Publications by authors named "Boxmeer J"

Background: We previously showed that ARCT-154, a self-amplifying mRNA COVID-19 vaccine, had improved immunogenicity and antibody persistence compared with conventional mRNA or adenovirus vector vaccines. In this study, we compared ARCT-2301, a bivalent self-amplifying mRNA vaccine (Asp614Gly and omicron BA.4/5 variant), with the bivalent Comirnaty omicron BA.

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: Self-amplifying mRNA vaccines have the potential to increase the magnitude and duration of protection against COVID-19 by boosting neutralizing antibody titers and cellular responses. : In this study, we used the immunogenicity data from a phase 3 randomized trial comparing the immunogenicity of ARCT-154, a self-amplifying mRNA COVID-19 vaccine, with BNT162b2 mRNA COVID-19 vaccine to estimate the relative vaccine efficacy (rVE) of the two vaccines over time in younger (<60 years) and older (≥60 years) adults. : By day 181 post-vaccination, the rVE against symptomatic and severe Wuhan-Hu-1 disease was 9.

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Study Question: Does offering the Pleasure&Pregnancy (P&P) programme rather than expectant management improve naturally conceived ongoing pregnancy rates in couples diagnosed with unexplained infertility?

Summary Answer: The P&P programme had no effect on the ongoing pregnancy rates of couples with unexplained infertility.

What Is Known Already: Underpowered studies suggested that face-to-face interventions targeting sexual health may increase pregnancy rates. The impact of an eHealth sexual health programme had yet to be evaluated by a large randomized controlled trial.

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Objective: To evaluate pregnancy and infant outcomes among persons immunized with a cell-based quadrivalent inactivated influenza vaccine (IIV4c) during routine pregnancy care. Design: Prospective observational cohort. Setting: US-based obstetrics/gynecology clinics.

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This US-based, prospective observational cohort study evaluated the safety of a quadrivalent inactivated influenza vaccine (IIV4; Afluria Quadrivalent) in pregnant persons immunized over four influenza seasons between 2017 and 2021. Pregnancy outcomes included live birth, stillbirth, spontaneous abortion, and elective termination. Infant events of interest were major congenital malformations (MCMs), preterm birth (<37 weeks gestational age), and low birth weight (LBW).

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Study Question: Is a single endometrial scratch prior to the second fresh IVF/ICSI treatment cost-effective compared to no scratch, when evaluated over a 12-month follow-up period?

Summary Answer: The incremental cost-effectiveness ratio (ICER) for an endometrial scratch was €6524 per additional live birth, but due to uncertainty regarding the increase in live birth rate this has to be interpreted with caution.

What Is Known Already: Endometrial scratching is thought to improve the chances of success in couples with previously failed embryo implantation in IVF/ICSI treatment. It has been widely implemented in daily practice, despite the lack of conclusive evidence of its effectiveness and without investigating whether scratching allows for a cost-effective method to reduce the number of IVF/ICSI cycles needed to achieve a live birth.

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Study Question: Does endometrial scratching in women with one failed IVF/ICSI treatment affect the chance of a live birth of the subsequent fresh IVF/ICSI cycle?

Summary Answer: In this study, 4.6% more live births were observed in the scratch group, with a likely certainty range between -0.7% and +9.

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Suboptimal vaccine effectiveness against seasonal influenza is a significant public health concern, partly explained by antigenic differences between vaccine viruses and viruses circulating in the environment. Haemagglutinin mutations within vaccine viruses acquired during serial passage in eggs have been identified as a source of antigenic variation between vaccine and circulating viruses. This study retrospectively compared the antigenic similarity of circulating influenza isolates with egg- and cell-propagated reference viruses to assess any observable trends over a 16-year period.

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Background: Success rates of assisted reproductive techniques (ART) are approximately 30%, with the most important limiting factor being embryo implantation. Mechanical endometrial injury, also called 'scratching', has been proposed to positively affect the chance of implantation after embryo transfer, but the currently available evidence is not yet conclusive. The primary aim of this study is to determine the effect of endometrial scratching prior to a second fresh in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycle on live birth rates in women with a failed first IVF/ICSI cycle.

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Because of changes in the society, couples in Western countries are increasingly delaying reproduction. This is accompanied by unhealthy lifestyles that may be detrimental not only to general health but also to reproductive capacity. It is well known that maternal age has detrimental effects on fertility; the paternal influence on this outcome is largely unknown.

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Background: Maternal hyperhomocysteinemia is detrimental for reproduction, but the effects on embryo quality are unknown. The aim of this study was to investigate whether biomarkers of the homocysteine pathway are associated with in vitro fertilization (IVF) outcome.

Methods: In a prospective study, we investigated biomarkers of the homocysteine pathway for associations with embryo quality and biochemical pregnancy in women undergoing IVF or intracytoplasmic sperm injection treatment (n = 181).

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Objective: To determine associations between vitamin B status, homocysteine (tHcy), semen parameters, and sperm DNA damage.

Design: Observational study.

Setting: A tertiary referral fertility clinic.

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Background: Ovarian stimulation gives rise to supraphysiological estradiol levels, which may affect oocyte quality. This study aims to investigate whether ovarian stimulation deranges the homocysteine pathway thereby affecting the pre-ovulatory follicle.

Methods: Blood samples were collected on cycle day 2 and the day of hCG administration in 181 women undergoing ovarian stimulation for IVF.

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Objective: To investigate the influence of folic acid supplementation on the follicular fluid concentrations of folate and total homocysteine and their relationship to the diameter of the follicle.

Design: Observational study.

Setting: Tertiary referral fertility clinic at the Erasmus MC, University Medical Center, Rotterdam, The Netherlands.

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Mild hyperhomocysteinemia is caused by B vitamin deficiencies. We hypothesize that these biochemical derangements detrimentally affect spermatogenesis. Therefore, the aim of this study was to investigate the folate, cobalamin, pyridoxine, and homocysteine concentrations in blood and seminal plasma and the associations between these biomarkers and semen parameters in men participating in an in vitro fertilization or intracytoplasmic sperm injection program.

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Two primigravidae, 33 and 30 years of age, were admitted for pre-eclampsia after 41 and 32 weeks ofamenorrhoea, respectively. Both complained of dyspnoea that turned out to be due to heart failure. The foetuses both died before birth, but the women recovered following intensive care.

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