Uffe Vest Schneider’s research while affiliated with University of Copenhagen and other places

This study presents findings captured in the first 1.5 years of the Virus Monitoring in Denmark (VMD) surveillance system. It describes trends in respiratory viruses, related symptoms, and participant demographics and behaviors. VMD used self‐swabbing and self‐reported symptoms to monitor respiratory viruses in the general population. Participants were recruited via digital invitations to a representative sample of the population or through workplaces. Symptomatic participants could self‐swab and register their samples and report their symptoms via a dedicated smartphone web app. With 30 627 participants and 12 642 samples analyzed, VMD had a broad demographic representation. SARS‐CoV‐2 was the most frequently detected virus, with positivity rates peaking at over 50% in late 2023. Participants commonly self‐swabbed because of fever, cough, and rhinorrhea, with influenza A linked to the highest median number of symptoms. Participants only provided samples after reaching a specific symptom threshold, and participation affected the health‐seeking behaviors and work attendance of a few individuals. VMD continuously provided real‐time insights into respiratory virus trends and symptomatology in the general non‐healthcare‐seeking population. Its accessibility – available to anyone with a Danish identification number, a smartphone, and an invitation – highlights its potential as a pandemic preparedness tool.

Background and Aims Chronic hepatitis C virus (HCV) infection afflicts around 50 million people globally, causing ~250,000 deaths yearly. An effective vaccine needs to overcome high viral diversity and HCV’s ability to evade neutralizing antibodies (NAbs). Rapid antigenic drift in the N-terminal motif of envelope protein E2, named hypervariable region 1 (HVR1), is critically involved in NAb evasion via an incompletely understood mechanism involving viral entry factors. The canonical length of HVR1 is 27 amino acids, but insertions of 2-4 amino acids was described in patients infected with genotype 1b. We aimed at determining whether HVR1 insertions may be underreported due to extreme HVR1 variability. Approach and Results We observed a 0.7% HVR1 insertion prevalence in routine NGS patient contigs. Thus, we performed direct sequence analysis of E1E2 sequences from 131 HCV infected patients. Interestingly, we observed that 3% of patients harbored viruses (genotype 1a, 2b, 3a) with dominant HVR1 insertions. Insertion of longer non-canonical HVR1s into HCV cell culture recombinants frequently caused loss of fitness. However, culture-viable viruses with HVR1 insertions were fully viable in vivo . Interestingly, in adapted genotype 1b recombinants with HVR1 insertions, we found internal HVR1 deletions, that increased antibody sensitivity, which surprisingly correlated more with reduced LDLr than reduced SR-BI dependency, indicating a role of LDLr in NAb evasion. Conversely, HVR1 insertions had no effect on receptor dependency, however, they modulated epitope-specific NAb sensitivity. Conclusions HVR1 insertion prevalence and NAb sensitivity modulation indicate they represent a mechanism by which HCV evades emerging NAbs during infection.

Highly mutated SARS-CoV-2 Omicron subvariant BA.2.86 emerged in July 2023. We investigated the neutralisation of isolated virus by antibodies induced by earlier infection or vaccination. The neutralisation titres for BA.2.86 were comparable to those for XBB.1 and EG.5.1, by antibodies induced by XBB.1.5 or BA.4/5 breakthrough infection or BA.4/5 vaccination.

Background: SARS-CoV-2 may affect the male reproductive system as it uses angiotensin-converting enzyme [ACE]2, which is expressed in testicular tissue, as an entry point into the cell. Few studies have evaluated the long-term effects of mild COVID-19 on testicular function, and INSL3 levels have not previously been assessed during acute SARS-CoV-2 infection. Objectives: To assess the impact of acute SARS-CoV-2 infection on testicular function including INSL3 and the presence of SARS-CoV-2 RNA in semen in non-hospitalised men with mild COVID-19. Materials and methods: This longitudinal study included 36 non-hospitalised SARS-CoV-2-positive men (median age 29 years). Inclusion was within seven days following a positive SARS-CoV-2 RT-PCR test. Reproductive hormone levels, semen parameters, and the presence of SARS-CoV-2 RNA in oropharyngeal and semen samples were assessed during acute SARS-CoV-2 infection (baseline) and at three- and six-month follow-up. Wilcoxon matched-pair signed-rank (two samples) test was used to assess time-related alterations in reproductive hormone levels and semen parameters. Results: Lower plasma testosterone [T] (total and calculated free [c-fT]) and higher LH concentrations were observed during acute SARS-CoV-2 infection (baseline) compared to three- and six-month follow-up. Consequently, ratios of c-fT/LH were lower at baseline compared to three- and six-month follow-up (P < 0.001 and P = 0.003, respectively). Concomitantly, lower INSL3 concentrations were observed at baseline compared to three-month follow-up (P = 0.01). The total number of motile spermatozoa was also lower at baseline compared to six-month follow-up (P = 0.02). The alterations were detected irrespective of whether the men had experienced SARS-CoV-2-related fever episodes or not. No SARS-CoV-2 RNA was detected in semen at any time point. Discussion and conclusion: This study showed a reduction in testicular function, which was for the first time confirmed by INSL3, in men mildly affected by SARS-CoV-2 infection. The risk of transmission of SARS-CoV-2 RNA via semen seems to be low. Febrile episodes may impact testicular function, but a direct effect of SARS-CoV-2 cannot be excluded. This article is protected by copyright. All rights reserved.