Pediatric nasal epithelial cells are less permissive to SARS-CoV-2 replication compared to adult cells

Children typically experience more mild symptoms of COVID-19 when compared to adults. There is a strong body of evidence that children are also less susceptible to SARS-CoV-2 infection with the ancestral viral isolate. However, the emergence of SARS-CoV-2 variants of concern (VOCs) has been associated with an increased number of pediatric infections. Whether this is the result of widespread adult vaccination or fundamental changes in the biology of SARS-CoV-2 remains to be determined. Here, we use primary nasal epithelial cells from children and adults, differentiated at an air-liquid interface to show that the ancestral SARS-CoV-2 replicates to significantly lower titers in the nasal epithelial cells of children compared to those of adults. This was associated with a heightened antiviral response to SARS-CoV-2 in the nasal epithelial cells of children. Importantly, the Delta variant also replicated to significantly lower titres in the nasal epithelial cells of children. This trend was markedly less pronounced in the case of Omicron. It is also striking to note that, at least in terms of viral RNA, Omicron replicated better in pediatric NECs compared to both Delta and the ancestral virus. Taken together, these data show that the nasal epithelium of children supports lower infection and replication of ancestral SARS-CoV-2, although this may be changing as the virus evolves.

Interferon-a2b treatment for COVID-19

BackgroundThe global pandemic of COVID-19 cases caused by infection with SARS-CoV-2 is ongoing, with no approved antiviral intervention. We describe here the effects of treatment with interferon-2b in a cohort of confirmed COVID-19 cases in Wuhan, China. MethodsIn this retrospective study, 77 adults hospitalized with confirmed COVID-19 were treated with either nebulized IFN-2b (5mU b.i.d.), arbidol (200mg t.i.d.) or a combination of IFN-2b plus arbidol. Serial SARS-CoV-2 testing along with hematological measurements, including cell counts and blood biochemistry, serum cytokine levels, temperature and blood oxygen saturation levels were recorded for each patient during their hospital stay. ResultsTreatment with IFN-2b with or without arbidol significantly reduced the duration of detectable virus in the upper respiratory tract and in parallel reduced duration of elevated blood levels for the inflammatory markers IL-6 and CRP. ConclusionThese findings suggest that IFN-2b should be further investigated as a therapy in COVID-19 cases.

Perinatal Immunization With Vaccine-Grade Listeria monocytogenes Provides Protection Against Murine Th2 Airway Inflammation

PURPOSE: Asthma is a chronic respiratory disorder that leads to inflammation and narrowing of the airways. Its global prevalence has attained epidemic levels and treatment options that reach beyond temporary relief of symptoms are urgently needed. Since the processes leading to clinically symptomatic asthma start early in life, we set out to systematically evaluate a neonatal immunotherapeutic based on Listeria monocytogenes (Lm) for the control of allergic sensitization. METHODS: We modified Lm to express the model allergen, ovalbumin (OVA), and tested the ability of neonatal immunization with this strain to control allergic sensitization in a mouse model of OVA-induced asthma. Mice were immunized as newborns with live or heat killed LmOVA or live Lm, followed 6 weeks later by allergic sensitization with OVA. In order to determine whether the T(H)1-polarizing effect of this vaccine vector inadvertently may exacerbate development of certain T(H)1-driven allergic diseases, mice immunized as newborns were assessed in a model of adult hypersensitivity pneumonitis (HP). RESULTS: Both LmOVA and Lm-control vaccines were highly effective in providing long-lasting protection from airway inflammation after only one immunization given perinatally. Serum antibody levels and lung cytokine production suggest that this prophylactic strategy is associated with an allergen specific T(H)1-dominated response. Specifically, LmOVA vaccinated mice displayed significantly elevated OVA-specific serum IgG2a, but no difference in anti-OVA IgE antibodies and only slightly decreased anti-OVA IgG1 antibodies. Importantly, Lm-based neonatal vaccination did not exacerbate Th1/Th17 driven HP, arguing against broad spectrum immune skewing. CONCLUSIONS: Our findings highlight the promise of early life Lm-based immunomodulatory interventions as a prophylactic strategy for allergic asthma.

Perinatal Immunization With Vaccine-Grade Listeria monocytogenes Provides Protection Against Murine Th2 Airway Inflammation

PURPOSE: Asthma is a chronic respiratory disorder that leads to inflammation and narrowing of the airways. Its global prevalence has attained epidemic levels and treatment options that reach beyond temporary relief of symptoms are urgently needed. Since the processes leading to clinically symptomatic asthma start early in life, we set out to systematically evaluate a neonatal immunotherapeutic based on Listeria monocytogenes (Lm) for the control of allergic sensitization. METHODS: We modified Lm to express the model allergen, ovalbumin (OVA), and tested the ability of neonatal immunization with this strain to control allergic sensitization in a mouse model of OVA-induced asthma. Mice were immunized as newborns with live or heat killed LmOVA or live Lm, followed 6 weeks later by allergic sensitization with OVA. In order to determine whether the T(H)1-polarizing effect of this vaccine vector inadvertently may exacerbate development of certain T(H)1-driven allergic diseases, mice immunized as newborns were assessed in a model of adult hypersensitivity pneumonitis (HP). RESULTS: Both LmOVA and Lm-control vaccines were highly effective in providing long-lasting protection from airway inflammation after only one immunization given perinatally. Serum antibody levels and lung cytokine production suggest that this prophylactic strategy is associated with an allergen specific T(H)1-dominated response. Specifically, LmOVA vaccinated mice displayed significantly elevated OVA-specific serum IgG2a, but no difference in anti-OVA IgE antibodies and only slightly decreased anti-OVA IgG1 antibodies. Importantly, Lm-based neonatal vaccination did not exacerbate Th1/Th17 driven HP, arguing against broad spectrum immune skewing. CONCLUSIONS: Our findings highlight the promise of early life Lm-based immunomodulatory interventions as a prophylactic strategy for allergic asthma.