COVID-19 is an acute respiratory infection accompanied by pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has affected millions of people globally. To date, there are no highly efficient therapies for this infection. Probiotic bacteria can interact with the gut microbiome to strengthen the immune system, enhance immune responses, and induce appropriate immune signaling pathways. Several probiotics have been confirmed to reduce the duration of bacterial or viral infections. Immune fitness may be one of the approaches by which protection against viral infections can be reinforced. In general, prevention is more efficient than therapy in fighting viral infections. Thus, probiotics have emerged as suitable candidates for controlling these infections. During the COVID-19 pandemic, any approach with the capacity to induce mucosal and systemic reactions could potentially be useful. Here, we summarize findings regarding the effectiveness of various probiotics for preventing virus-induced respiratory infectious diseases, especially those that could be employed for COVID-19 patients. However, the benefits of probiotics are strain-specific, and it is necessary to identify the bacterial strains that are scientifically established to be beneficial.

No abstract

No abstract

Brucellosis vaccines are designed to induce the cellular immunity. An effective brucellosis vaccine is one that could induce both cellular and humoral immunity. Serum Bactericidal Assay(SBA) is an important method for the determination of vaccine humoral immunity. This study is the first to observe humoral immunity in brucellosis by SBA. Extracted B.abortus LPS and OMP’s were injected to rabbits. Group1 injected by 25µg of LPS, Group2 injected by 50µg of OMP ‘s and Group3 injected by 1ml of combined vaccine, 3 times every 2 weeks. The Groups were challenged with B.abortus 544 in the second injection. Sera were separated 2 weeks after the last injection. SBA was performed, each well was streak cultured into a plate of Brucella Agar. Colony count was done for each plate. Results have shown, the third injection of the combined vaccine, had the highest titer of 1/64, and the efficacy of the vaccine was %87.71.