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BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused millions of infections and fatalities globally since its emergence in late 2019. The virus was first detected in Finland in January 2020, after which it rapidly spread among the populace in spring. However, compared to other European nations, Finland has had a low incidence of SARS-CoV-2. To gain insight into the origins and turnover of SARS-CoV-2 lineages circulating in Finland in 2020, we investigated the phylogeographic and -dynamic history of the virus.MethodsThe origins of SARS-CoV-2 introductions were inferred via Travel-aware Bayesian time-measured phylogeographic analyses. Sequences for the analyses included virus genomes belonging to the B.1 lineage and with the D614G mutation from countries of likely origin, which were determined utilizing Google mobility data. We collected all available sequences from spring and fall peaks to study lineage dynamics.ResultsWe observed rapid turnover among Finnish lineages during this period. Clade 20C became the most prevalent among sequenced cases and was replaced by other strains in fall 2020. Bayesian phylogeographic reconstructions suggested 42 independent introductions into Finland during spring 2020, mainly from Italy, Austria, and Spain.ConclusionsA single introduction from Spain might have seeded one-third of cases in Finland during spring in 2020. The investigations of the original introductions of SARS-CoV-2 to Finland during the early stages of the pandemic and of the subsequent lineage dynamics could be utilized to assess the role of transboundary movements and the effects of early intervention and public health measures.

The most recent SARS-CoV-2 variant of concern, Omicron (Pango lineage B.1.1.529), was first detected in South Africa (1), although it might have emerged elsewhere, and has since spread globally at [...]

Autoimmune polyendocrinopathy‐candidiasis‐ectodermal dystrophy (APECED) is an inborn error of immunity affecting both multiple endocrine organs and susceptibility to candidiasis, each with an autoimmune basis. Recently, high titer neutralizing anti‐type I interferon (IFN) autoantibodies have been linked with increased severity of SARS‐CoV‐2 and varicella zoster virus infections in APECED patients. Examining immunity against cytomegalovirus (CMV), we found a higher prevalence of anti‐CMV IgG antibodies in patients with APECED (N = 19) than in 44 healthy controls (90% vs 64%, p = 0.04); the similar difference in their IgG levels did not achieve significance (95 ± 74 vs 64 ± 35 IU/mL, ns.). In contrast, the frequency of CMV‐specific T cells was lower (804 ± 718/million vs 1591 ± 972/million PBMC p = 0.03). We saw no correlations between levels of anti‐CMV IgG and anti‐IFN antibodies in APECED patients or in a separate cohort of patients with thymoma (n = 70), over 60% of whom also had anti‐IFN antibodies. Our results suggest a dysregulated response to CMV in APECED patients and highlight immunodeficiency to viral infections as part of the disease spectrum. [ABSTRACT FROM AUTHOR]

Several new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged globally, most notably variants of concern Alpha (B.1.1.7) (1), Beta (B1.351) (2), Gamma (P.1) (3), and most [...]

Lyme borreliosis, caused by Borrelia burgdorferi sensu lato, is the most common tickborne disease. Its neuronal form, neuroborreliosis, comprises 3 to 38% of borreliosis cases in Europe. Borrelia outer surface proteins and virulence factors, OspE and BBK32, have been previously reported to help cause infection by promoting attachment to human host epithelial cells and evading complement attack. We assessed the serological responses to BBK32 and OspE in 19 individuals diagnosed with neuroborreliosis to see whether antibodies that could both target the bacteria and neutralize the virulence mechanisms on the microbial surface emerge. Results evaluate levels of total protein, IgG and the chemokine CXCL13, a determinant for B‐cell recruitment during neuroinflammation, in patients' cerebrospinal fluid samples. Antibody levels against BBK32 and OspE correlated with those against VlsE, a well‐characterized diagnostic serological marker of the disease. A dual serological profile of the patients was observed. K‐means clustering split the cohort into two discrete groups presenting distinct serological and CNS responses. One group contained young patients with low levels of anti‐BBK32 and OspE antibodies. The other group showed stronger responses, possibly following prolonged infections or reinfections. Additionally, we assessed anti‐ganglioside antibodies that could cause autoimmunity or complement dysregulation but observed that they did not correlate with neuroborreliosis in our patient cohort. The dual nature of antibody responses against the virulence factors BBK32 and OspE in neuroborreliosis patients may suggest the necessity of repeated exposures for efficient immune responses. Better protection could be achieved if the virulence factors were formulated into vaccines. [ABSTRACT FROM AUTHOR]

Neisseria gonorrhoeae is the causative agent of gonorrhea, a disease that is restricted to humans. Complement forms a key arm of the innate immune system that combats gonococcal infections. N. gonorrhoeae uses its outer membrane porin (Por) molecules to bind the classical pathway of complement down-regulatory protein C4b-binding protein (C4bp) to evade killing by human complement. Strains of N. gonorrhoeae that resisted killing by human serum complement were killed by serum from rodent, lagomorph, and primate species, which cannot be readily infected experimentally with this organism and whose C4bp molecules did not bind to N. gonorrhoeae. In contrast, we found that Yersinia pestis, an organism that can infect virtually all mammals, bound species-specific C4bp and uniformly resisted serum complement-mediated killing by these species. Serum resistance of gonococci was restored in these sera by human C4bp. An exception was serotype Por1B-bearing gonococcal strains that previously had been used successfully in a chimpanzee model of gonorrhea that simulates human disease. Por1B gonococci bound chimpanzee C4bp and resisted killing by chimpanzee serum, providing insight into the host restriction of gonorrhea and addressing why Por1B strains, but not Por1A strains, have been successful in experimental chimpanzee infection. Our findings may lead to the development of better animal models for gonorrhea and may also have implications in the choice of complement sources to evaluate neisserial vaccine candidates. complement | gonorrhea