamivudine-resistant mutants (21% vs. 40%). The per centages of patients with normalization of alanine aminotransferase levels and histologic improvement did not differ. Adverse effects, such as transient influenza-like symptoms, alopecia, and local erythematous reactions, were more common with combination therapy. Limitations: This study lacked a double-blind design and was conducted at 1 institution. Because of the staggered pegylated interferon--lamivudine regimen, patients assigned to combination therapy received treatment for 8 weeks longer than those assigned to monotherapy. Conclusions: In patients with HBeAg-positive chronic hepatitis B, staggered combination treatment with pegylated interferon-α2b and lamivudine may lead to a higher rate of virologic response than lamivudine monotherapy. [ABSTRACT FROM AUTHOR]