Publications by authors named "Katrin Dubischar"

Background: Chikungunya disease, caused by chikungunya virus (CHIKV), is associated with substantial morbidity, including debilitating CHIKV-related arthralgia.

Methods: Three clinical trials of a CHIKV vaccine (VLA1553, IXCHIQ®) were conducted in the USA: a Phase 1 dose-finding trial, a pivotal Phase 3 trial and a Phase 3 lot-to-lot consistency trial. Participants were healthy adults (≥18 years) and received a single intramuscular dose of VLA1553 (3520 participants) or placebo (1033 participants).

View Article and Find Full Text PDF

Background: Over the past 20 years, over 5 million cases of chikungunya, a mosquito-transmitted viral disease, have been reported in over 110 countries. Until recently, preventative strategies for chikungunya were largely ineffective, relying on vector control and individual avoidance of mosquito bites.

Methods: This review outlines the preclinical and clinical efficacy and safety data that led to the approval of VLA1553 (IXCHIQ®), a live-attenuated vaccine against chikungunya disease.

View Article and Find Full Text PDF

Background: Chikungunya outbreaks have been reported in Brazil since 2014. Adolescents are a sensitive population who would benefit from a prophylactic vaccine. This study assessed the immunogenicity and safety of the vaccine VLA1553 in adolescents in Brazil.

View Article and Find Full Text PDF
Article Synopsis
  • The recently licensed chikungunya vaccine, IXCHIQ, shows strong cross-neutralizing antibody responses against chikungunya virus and several related alphaviruses.
  • The study measured antibody responses at one month, six months, and one year post-vaccination, revealing 100% seroconversion to most viruses tested, except for Ross River virus at 83.3%.
  • IXCHIQ appears to provide antibody responses similar to natural chikungunya infections, suggesting it may offer protection to populations at risk from multiple alphavirus infections in areas where the vaccine is deployed.
View Article and Find Full Text PDF

Background: Chikungunya virus infection can lead to long-term debilitating symptoms. A precursor phase 3 clinical study showed high seroprotection (defined as a 50% plaque reduction of chikungunya virus-specific neutralising antibodies on a micro plaque reduction neutralisation test [μPRNT] titre of ≥150 in baseline seronegative participants) up to 6 months after a single vaccination of the chikungunya virus vaccine VLA1553 (Valneva Austria, Vienna, Austria) and a good safety profile. Here we report antibody persistence and safety up to 2 years.

View Article and Find Full Text PDF
Article Synopsis
  • - The study evaluated the safety and effectiveness of a booster dose of VLA15, an investigational Lyme disease vaccine, after previously completing the primary vaccination series, as Lyme borreliosis cases are on the rise and effective vaccines are lacking.
  • - Conducted as a randomized, placebo-controlled trial, the research involved healthy adults aged 18-65 from five US centers, who received either 135 μg or 180 μg of VLA15 or placebo over an 18-month period before the booster was administered.
  • - Results focused on assessing the booster dose's immunogenicity and safety, with monitoring conducted by impartial groups to ensure accurate data collection, and the study is registered and completed under ClinicalTrials.gov (NCT
View Article and Find Full Text PDF

Background: Chikungunya is a serious and debilitating viral infection with a significant disease burden. VLA1553 (IXCHIQ®) is a live-attenuated vaccine licensed for active immunization for prevention of disease caused by chikungunya virus (CHIKV).

Methods: Immunogenicity following a single dose of VLA1553 was evaluated in healthy adults aged ≥18 years in two Phase 3 trials [N = 656 participants (per protocol analysis set)].

View Article and Find Full Text PDF
Article Synopsis
  • A new preventive vaccine for Lyme borreliosis, VLA15, targeting key Borrelia outer surface proteins, is being studied due to rising infection rates and the challenges in timely diagnosis and treatment.
  • Two phase 2 clinical trials were conducted on healthy adults to determine the optimal vaccine dosage and schedule, with participants receiving varying dosages (90 μg, 135 μg, or 180 μg) via injections.
  • The primary goal of the studies was to measure the vaccine's effectiveness based on the levels of specific antibodies (IgG) one month after the final dose, ensuring rigorous safety and randomization protocols throughout the trials.
View Article and Find Full Text PDF

Background: The global spread of the chikungunya virus (CHIKV) increases the exposure risk for individuals travelling to or living in endemic areas. This Phase 3 study was designed to demonstrate manufacturing consistency between three lots of the single shot live-attenuated CHIKV vaccine VLA1553, and to confirm the promising immunogenicity and safety data obtained in previous trials.

Methods: This randomized, double-blinded, lot-to-lot consistency, Phase 3 study, assessed immunogenicity and safety of VLA1553 in 408 healthy adults (18-45 years) in 12 sites across the USA.

View Article and Find Full Text PDF

Background: Lyme borreliosis, potentially associated with serious long-term complications, is caused by the species complex Borrelia burgdorferi sensu lato. We investigated a novel Lyme borreliosis vaccine candidate (VLA15) targeting the six most common outer surface protein A (OspA) serotypes 1-6 to prevent infection with pathogenic Borrelia spp prevalent in Europe and North America.

Methods: This was a partially randomised, observer-masked, phase 1 study in healthy adults older than 18 years to younger than 40 years (n=179) done in trial sites in Belgium and the USA.

View Article and Find Full Text PDF

Objectives: Booster doses for COVID-19 vaccinations have been shown to amplify the waning immune response after primary vaccination and to enhance protection against emerging variants of concern (VoCs). Here, we aimed to assess the immunogenicity and safety of a booster dose of an inactivated whole-virus COVID-19 vaccine (VLA2001) after primary vaccination with 2 doses of either VLA2001 or ChAdOx1-S (Oxford-Astra Zeneca), including the cross-neutralization capacity against the Delta and Omicron VoCs.

Methods: This interim analysis of an open-label extension of a randomized, controlled phase 3 trial assessed a single booster dose of an inactivated whole-virus COVID-19 vaccine (VLA2001) in healthy or medically stable adults aged 18 years and above, recruited in 21 clinical sites in the UK, who had previously received two doses of either VLA2001 or ChAdOx1-S.

View Article and Find Full Text PDF

Background: VLA1553 is a live-attenuated vaccine candidate for active immunisation and prevention of disease caused by chikungunya virus. We report safety and immunogenicity data up to day 180 after vaccination with VLA1553.

Methods: This double-blind, multicentre, randomised, phase 3 trial was done in 43 professional vaccine trial sites in the USA.

View Article and Find Full Text PDF

Background: Zika virus (ZIKV) is an emerging public health threat, rendering development of a safe and effective vaccine against the virus a high priority to face this unmet medical need. Our vaccine candidate has been developed on the same platform used for the licensed vaccine IXIARO®, a vaccine against Japanese Encephalitis virus, another closely related member of the Flaviviridae family.

Methods: Between 24 February 2018 and 16 November 2018, we conducted a randomized, observer-blinded, placebo controlled, single center phase 1 study to assess the safety and immunogenicity of an adjuvanted, inactivated, purified whole-virus Zika vaccine candidate in the USA.

View Article and Find Full Text PDF

Background: The Valneva COVID-19 vaccine (VLA2001; Valneva Austria, Vienna, Austria) is an inactivated whole-virus, adjuvanted SARS-CoV-2 vaccine. We aimed to assess the safety and immunogenicity of primary vaccination with VLA2001 versus the ChAdOx1-S (Oxford-AstraZeneca) adenoviral-vectored vaccine.

Methods: In this immunobridging phase 3 trial (COV-COMPARE), participants aged 18 years and older who were medically stable (as determined by an investigator) were enrolled at 26 sites in the UK.

View Article and Find Full Text PDF

Objectives: We aimed to evaluate the safety and optimal dose of a novel inactivated whole-virus adjuvanted vaccine against SARS-CoV-2: VLA2001.

Methods: We conducted an open-label, dose-escalation study followed by a double-blind randomized trial using low, medium and high doses of VLA2001 (1:1:1). The primary safety outcome was the frequency and severity of solicited local and systemic reactions within 7 days after vaccination.

View Article and Find Full Text PDF

Background: Chikungunya disease, which results in incapacitating arthralgia, has been reported worldwide. We developed a live-attenuated chikungunya virus (CHIKV) vaccine candidate designed for active immunisation of the general population living in endemic regions, as well as serving as a prophylactic measure for travellers to endemic areas.

Methods: This single-blind, randomised, dose-escalation, phase 1 study investigated as primary outcome safety of a live-attenuated CHIKV vaccine candidate.

View Article and Find Full Text PDF

Background: In an initial study among children from non-Japanese encephalitis (JE)-endemic countries, seroprotection rates remained high 6 months after completion of the primary series with IXIARO®.

Methods: In this open-label follow-up study, a subset of 23 children who received a 2-dose primary series of IXIARO® in the parent study, were evaluated for safety and neutralizing antibody persistence for 36 months.

Results: Seroprotection rates (SPRs) remained high but declined from 100% one month after primary immunization to 91.

View Article and Find Full Text PDF

Background: Pseudomonas aeruginosa infections are a serious threat in intensive care units (ICUs). The aim of this confirmatory, randomized, multicenter, placebo-controlled, double-blind, phase 2/3 study was to assess the efficacy, immunogenicity, and safety of IC43 recombinant Pseudomonas aeruginosa vaccine in non-surgical ICU patients.

Methods: Eight hundred patients aged 18 to 80 years admitted to the ICU with expected need for mechanical ventilation for ≥ 48 h were randomized 1:1 to either IC43 100 μg or saline placebo, given in two vaccinations 7 days apart.

View Article and Find Full Text PDF

Immunization with the Japanese encephalitis (JE) vaccine IXIARO® results in protective neutralizing antibody levels for one year. Since persistence of protective titer levels beyond one year was unknown, a 5 years follow-up study was conducted. Additionally, data were stratified to compare the persistence of protective neutralizing antibodies against JE in people with or without tick-borne encephalitis (TBE) vaccination.

View Article and Find Full Text PDF

Background: An inactivated Vero cell culture derived Japanese encephalitis virus vaccine (IXIARO) requires a booster dose 1 year after primary schedule for long-term antibody persistence in adults. The aim of this study is to evaluate immunogenicity and safety of a booster dose in children 2 months to <18 years of age.

Methods: This is a randomized, controlled open-label study in the Philippines.

View Article and Find Full Text PDF
Article Synopsis
  • Japanese encephalitis is a significant health issue in Asia, particularly impacting young travelers, prompting a study on the safety of the IXIARO vaccine in children.
  • A total of 1869 children aged 2 months to 17 years were randomized to receive IXIARO or control vaccines, with adverse events monitored for 56 days and up to 7 months post-vaccination.
  • The results indicated that the incidence of adverse events was similar across all groups, with the most common side effects being fever, which decreased with age but showed no significant differences between the IXIARO and control vaccines.
View Article and Find Full Text PDF
Article Synopsis
  • Japanese encephalitis (JE) is a serious health risk in Asia and has no pediatric vaccine available in Europe and the U.S., posing a risk to young travelers.
  • A study involved children aged 2 months to 17 years receiving two doses of the IXIARO vaccine, showing over 99% achieved seroconversion and strong antibody responses, especially in younger children.
  • The vaccine demonstrated high effectiveness, maintaining protective antibody levels for up to seven months post-vaccination, regardless of previous immunity to JE or dengue viruses.
View Article and Find Full Text PDF

Background: IXIARO® is a Vero cell-derived, inactivated Japanese encephalitis (JE) vaccine licensed mainly in western countries for children and adults traveling to JE endemic areas. Limited immunogenicity and safety data in elderly travelers have been available.

Objectives: To evaluate safety and immunogenicity of IXIARO in elderly subjects.

View Article and Find Full Text PDF

Background: Clostridium difficile infection (CDI) is the leading cause of antibiotic-associated diarrhoea and colitis and the most common pathogen of health care-associated infections. In the US, CDI causes approximately half a million infections and close to 30,000 deaths. Despite antibiotic treatment of C.

View Article and Find Full Text PDF