Background: The coronavirus disease 2019 (COVID-19) is a respiratory disease caused by SARS-CoV-2, a recently discovered strain of coronavirus. The virus has spread rapidly, causing millions of death worldwide. Contrary to the predictions, prevalence and mortality due to COVID-19 have remained moderate on the African continent. Several factors, including age, genetics, vaccines, and co-infections, might impact the course of the pandemic in Africa. Helminths are highly endemic in Sub-Saharan Africa and are renowned for their ability to evade, skew, and suppress human immune responses through various immune-modulatory mechanisms. Such effects will likely impact SARS-CoV-2 transmission and disease progression. Methods: Here, we analyzed in vitro the impact of antigen extracts from three major helminth parasites, including Onchocerca volvulus, Brugia malayi, and Ascaris lumbricoides, on the immune reactivity to SARS-CoV-2 peptides in COVID-19 patients. Activation of CD4⁺ and CD8⁺ T cells was investigated using flow cytometry to monitor the expression of CD137 (4-1BB) and CD69. Cytokine expression, including IL-6, IL-10, IFN-γ, and TNFα, was measured by Luminex in cell culture supernatants. Results: We observed that helminth antigens significantly reduced the frequency of SARS-CoV-2-reactive CD4⁺ T helper cells. In contrast, the expression of SARS-CoV-2-reactive CD8⁺ T cells was not affected and even significantly increased when PBMCs from COVID-19 patients living in Benin, an endemic helminth country, were used. In addition, stimulation with helminth antigens was associated with increased IL-10 and a reduction of IFNγ and TNFα. Conclusions: Our data offer a plausible explanation for the moderate incidence of COVID-19 in Africa and support the hypothesis that helper T cell-mediated immune responses to SARS-CoV-2 are mitigated in the presence of helminth antigens, while virus-specific cytotoxic T cell responses are maintained.

Almost two years after remdesivir was approved and extensively used in numerous clinical studies for the treatment of COVID-19 patients, there is still no clear recommendation for the time and phase of the disease of remdesivir administration. This retrospective observational study included adults (≥18 years) with severe COVID-19, radiologically confirmed pneumonia, a need for supplemental oxygen and an interval from symptom onset to enrolment of 10 days or less. All patients were treated with remdesivir for 5 to 10 days, or with clinical improvement within that period. The primary goal was the outcome in patients treated with remdesivir during the early stage of the disease considering the different disease severity. The median time from symptom onset to treatment was 8.4 days (3–10). Clinical improvements and good outcomes were observed in 104 of 137 patients (75.9%); 33 (24.1%) of 137 patients died. Subgroup analyses showed that the mortality rate was significantly lower in moderately ill patients (3 out of 51 patients; 5.9%) than in the group of severely/critically ill patients (30 out of 86 patients; 34.8%; p < 0.005). Older age, rise of CRP and CT score were shown to be significant predictors of disease outcome. Overall, remdesivir was well tolerated, and the treatment was discontinued in only four patients. The results of this observational study in 137 patients with different disease severity contribute to the attitude concerning remdesivir administration in the early stage of COVID-19, at least in moderately ill patients with a high risk of progression, before the transition to a more severe stage.

Bolest uzrokovana SARS-CoV-2 (COVID-19) izrazito je zarazna bolest, koja zadnje tri godine ima izuzetno loš utjecaj na svjetsku demografiju, rezultirajući s gotovo 6,5 milijuna umrlih diljem svijeta. U ovom trenutku još uvijek ne postoji učinkoviti...