AM3, a natural glycoconjugate, as adjuvant treatment for COVID-19 patients

We have been immersed in the COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for two years, and the availability of drugs for its treatment remains limited. Both in the general population and in patients, one of the most effective tools to prevent viral infections or limit their impact is strengthening the immune system. AM3, a polysaccharide/protein compound, has shown regulatory effects on the immune system. In this study, we have evaluated the potential effect of AM3/probiotic for the treatment of COVID-19 patients. We have included 83 patients with mild-moderate SARS-CoV-2 infection that were randomly assigned to receive either AM3/probiotic or placebo. All patients filled a 32-item questionnaire, which assesses symptom burden over a 2-week period. Blood samples were also obtained to investigate immune response by flow cytometry. The administration of AM3/probiotics decreased the number of symptoms and their intensities (Total score after 1 month: 11.0 (1.0-20.3) vs 24.0 (12.0-61.00)) in ambulatory patients with COVID-19, and the length of hospital stay in those that required hospitalization with respect to those receiving placebo (5.8±0.7 vs 6.4 ±1.4 days). In general, the treatment with AM3/probiotic did not affect CD4+ T cells, including Th1, Th2, and Th17 cells. By contrast, central memory (CM) and effector memory (EM) CD8+ T lymphocytes showed a significant increment after the AM3/probiotic treatment that was not observed in patients receiving placebo. Conclusions: Our data suggest the beneficial use of AM3/probiotics supplementation in the treatment of patients with COVID-19. Further studies will confirm these findings and investigate the mechanisms.