Orthopoxvirus-specific antibodies wane to undetectable levels 1 year after MVA-BN vaccination of at-risk individuals, the Netherlands, 2022 to 2023.

In response to the mpox outbreak in 2022 and 2023, widespread vaccination with modified vaccinia Ankara-Bavarian Nordic (MVA-BN, also known as JYNNEOS or Imvanex) was initiated. Here, we demonstrate that orthopoxvirus-specific binding and MVA-neutralising antibodies waned to undetectable levels 1 year post vaccination in at-risk individuals who received two doses of MVA-BN administered subcutaneously with an interval of 4 weeks, without prior smallpox or mpox vaccination. Continuous surveillance is essential to understand the impact of declining antibody levels.

Scenarios of future mpox outbreaks among men who have sex with men: a modelling study based on cross-sectional seroprevalence data from the Netherlands, 2022.

BackgroundFollowing the 2022-2023 mpox outbreak, crucial knowledge gaps exist regarding orthopoxvirus-specific immunity in risk groups and its impact on future outbreaks.AimWe combined cross-sectional seroprevalence studies in two cities in the Netherlands with mathematical modelling to evaluate scenarios of future mpox outbreaks among men who have sex with men (MSM).MethodsSerum samples were obtained from 1,065 MSM attending Centres for Sexual Health (CSH) in Rotterdam or Amsterdam following the peak of the Dutch mpox outbreak and the introduction of vaccination. For MSM visiting the Rotterdam CSH, sera were linked to epidemiological and vaccination data. An in-house developed ELISA was used to detect vaccinia virus (VACV)-specific IgG. These observations were combined with published data on serial interval and vaccine effectiveness to inform a stochastic transmission model that estimates the risk of future mpox outbreaks.ResultsThe seroprevalence of VACV-specific antibodies was 45.4% and 47.1% in Rotterdam and Amsterdam, respectively. Transmission modelling showed that the impact of risk group vaccination on the original outbreak was likely small. However, assuming different scenarios, the number of mpox cases in a future outbreak would be markedly reduced because of vaccination. Simultaneously, the current level of immunity alone may not prevent future outbreaks. Maintaining a short time-to-diagnosis is a key component of any strategy to prevent new outbreaks.ConclusionOur findings indicate a reduced likelihood of large future mpox outbreaks among MSM in the Netherlands under current conditions, but emphasise the importance of maintaining population immunity, diagnostic capacities and disease awareness.

Looking back on the COVID-19 pandemic in an elite sports team using whole genome sequencing.

OBJECTIVES: The aim of this study was to investigate the effectiveness of infection control measures to prevent transmission of SARS-CoV-2 within a professional sports team using whole genome sequencing. DESIGN: Prospective cohort study. METHODS: 74 players and staff members of a Dutch professional male football team were followed from August 2020 until May 2021. A set of health and safety measures were introduced and all participants underwent regular SARS-CoV-2 RNA testing. All positive samples were subsequently sequenced (Nanopore sequencing) to assess whether infections were acquired within the training center or in the community. RESULTS: Throughout the study period, 13 participants tested positive for SARS-CoV-2. The phylogenetic analysis revealed 2 clusters (of 2 and 3 cases respectively), indicating that 3/13 cases (23%) acquired infection from another player or staff member. The first cluster was diagnosed upon enrolment, thus transmission had occurred prior to the implementation of health and safety protocols. Finally, 4 cases were diagnosed prior to symptom onset, emphasizing that frequent testing leads to early detection and isolation. CONCLUSIONS: These data show that a combination of regular testing and basic control measures can prevent outbreaks of COVID-19 in a professional sports team. Whole genome sequencing is an important tool to distinguish between infections introduced from the community and infections transmitted between athletes.

Brain stem encephalitis is a rare complication of COVID-19.

Here, we describe the clinical phenotype of SARS-CoV-2-related CNS disease and evaluate the SARS-CoV-2 antibody index as a tool to differentiate between a direct (viral) and indirect etiology. Out of >4000 hospitalized patients with COVID-19, we included 13 patients with neurological symptoms with suspicion of neuroinflammation. On clinical grounds, eight were classified as having a possible/probable relationship between neurological symptoms and COVID-19. A clinically distinctive phenotype of brainstem and cerebellar symptoms was seen in 6/8 patients. As we found a positive SARS-CoV-2 antibody index in 3/5 patients, indicating specific intrathecal SARS-CoV-2 IgG production, a direct link with SARS-CoV-2 is likely.

Low levels of monkeypox virus-neutralizing antibodies after MVA-BN vaccination in healthy individuals.

In July 2022, the ongoing monkeypox (MPX) outbreak was declared a public health emergency of international concern. Modified vaccinia Ankara-Bavarian Nordic (MVA-BN, also known as Imvamune, JYNNEOS or Imvanex) is a third-generation smallpox vaccine that is authorized and in use as a vaccine against MPX. To date, there are no data showing MPX virus (MPXV)-neutralizing antibodies in vaccinated individuals nor vaccine efficacy against MPX. Here we show that MPXV-neutralizing antibodies can be detected after MPXV infection and after historic smallpox vaccination. However, a two-shot MVA-BN immunization series in non-primed individuals yields relatively low levels of MPXV-neutralizing antibodies. Dose-sparing of an MVA-based influenza vaccine leads to lower MPXV-neutralizing antibody levels, whereas a third vaccination with the same MVA-based vaccine significantly boosts the antibody response. As the role of MPXV-neutralizing antibodies as a correlate of protection against disease and transmissibility is currently unclear, we conclude that cohort studies following vaccinated individuals are necessary to assess vaccine efficacy in at-risk populations.

Diminished amplification of SARS-CoV-2 ORF1ab in a commercial dual-target qRT-PCR diagnostic assay.

Here we describe a SARS-CoV-2 variant with diminished amplification of the ORF ORF1ab target in the Cobas® dual-target SARS-CoV-2 assay resulting in a discrepancy of Ct-values (Ct-value 20.7 for the E-gene and Ct-value 30.2 for ORF1ab). Five unique nucleotide mutations were identified in ORF1ab: C11450A (nsp10) C14178T (RdRp), G15006T (RdRp), G18394T (Hel), and G20995T (Hel). This case highlights the importance of surveillance of genomic regions used in molecular diagnostics and the importance of the public release of target regions used to update commercial and in-house developed SARS-CoV-2 PCR tests. This work underpins the importance of using dual-targets in molecular diagnostic assays to limit the change of false-negative results due to primer and/or probe mismatches.

Persistent Health Problems beyond Pulmonary Recovery up to 6 Months after Hospitalization for COVID-19: A Longitudinal Study of Respiratory, Physical, and Psychological Outcomes.

Rationale: Data on longitudinal recovery after hospitalization for coronavirus disease (COVID-19) currently remain scarce, just as outcomes beyond 3 months of follow-up do. Objectives: To evaluate the sequelae up to 6 months after hospitalization for COVID-19 by considering 1) recovery as it relates to pulmonary function, radiological abnormalities, physical and mental health status, and health-related quality of life (HR-QoL) and 2) the predictors of the most clinically relevant sequelae. Methods: Patients were evaluated at 6 weeks, 3 months, and 6 months after hospitalization by using pulmonary function testing, radiological evaluation, and online questionnaires on the physical and mental health status and HR-QoL. Outcomes were analyzed using repeated-measurement analyses. Results: Ninety-two patients were included (mean age, 58.2 ± 12.3 yr; 58 [63.0%] men). The estimated percentage of patients with impaired forced vital capacity improved from 25% at 6 weeks to 11% at 6 months; for impaired diffusion capacity, this percentage improved from 63% to 46%. Radiologically, ground-glass opacity decreased but fibrosis persisted. The majority of patients (89.1%) still reported one or more symptoms 6 months after discharge. Fatigue decreased significantly over time (P = 0.006). Nonetheless, fatigue remained in 51% of the patients at 6 months. HR-QoL (nearly) normalized in most domains at 6 months, except for physical role functioning, with persistent fatigue and the length of hospitalization being the most important predictors. Conclusions: During the first 6 months after hospitalization for COVID-19, most patients demonstrated continuing recovery across all health domains, but persistent sequelae were frequent. Fatigue was the most frequent residual and persistent symptom up to 6 months after hospitalization, importantly impacting HR-QoL.

The role of antibody indexes in clinical virology.

BACKGROUND: Serological techniques are an essential part of the diagnostic tools used in clinical virology. Among these techniques, antibody indexes are not novel, but do require specific expertise. Their niche has expanded substantially in recent years due to increasing evidence of their performance to diagnose viral infections. OBJECTIVES: This narrative review describes the background and clinical applications of antibody indexes. The first objective is to provide an overview of the theoretical background, insights for implementation, limitations and pitfalls. The second objective is to review the available evidence for the diagnostic performance, with a specific focus on viral encephalitis and uveitis. SOURCES: A comprehensive literature search was performed in PubMed, including original studies and reviews, with no time limit on the studies included. The following search terms were used: antibody index, Goldmann-Witmer coefficient, Reibergram, viral encephalitis, viral uveitis, herpes simplex virus, varicella zoster virus, cytomegalovirus, Epstein-Barr virus, rubella virus, measles virus, enterovirus, influenza virus, flaviviruses. CONTENT: Antibody indexes can support the diagnosis of a spectrum of viral infections in immune privileged sites such as the central nervous system and the eye, through the demonstration of virus-specific intrathecal or intraocular antibody production. This is especially useful in situations where PCR has a lower positivity rate: infections with rapid viral clearance due to natural immunity or treatment and chronic stages of viral infections. IMPLICATIONS: Antibody indexes expand the clinical microbiologist's diagnostic toolbox. Careful interpretation of the results of these assays is crucial and further standardization of methods is required to improve interchangeability of results between laboratories.

SARS-CoV-2 variants of concern partially escape humoral but not T-cell responses in COVID-19 convalescent donors and vaccinees.

The emergence of SARS-CoV-2 variants harboring mutations in the spike (S) protein has raised concern about potential immune escape. Here, we studied humoral and cellular immune responses to wild type SARS-CoV-2 and the B.1.1.7 and B.1.351 variants of concern in a cohort of 121 BNT162b2 mRNA-vaccinated health care workers (HCW). Twenty-three HCW recovered from mild COVID-19 disease and exhibited a recall response with high levels of SARS-CoV-2-specific functional antibodies and virus-specific T cells after a single vaccination. Specific immune responses were also detected in seronegative HCW after one vaccination, but a second dose was required to reach high levels of functional antibodies and cellular immune responses in all individuals. Vaccination-induced antibodies cross-neutralized the variants B.1.1.7 and B.1.351, but the neutralizing capacity and Fc-mediated functionality against B.1.351 was consistently 2- to 4-fold lower than to the homologous virus. In addition, peripheral blood mononuclear cells were stimulated with peptide pools spanning the mutated S regions of B.1.1.7 and B.1.351 to detect cross-reactivity of SARS-CoV-2-specific T cells with variants. Importantly, we observed no differences in CD4+ T-cell activation in response to variant antigens, indicating that the B.1.1.7 and B.1.351 S proteins do not escape T-cell-mediated immunity elicited by the wild type S protein. In conclusion, this study shows that some variants can partially escape humoral immunity induced by SARS-CoV-2 infection or BNT162b2 vaccination, but S-specific CD4+ T-cell activation is not affected by the mutations in the B.1.1.7 and B.1.351 variants.

Extent and Location of Tumor-Infiltrating Lymphocytes in Microsatellite-Stable Colon Cancer Predict Outcome to Adjuvant Active Specific Immunotherapy.

PURPOSE: To determine the prognostic and predictive value of tumor-infiltrating lymphocytes (TIL) in colon cancer in a cohort of patients who previously took part in a trial on adjuvant active specific immunotherapy (ASI). EXPERIMENTAL DESIGN: We determined the number and location of CD3 and CD8 positive T cells in archival tumor samples of 106 colon cancers. We correlated stromal and epithelial TIL numbers with tumor stage and treatment and determined the effects on disease-specific survival (DSS) and recurrence-free interval (RFI). RESULTS: On the basis of the data presented, we concluded that (i) high numbers of stromal CD3 T cells have positive prognostic value measured as DSS for patients with stage II microsatellite-stable tumors and (ii) high numbers of epithelial CD8-positive T cells have positive prognostic value measured as RFI for the group of patients with stage II microsatellite-stable tumors as well as for the whole group (so stage II plus stage III together). Furthermore, we concluded that high numbers of pre-existing stromal CD3-positive T cells are of positive predictive value in adjuvant ASI treatment measured as DSS as well as RFI. CONCLUSIONS: ASI therapy may contribute to an improved DSS and RFI in patients with microsatellite-stable colon tumors harboring high numbers of pre-existing stromal CD3(+) TIL. Validation in future clinical trials is awaited.