Assessment of hybrid population immunity to SARS-CoV-2 following breakthrough infections of distinct SARS-CoV-2 variants by the detection of antibodies to nucleoprotein.

Immunity induced by vaccination and infection, referred to as hybrid immunity, provides better protection against SARS-CoV-2 infections compared to immunity induced by vaccinations alone. To assess the development of hybrid immunity we investigated the induction of Nucleoprotein-specific antibodies in PCR-confirmed infections by Delta or Omicron in vaccinated individuals (n = 520). Eighty-two percent of the participants with a breakthrough infection reached N-seropositivity.

Epidemiology of Pathogens Listed as Potential Bioterrorism Agents, the Netherlands, 2009‒2019.

We provide incidences (cases/10 million persons) in the Netherlands during 2009-2019 for pathogens listed as potential bioterrorism agents. We included pathogens from the highest categories of the European Medicines Agency or the US Centers for Disease Control and Prevention. Notifiable diseases and recently published data were used to calculate the average annual incidence.

Mpox outbreak in the Netherlands, 2022: public health response, characteristics of the first 1,000 cases and protection of the first-generation smallpox vaccine.

In early May 2022, a global outbreak of mpox started among persons without travel history to regions known to be enzootic for monkeypox virus (MPXV). On 8 August 2022, the Netherlands reported its 1,000th mpox case, representing a cumulative incidence of 55 per million population, one of the highest cumulative incidences worldwide. We describe characteristics of the first 1,000 mpox cases in the Netherlands, reported between 20 May and 8 August 2022, within the context of the public health response.

Performance of Zika Assays in the Context of Toxoplasma gondii, Parvovirus B19, Rubella Virus, and Cytomegalovirus (TORCH) Diagnostic Assays.

Infections during pregnancy that may cause congenital abnormalities have been recognized for decades, but their diagnosis is challenging. This was again illustrated with the emergence of Zika virus (ZIKV), highlighting the inherent difficulties in estimating the extent of pre- and postnatal ZIKV complications because of the difficulties in establishing definitive diagnoses. We reviewed the epidemiology, infection kinetics, and diagnostic methods used for , parvovirus B19, rubella virus, and cytomegalovirus (TORCH) infections and compared the results with current knowledge of ZIKV diagnostic assays to provide a basis for the inclusion of ZIKV in the TORCH complex evaluations.

Oral fluid: Non-invasive alternative for parvovirus B19 diagnosis?

Background: Infections with parvovirus B19 (B19V) have been associated with a wide range of disease manifestations of which erythema infectiosum (fifth disease) in children is most common. Clinical signs following infection of children with B19V can be similar to measles and rubella. Laboratory detection of B19V infections is based on detection of B19V-specific IgM antibodies by enzyme immunoassay (IgM-EIA) and/or B19V DNA by quantitative PCR (qPCR) on blood samples.

Case of seasonal reassortant A(H1N2) influenza virus infection, the Netherlands, March 2018.

A seasonal reassortant A(H1N2) influenza virus harbouring genome segments from seasonal influenza viruses A(H1N1)pdm09 (HA and NS) and A(H3N2) (PB2, PB1, PA, NP, NA and M) was identified in March 2018 in a 19-months-old patient with influenza-like illness (ILI) who presented to a general practitioner participating in the routine sentinel surveillance of ILI in the Netherlands. The patient recovered fully. Further epidemiological and virological investigation did not reveal additional cases.

A review of the changes to the licensing of influenza vaccines in Europe.

In 2014, the European Committee for Medicinal Products for Human Use (CHMP) published a draft regulatory guideline for the evaluation of influenza vaccines. Following a public consultation round, the final guidance will be published in the near future. Here, we highlight the main changes in the clinical section in this guideline and discuss the background to these changes and whether the new consolidated guidance document can be expected to achieve a better understanding of the performance of seasonal, zoonotic and pandemic influenza vaccines during the regulatory licensing process.

Effectiveness of MF59™ adjuvanted influenza A(H1N1)pdm09 vaccine in risk groups in the Netherlands.

Background: The aim of the present study was to estimate the effectiveness of the MF59™-adjuvanted influenza A(H1N1)pdm09 vaccine against medically attended influenza-like illness and RT-PCR confirmed influenza in the at-risk population and persons over 60 in the Netherlands.

Methods: We conducted a retrospective cohort study in a Dutch based GP medical record database between 30 November 2009 and 1 March 2010 to estimate the vaccine effectiveness against influenza-like illness. Within the cohort we nested a test negative case-control study to estimate the effectiveness against laboratory confirmed influenza.

Annual incidence rate of schizophrenia and schizophrenia spectrum disorders in a longitudinal population-based cohort study.

Background: Longitudinal incidence studies of schizophrenia spectrum disorders (SSD) performed in mental health service organizations are prone to confounding factors not found in research performed in the general population.

Objectives: To estimate the incidence rates (IRs) over a 10-year period of SSD (broadly defined) and schizophrenia (narrowly defined) in the general population and to analyze associated risk factors.

Methods: A cohort study (1996-2006) in a large general practitioners research database was conducted with longitudinal medical records of 350,524 patients throughout the Netherlands.

Characteristics of orphan drug applications that fail to achieve marketing approval in the USA.

The US Orphan Drug Act has fostered the development of drugs for patients with rare diseases by granting 'orphan designations', although several orphan drugs for which a marketing application has been submitted to the FDA have failed to obtain approval. This study identified the clinical trial design, the level of experience of the sponsor and the level of interaction with the FDA to be associated with non-approval. Sponsors, therefore, should engage in dialogue with the FDA and thoughtfully design pivotal clinical trials in accordance with FDA guidance documents.

Annual influenza vaccination in community-dwelling elderly individuals and the risk of lower respiratory tract infections or pneumonia.

Background: Influenza vaccination has been associated with a reduction in the number of hospitalizations for respiratory conditions in elderly persons over the period from 1996 to 2002. Little is known, however, about the effect of influenza vaccination on the whole range of severity of respiratory tract infections.

Methods: We investigated the effect of annual influenza vaccination on the occurrence of lower respiratory tract infections (LRTIs) in community-dwelling elderly individuals.

Influenza vaccination in community-dwelling elderly: impact on mortality and influenza-associated morbidity.

Background: Influenza-related morbidity and mortality have been extensively studied with hospital and reimbursement data. However, little is known about the effectiveness of the annual vaccination programs in generally healthy community-dwelling elderly. The objective of our study was to investigate the effectiveness of influenza vaccination in community-dwelling elderly during the 1996 to 1997 influenza epidemic.