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result(s) for
"Lamers, Olivia A C"
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What motivates SARS-CoV-2 vaccine trial participants? A pre- and post-participation survey study
by
Hoogerwerf, Marie-Astrid
,
de Vries, Martine C.
,
Roestenberg, Meta
in
Adult
,
Aged
,
Biomedicine
2024
Background
Scientific advancement, including the testing and licensing of new drugs, relies heavily on clinical trials with healthy individuals. The motivations of clinical trial participants have been discussed intensively, as some worry that financial compensation may distract from the intrinsic risk of clinical research. Herein, we investigated the motivations and decisional factors influencing SARS-CoV-2 clinical trial participants. Moreover, since most surveys are administered after clinical trial participation, we were interested in whether the results were tainted by recall bias.
Methods
This was a cross-sectional observational study. Participants were administered a survey on two occasions, once before and once after participation in a clinical trial. The primary outcomes were the motivations and decisional factors of SARS-CoV-2 vaccine trial participants and the difference between the surveys collected before and after clinical trial participation.
Results
The survey response rate was 149/200 (75%). SARS-CoV-2 vaccine trial participants were mostly motivated by the desire to contribute to science and help others. Answers collected before and after the trial were not statistically different, indicating the absence of recall bias.
Conclusion
The decision-making process of clinical trial participants is complex and multi-faceted. Previous studies have shown that clinical trial participants have mixed motivations but never to the extent reported in the current survey. Here, we present a theoretical framework that attempts to explain how different motivational factors may contribute to decision forming.
Journal Article
Immunogenicity and reactogenicity of intradermal mRNA-1273 SARS-CoV-2 vaccination: a non-inferiority, randomized-controlled trial
by
Feltkamp, Mariet C. W.
,
Kuiper, Vincent P.
,
Roozen, Geert V. T.
in
692/308/2779/777
,
692/699/255/2514
,
Antibodies
2024
Fractional dosing can be a cost-effective vaccination strategy to accelerate individual and herd immunity in a pandemic. We assessed the immunogenicity and safety of primary intradermal (ID) vaccination, with a 1/5th dose compared with the standard intramuscular (IM) dose of mRNA-1273 in SARS-CoV-2 naïve persons. We conducted an open-label, non-inferiority, randomized controlled trial in the Netherlands between June and December 2021. One hundred and fifty healthy and SARS-CoV-2 naïve participants, aged 18–30 years, were randomized (1:1:1) to receive either two doses of 20 µg mRNA-1273 ID with a standard needle (SN) or the Bella-mu® needle (BM), or two doses of 100 µg IM, 28 days apart. The primary outcome was non-inferiority in seroconversion rates at day 43 (D43), defined as a neutralizing antibody concentration threshold of 465 IU/mL, the lowest response in the IM group. The non-inferiority margin was set at −15%. Neutralizing antibody concentrations at D43 were 1789 (95% CI: 1488–2150) in the IM and 1263 (951–1676) and 1295 (1020–1645) in the ID-SN and ID-BM groups, respectively. The absolute difference in seroconversion proportion between fractional and standard-dose groups was −13.95% (−24.31 to −3.60) for the ID-SN and −13.04% (−22.78 to −3.31) for the ID-BM group and exceeded the predefined non-inferiority margin. Although ID vaccination with 1/5th dose of mRNA-1273 did not meet the predefined non-inferior criteria, the neutralizing antibody concentrations in these groups are far above the proposed proxy for protection against severe disease (100 IU/mL), justifying this strategy in times of vaccine scarcity to accelerate mass protection against severe disease.
Journal Article
Treatment Strategies for GLILD in Common Variable Immunodeficiency: A Systematic Review
2021
Besides recurrent infections, a proportion of patients with Common Variable Immunodeficiency Disorders (CVID) may suffer from immune dysregulation such as granulomatous-lymphocytic interstitial lung disease (GLILD). The optimal treatment of this complication is currently unknown. Experienced-based expert opinions have been produced, but a systematic review of published treatment studies is lacking.
To summarize and synthesize the published literature on the efficacy of treatments for GLILD in CVID.
We performed a systematic review using the PRISMA guidelines. Papers describing treatment and outcomes in CVID patients with radiographic and/or histologic evidence of GLILD were included. Treatment regimens and outcomes of treatment were summarized.
6124 papers were identified and 42, reporting information about 233 patients in total, were included for review. These papers described case series or small, uncontrolled studies of monotherapy with glucocorticoids or other immunosuppressants, rituximab monotherapy or rituximab plus azathioprine, abatacept, or hematopoietic stem cell transplantation (HSCT). Treatment response rates varied widely. Cross-study comparisons were complicated because different treatment regimens, follow-up periods, and outcome measures were used. There was a trend towards more frequent GLILD relapses in patients treated with corticosteroid monotherapy when compared to rituximab-containing treatment regimens based on qualitative endpoints. HSCT is a promising alternative to pharmacological treatment of GLILD, because it has the potential to not only contain symptoms, but also to resolve the underlying pathology. However, mortality, especially among immunocompromised patients, is high.
We could not draw definitive conclusions regarding optimal pharmacological treatment for GLILD in CVID from the current literature since quantitative, well-controlled evidence was lacking. While HSCT might be considered a treatment option for GLILD in CVID, the risks related to the procedure are high. Our findings highlight the need for further research with uniform, objective and quantifiable endpoints. This should include international registries with standardized data collection including regular pulmonary function tests (with carbon monoxide-diffusion), uniform high-resolution chest CT radiographic scoring, and uniform treatment regimens, to facilitate comparison of treatment outcomes and ultimately randomized clinical trials.
Journal Article
Creation and preclinical evaluation of genetically attenuated malaria parasites arresting growth late in the liver
by
Kroeze, Hans
,
Geurten, Fiona J. A.
,
Roques, Magali
in
692/699
,
692/699/255/1629
,
Biomedical and Life Sciences
2022
Whole-sporozoite (WSp) malaria vaccines induce protective immune responses in animal malaria models and in humans. A recent clinical trial with a WSp vaccine comprising genetically attenuated parasites (GAP) which arrest growth early in the liver (PfSPZ-GA1), showed that GAPs can be safely administered to humans and immunogenicity is comparable to radiation-attenuated PfSPZ Vaccine. GAPs that arrest late in the liver stage (LA-GAP) have potential for increased potency as shown in rodent malaria models. Here we describe the generation of four putative
P. falciparum
LA-GAPs, generated by CRISPR/Cas9-mediated gene deletion. One out of four gene-deletion mutants produced sporozoites in sufficient numbers for further preclinical evaluation. This mutant,
Pf
Δ
mei2
, lacking the
mei2-like RNA
gene, showed late liver growth arrest in human liver-chimeric mice with human erythrocytes, absence of unwanted genetic alterations and sensitivity to antimalarial drugs. These features of
Pf
Δ
mei2
make it a promising vaccine candidate, supporting further clinical evaluation.
Pf
Δ
mei2
(GA2) has passed regulatory approval for safety and efficacy testing in humans based on the findings reported in this study.
Journal Article
Safety and Efficacy of Immunization with a Late-Liver-Stage Attenuated Malaria Parasite
2024
Efforts to develop a live-attenuated malaria vaccine are advancing. In this report, an engineered sporozoite-based vaccine is presented in a human challenge model, with associated immunologic assessments.
Journal Article
Single immunization with genetically attenuated Pf∆mei2 (GA2) parasites by mosquito bite in controlled human malaria infection: a placebo-controlled randomized trial
by
Kroeze, Hans
,
Tihaya, Mara S.
,
Franke-Fayard, Blandine M. D.
in
631/250/590/1867
,
692/699/255/1629
,
Adolescent
2025
Malaria vaccines consisting of metabolically active
Plasmodium falciparum
(
Pf
) sporozoites can offer improved protection compared with currently deployed subunit vaccines. In a previous study, we demonstrated the superior protective efficacy of a three-dose regimen of late-arresting genetically attenuated parasites administered by mosquito bite (GA2-MB) compared with early-arresting counterparts (GA1-MB) against a homologous controlled human malaria infection. Encouraged by these results, we explored the potency of a single GA2-MB immunization in a placebo-controlled randomized trial. Primary outcomes were safety and tolerability, time-to-parasitemia and protective efficacy. Humoral and cellular immunological results were considered secondary outcomes. Here we report the safe administration of GA2-MB with no breakthrough malaria and sterile protection in nine of ten participants at 6 weeks after a single immunization with 50 GA2-infected mosquitoes, compared with none of five mock-immunized participants, against a homologous controlled human malaria infection. Immunization increased circulating
Pf
-specific polyfunctional effector memory CD4
+
T cells coexpressing tumor necrosis factor and interleukin-2. This unprecedented 90% protective efficacy after a single low-dose immunization holds great promise for the potency of GA2 immunization. Future studies should demonstrate whether GA2 is similarly efficacious in pre-exposed populations and whether the favorable safety profile reported here holds up in larger groups. ClinicalTrials.gov registration:
NCT05468606
.
In a small randomized controlled clinical trial, a single immunization for malaria using mosquitoes infected with attenuated parasites showed unprecedented 90% protective efficacy and did not lead to breakthrough disease.
Journal Article
Causal chemoprophylactic activity of cabamiquine against Plasmodium falciparum in a controlled human malaria infection: a randomised, double-blind, placebo-controlled study in the Netherlands
by
van der Plas, Johan L
,
Lamers, Olivia A C
,
Bödding, Matthias
in
Antiparasitic agents
,
Blood
,
Case management
2023
Cabamiquine is a novel antimalarial that inhibits Plasmodium falciparum translation elongation factor 2. We investigated the causal chemoprophylactic activity and dose–exposure–response relationship of single oral doses of cabamiquine following the direct venous inoculation (DVI) of P falciparum sporozoites in malaria-naive, healthy volunteers.
This was a phase 1b, randomised, double-blind, placebo-controlled, adaptive, dose-finding, single-centre study performed in Leiden, Netherlands. Malaria-naive, healthy adults aged 18–45 years were divided into five cohorts and randomly assigned (3:1) to receive cabamiquine or placebo. Randomisation was done by an independent statistician using codes in a permuted block schedule with a block size of four. Participants, investigators, and study personnel were masked to treatment allocation. A single, oral dose regimen of cabamiquine (200, 100, 80, 60, or 30 mg) or matching placebo was administered either at 2 h (early liver-stage) or 96 h (late liver-stage) after DVI. The primary endpoints based on a per-protocol analysis set were the number of participants who developed parasitaemia within 28 days of DVI, time to parasitaemia, number of participants with documented parasite blood-stage growth, clinical symptoms of malaria, and exposure–efficacy modelling. The impact of cabamiquine on liver stages was evaluated indirectly by the appearance of parasitaemia in the blood. The Clopper–Pearson CI (nominal 95%) was used to express the protection rate. The secondary outcomes were safety and tolerability, assessed in those who had received DVI and were administered one dose of the study intervention. The trial was prospectively registered on ClinicalTrials.gov (NCT04250363).
Between Feb 17, 2020 and April 29, 2021, 39 healthy participants were enrolled (early liver-stage: 30 mg [n=3], 60 mg [n=6], 80 mg [n=6], 100 mg [n=3], 200 mg [n=3], pooled placebo [n=6]; late liver-stage: 60 mg [n=3], 100 mg [n=3], 200 mg [n=3], pooled placebo [n=3]). A dose-dependent causal chemoprophylactic effect was observed, with four (67%) of six participants in the 60 mg, five (83%) of six participants in the 80 mg, and all three participants in the 100 and 200 mg cabamiquine dose groups protected from parasitaemia up to study day 28, whereas all participants in the pooled placebo and 30 mg cabamiquine dose group developed parasitaemia. A single, oral dose of 100 mg cabamiquine or higher provided 100% protection against parasitaemia when administered during early or late liver-stage malaria. The median time to parasitaemia in those with early liver-stage malaria was prolonged to 15, 22, and 24 days for the 30, 60, and 80 mg dose of cabamiquine, respectively, compared with 10 days for the pooled placebo. All participants with positive parasitaemia showed documented blood-stage parasite growth, apart from one participant in the pooled placebo group and one participant in the 30 mg cabamiquine group. Most participants did not exhibit any malaria symptoms in both the early and late liver-stage groups, and those reported were mild in severity. A positive dose–exposure–efficacy relationship was established across exposure metrics. The median maximum concentration time was 1–6 h, with a secondary peak observed between 6 h and 12 h in all cabamiquine dose groups (early liver-stage). All cabamiquine doses were safe and well tolerated. Overall, 26 (96%) of 27 participants in the early liver-stage group and ten (83·3%) of 12 participants in the late liver-stage group reported at least one treatment-emergent adverse event (TEAE) with cabamiquine or placebo. Most TEAEs were of mild severity, transient, and resolved without sequelae. The most frequently reported cabamiquine-related TEAE was headache. No dose-related trends were observed in the incidence, severity, or causality of TEAEs.
The results from this study show that cabamiquine has a dose-dependent causal chemoprophylactic activity. Together with previously demonstrated activity against the blood stages combined with a half-life of more than 150 h, these results indicate that cabamiquine could be developed as a single-dose monthly regimen for malaria prevention.
The healthcare business of Merck KGaA, Darmstadt, Germany.
Journal Article
Opioid-related beliefs and prescription modalities for postoperative pain of Dutch and American physicians
2019
Opioid consumption and addiction are increasing worldwide, yet the USA stands out for its high addiction rates and opioid-related deaths. Considering that patient characteristics are comparable across western countries, physicians' prescribing modalities may influence opioid consumption. We conducted a pilot study to examine opioid-related beliefs and prescription habits of Dutch and American physicians.
A survey was administered to 488 physicians who routinely prescribe opioids for postoperative pain.
A total of 75 (16%) physicians responded to the survey. When deciding to prescribe opioids, Dutch physicians adopted a patient-guided approach, whereas most American doctors followed strict guidelines and protocols.
This study identified significant differences between Dutch and American physicians' attitudes and prescribing modalities.
Journal Article
Clinical tolerance but no protective efficacy in a placebo-controlled trial of repeated controlled schistosome infection
by
Yazdanbakhsh, Maria
,
Koopman, Jan Pieter R.
,
Brienen, Eric A.T.
in
Adolescent
,
Adult
,
Animals
2025
BACKGROUNDPartial protective immunity to schistosomiasis develops over time, following repeated praziquantel (PZQ) treatment. Moreover, animals develop protective immunity after repeated immunization with irradiated cercariae. Here, we evaluated the development of natural immunity through consecutive exposure-treatment cycles with Schistosoma mansoni in healthy, Schistosoma-naive participants using single-sex, controlled human S. mansoni infection.METHODSTwenty-four participants were randomized in a double-blinded (1:1) manner to either the reinfection group, which received 3 exposures (weeks 0, 9, and 18) to 20 male cercariae, or to the infection control group, which received 2 mock exposures with water (weeks 0 and 9) prior to cercariae exposure (week 18). Participants were treated with PZQ (or placebo) at weeks 8, 17, and 30. Attack rates (ARs) after the final exposure (weeks 19-30) using serum circulating anodic antigen (CAA) positivity were compared between groups. Adverse events (AEs) were collected for safety.RESULTSTwenty-three participants completed the follow-up. No protective efficacy was observed, given an 82% (9 of 11) AR after the final exposure in the reinfection group and 92% (11 of 12) in the infection control group (protective efficacy 11%; 95% CI -24% to 35%; P = 0.5). Related AEs were higher after the first infection (45%) compared with the second (27%) and third (28%) infections. Severe acute schistosomiasis was observed after the first infections only (2 of 12 in the reinfection group and 2 of 12 in the infection control group).CONCLUSIONRepeated Schistosoma exposure and treatment cycles resulted in apparent clinical tolerance, with fewer symptoms reported following subsequent infections, but did not result in protection against reinfection.TRIAL REGISTRATIONClinicalTrials.gov NCT05085470.FUNDINGEuropean Research Council (ERC) Starting Grant (no. 101075876).
Journal Article
Clinical tolerance but no protective efficacy in a placebo-controlled trial of repeated controlled schistosome infection
2025
BACKGROUND. Partial protective immunity to schistosomiasis develops over time, following repeated praziquantel (PZQ) treatment. Moreover, animals develop protective immunity after repeated immunization with irradiated cercariae. Here, we evaluated the development of natural immunity through consecutive exposure-treatment cycles with Schistosoma mansoni in healthy, Schistosoma-naive participants using single-sex, controlled human S. mansoni infection. METHODS. Twenty-four participants were randomized in a double-blinded (1:1) manner to either the reinfection group, which received 3 exposures (weeks 0, 9, and 18) to 20 male cercariae, or to the infection control group, which received 2 mock exposures with water (weeks 0 and 9) prior to cercariae exposure (week 18). Participants were treated with PZQ (or placebo) at weeks 8, 17, and 30. Attack rates (ARs) after the final exposure (weeks 19-30) using serum circulating anodic antigen (CAA) positivity were compared between groups. Adverse events (AEs) were collected for safety. RESULTS. Twenty-three participants completed the follow-up. No protective efficacy was observed, given an 82% (9 of 11) AR after the final exposure in the reinfection group and 92% (11 of 12) in the infection control group (protective efficacy 11%; 95% Cl -24% to 35%; P = 0.5). Related AEs were higher after the first infection (45%) compared with the second (27%) and third (28%) infections. Severe acute schistosomiasis was observed after the first infections only (2 of 12 in the reinfection group and 2 of 12 in the infection control group). CONCLUSION. Repeated Schistosoma exposure and treatment cycles resulted in apparent clinical tolerance, with fewer symptoms reported following subsequent infections, but did not result in protection against reinfection. TRIAL REGISTRATION. ClinicalTrials.gov NCT05085470. FUNDING. European Research Council (ERC) Starting Grant (no. 101075876).
Journal Article