| 1. |
- Erra, Elina O, et al.
(författare)
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A single dose of vero cell-derived Japanese encephalitis (JE) vaccine (Ixiaro) effectively boosts immunity in travelers primed with mouse brain-derived JE vaccines
- 2012
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press (OUP). - 1058-4838 .- 1537-6591. ; 55:6, s. 825-834
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:A significant part of the world population lives in areas with endemic Japanese encephalitis (JE). For travelers from nonendemic countries, Vero cell-derived vaccine (JE-VC; Ixiaro) has replaced traditional mouse brain-derived vaccines (JE-MB) associated with safety concerns. The 2 vaccines are derived from different viral strains: JE-VC from the SA14-14-2 strain and JE-MB from the Nakayama strain. No data exist regarding whether JE-VC can be used to boost immunity after a primary series of JE-MB; therefore, a primary series of JE-VC has been recommended to all travelers regardless of previous vaccination history.METHODS:One hundred twenty travelers were divided into 4 groups: Volunteers with no prior JE vaccination received primary immunization with (group 1) JE-MB or (group 2) JE-VC, and those primed with JE-MB received a single booster dose of (group 3) JE-MB or (group 4) JE-VC. Immune responses were tested before and 4-8 weeks after vaccination using plaque reduction neutralization test (PRNT) against both vaccine strains.RESULTS:In vaccine-naive travelers, the vaccination response rate for test strains Nakayama and SA14-14-2 was 100% and 87% after primary vaccination with JE-MB and 87% and 94% after JE-VC, respectively. Antibody levels depended on the target virus, with higher titers against homologous than heterologous PRNT(50) target strain (P < .001). In travelers primed with JE-MB, vaccination response rates were 91% and 91%, and 98% and 95% after a booster dose of JE-MB or JE-VC, respectively. Subgroup analysis revealed that a higher proportion of primed (98%/95%) than nonprimed (39%/42%) volunteers responded to a single dose of JE-VC (P < .001).CONCLUSIONS:A single dose of JE-VC effectively boosted immunity in JE-MB-primed travelers. Current recommendations should be reevaluated.CLINICAL TRIALS REGISTRATION:NCT01386827.
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| 2. |
- Erra, Elina O., et al.
(författare)
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Cross-protection elicited by primary and booster vaccinations against Japanese encephalitis : A two-year follow-up study
- 2013
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 32:1, s. 119-123
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Tidskriftsartikel (refereegranskat)abstract
- Background: The inactivated Vero cell-derived vaccine (JE-VC, IXIARO) has replaced the traditional mouse brain-derived preparations (JE-MB) in travelers' vaccinations against Japanese encephalitis. We showed recently that a single JE-VC dose efficiently boosts immunity in JE-MB-primed vaccinees, and that JE-VC elicits cross-protective immunity against non-vaccine genotypes, including the emerging genotype I. While these studies only provided short-term data, the present investigation evaluates the longevity of seroprotection in the same volunteers.Methods:The study comprised 48 travelers who had received (1) JE-VC primary series, (2) JE-MB primary series followed by a single JE-VC booster dose, or (3) JE-MB primary series and a single JE-MB booster dose. Serum samples were collected two years after the last vaccine dose, and evaluated with the plaque-reduction neutralization test against seven Japanese encephalitis virus strains representing genotypes I-IV. PRNT50 titers >= 10 were considered protective.Results:Two years after the primary series with JE-VC, 87-93% of the vaccinees proved to be cross-protected against test strains representing genotypes II-IV and 73% against those of genotype I. After a single homologous or heterologous booster dose to JE-MB-primed subjects, the two-year seroprotection rates against genotype I-IV strains were 89-100%.Conclusions:After JE-VC primary series, seroprotection appeared to wane first against genotype I. The first booster should not be delayed beyond two years. In JE-MB-primed subjects, a single JE-VC booster provided cross-protective immunity against genotype I-IV strains in almost all vaccinees, suggesting an interval of two years or even longer for the second booster. These data further support the use of a single JE-VC dose for boosting JE-MB immunity.
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| 3. |
- Erra, Elina O, et al.
(författare)
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Cross-protective capacity of Japanese encephalitis (JE) vaccines against circulating heterologous JE virus genotypes
- 2013
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press (OUP). - 1058-4838 .- 1537-6591. ; 56:2, s. 267-270
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Tidskriftsartikel (refereegranskat)abstract
- Current Japanese encephalitis vaccines are derived from strains of genotype III, yet heterologous genotypes are emerging in endemic areas. Inactivated vaccines given to European travelers were found to elicit protective levels of neutralizing antibodies against heterologous strains of genotypes I-IV.
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| 4. |
- Kantele, Anu, et al.
(författare)
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Three-dose versus four-dose primary schedules for tick-borne encephalitis (TBE) vaccine FSME-immun for those aged 50 years or older : A single-centre, open-label, randomized controlled trial
- 2022
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Ingår i: Vaccine. - : Elsevier. - 0264-410X .- 1873-2518. ; 40:9, s. 1299-1305
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Tidskriftsartikel (refereegranskat)abstract
- Background: TBE vaccination failures among those past middle age have raised concern about immune response declining with age. We investigated immunogenicity of the TBE-vaccine FSME-Immun among those aged 50+ years using the standard three-dose primary series and alternative four-dose schedules. Methods: In this single-centre, open-label, randomized controlled trial, 200 TBE-naive Swedish adults were given primary TBE vaccination with FSME-Immun. Those aged 50+ years (n = 150) were randomized to receive the standard three-dose (days 0-30-360) or one of two four-dose series (0-7-21-360; 0-30- 90-360). For participants < 50 years (n = 50) the standard three-dose schedule was used. Titres of neu-tralizing antibodies were determined on days 0, 60, 120, 360, and 400. The main outcome was the log titre of TBE virus-specific neutralizing antibodies on day 400. Results: The three-dose schedule yielded lower antibody titres among those aged 50+ years than the younger participants on day 400 (geometric mean titre 41 versus 74, p < 0.05). The older group showed higher titres for the four-dose 0-7-21-360 than the standard three-dose schedule both on day 400 (103 versus 41, p < 0.01; primary end point) and at the other testing points (days 60,120, 360). Using the other four-dose schedule (0-30-90-360), no such difference was observed on day 400 (63 versus 41, NS). Conclusion: Immune response to the TBE vaccine declined with age. A four-dose schedule (0-7-21-360) may benefit those aged 50 years or older. This study is registered at ClinicalTrials.gov, NCT01361776. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).
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| 5. |
- Stefansson, Måns, et al.
(författare)
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Safety and tolerability of frozen, capsulized autologous faecal microbiota transplantation. A randomized double blinded phase I clinical trial
- 2023
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 18:9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Faecal microbiota transplantation (FMT) is recommended treatment for recurrent Clostridioides difficile infection and is studied as a potential modifier of other gastrointestinal and systemic disorders. Autologous FMT limits the potential risks of donor transplant material and enables prophylactic treatment. Capsulized FMT is convenient and accessible, but safety data are lacking.Aims: To describe safety and tolerability of capsules containing autologous FMT, compared to placebo, in healthy volunteers treated with antibiotics.Method: Healthy volunteers without antibiotic exposure during the past three months, that had a negative Clostridioides difficile stool sample, were recruited. Study persons donated faeces for production of capsules containing autologous microbiota. They were then given Clindamycin for seven days to disrupt the intestinal microbiota, which was followed by a two-day washout. Study persons were then randomized (1:1) to unsupervised treatment with autologous faecal matter or placebo, with two capsules twice daily for five days. A standardized questionnaire about side effects and tolerability, daily until day 28, and on days 60 and 180, was completed.Results: Twenty-four study persons were included, all completed the treatment. One person from the placebo and FMT groups each, were lost to follow up from days 21 and 60, respectively. No study person experienced serious side effects, but severe fatigue was reported during the antibiotic period (n = 2). Reported side effects were mild to moderate and there were no significant differences between the groups. Reported general and intestinal health improved significantly and similarly in both groups after the antibiotic treatment. Time to normalized intestinal habits were 17 and 19 days from study start in the placebo group and the FMT group, respectively (p = 0.8).Conclusion: Capsulized frozen autologous faecal microbiota transplantation was safe and well tolerated but did not affect time to normalized intestinal habits compared to placebo.
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| 6. |
- Varnaite, Renata, et al.
(författare)
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Magnitude and Functional Profile of the Human CD4(+) T Cell Response throughout Primary Immunization with Tick-Borne Encephalitis Virus Vaccine
- 2020
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Ingår i: Journal of Immunology. - : AMER ASSOC IMMUNOLOGISTS. - 0022-1767 .- 1550-6606. ; 204:4, s. 914-922
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Tidskriftsartikel (refereegranskat)abstract
- Tick-borne encephalitis (TBE) is a viral infection of the CNS caused by TBE virus. With no specific treatment available, the only protection is a formalin-inactivated whole virus vaccine. Primary immunization with European TBE vaccines, as recommended by the manufacturers, consists of three vaccine doses administered within a 1-y period. Protection from vaccination is believed to be mediated by Abs, yet T cells may also have a protective role. We set out to characterize the human CD4(+) T cell response throughout primary TBE immunization. The responses were evaluated before vaccination and 1 mo after each vaccine dose. A heterogeneous magnitude of CD4(+) T cell-mediated memory responses was observed in regard to lymphoblast expansion and cytokine production (IFN-gamma, IL-2, and TNF), with the highest median magnitude detected after the second dose of vaccine. Stimulation with an overlapping peptide library based on structural TBE virus proteins E and C revealed that CD4(+) T cells concomitantly producing IL-2 and TNF dominated the responses from vaccinees after each vaccine dose, whereas a control cohort of TBE patients responded mainly with all three cytokines. CD107a expression was not upregulated upon peptide stimulation in the vaccinees. However, CD154 (CD40L) expression on cytokine-positive memory CD4(+) T cells significantly increased after the second vaccine dose. Taken together, TBE vaccination induced CD4(+) T cell responses dominated by IL-2 and TNF production together with CD154 upregulation and a lower IFN-gamma response compared with TBE patients. This response pattern was consistent after all three doses of TBE vaccine.
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| 7. |
- Albinsson, Bo, et al.
(författare)
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Distinction between serological responses following tick-borne encephalitis virus (TBEV) infection vs vaccination, Sweden 2017
- 2018
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Ingår i: Eurosurveillance. - 1025-496X .- 1560-7917. ; 23:3, s. 2-7
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Tidskriftsartikel (refereegranskat)abstract
- Tick-borne encephalitis virus (TBEV) is an important European vaccine-preventable pathogen. Discrimination of vaccine-induced antibodies from those elicited by infection is important. We studied anti-TBEV IgM/IgG responses, including avidity and neutralisation, by multiplex serology in 50 TBEV patients and 50 TBEV vaccinees. Infection induced antibodies reactive to both whole virus (WV) and non-structural protein 1 (NS1) in 48 clinical cases, whereas 47 TBEV vaccinees had WV, but not NS1 antibodies, enabling efficient discrimination of infection/vaccination.
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| 8. |
- Andersson, Håkan, et al.
(författare)
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Well-Tolerated Chemoprophylaxis Uniformly Prevented Swedish Soldiers from Plasmodium falciparum Malaria in Liberia, 2004-2006
- 2008
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Ingår i: Military medicine. - 0026-4075 .- 1930-613X. ; 173:12, s. 1194-1198
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Tidskriftsartikel (refereegranskat)abstract
- Background: Between 2004 and 2006, 1,170 Swedish soldiers were deployed to Liberia. They were prescribed mefloquine or atovaquone/proguanil as malaria chemoprophylaxis. Our study aims were to estimate the chemoprophylaxis effectiveness and adverse events. Methods: Cases of malaria were routinely reported during and after the mission. After return to Sweden, the soldiers filled in a questionnaire concerning type of accommodation, use of prophylaxis, and adverse events. Results: No cases of Plasmodium falciparum malaria were recorded during a total of 7,000 person-months. Adverse events (AE) were reported by 57% in the mefloquine group and 34% in the atovaquone/proguanil group. In the mefloquine group, the soldiers reported more neuropsychological AE. Conclusions: Both drugs were safe and 100% effective as lone-term prophylaxis for prevention of P. falciparum malaria. Atovaquone/proguanil was better tolerated with respect to self-reported AE.
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| 9. |
- Askling, Helena H., et al.
(författare)
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Hepatitis A Risk in Travelers
- 2009
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Ingår i: Journal of Travel Medicine. - : Oxford University Press (OUP). - 1195-1982 .- 1708-8305. ; 16:4, s. 233-238
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Tidskriftsartikel (refereegranskat)abstract
- Background Traveling to highly endemic areas for hepatitis A is increasing while the immunization level in travelers has been shown to be low in the countries studied. Methods In this population-based study, we have estimated the incidence rate of travel-related hepatitis A during 1997 to 2005 by use of the Swedish notification system of communicable diseases and an ongoing national database on travel patterns. We have also acquired airport-based immunization data from 2007. Results During the study period, 636 cases of travel-related hepatitis A were notified. Traveling to East Africa was associated with the highest incidence rate (14.1 cases/100,000 person months), followed by the Middle East (5.8/100,000 person months), and India with neighboring countries (5.6/100,000 person months). Visiting Friends and Relatives (VFR) travelers represented 83, 91, and 70% of the cases to these three regions. By age-group, the highest incidence was found in children 0 to 14 years (3.1/100,000 travelers) where 88% of the cases were VFR travelers. Incidence rate in unprotected travelers to East Asia, North Africa, and the Middle East was 2, 12, and 18 cases/100,000 person months, respectively. In 2007, 79% of the travelers were immunized against hepatitis A. Conclusions We conclude that travelers, and especially children, who are VFR in endemic areas constitute a high-risk group for acquiring hepatitis A infection, while the risk for unprotected tourists to East Asia is low.
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| 10. |
- Askling, Helena H., et al.
(författare)
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Hepatitis A vaccine for immunosuppressed patients with rheumatoid arthritis : a prospective, open-label, multi-centre study
- 2014
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Ingår i: Travel Medicine and Infectious Disease. - : Elsevier BV. - 1477-8939 .- 1873-0442. ; 12:2, s. 134-42
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Hepatitis A vaccine is the most frequently used travel vaccine, yet data are scarce about its ability to induce protection in patients with concurrent immunosuppressive treatment. We assessed the immunogenicity of this vaccine in rheumatoid arthritis (RA) patients treated with tumour necrosis factor-inhibitors (TNFi) and/or methotrexate (MTX).METHODS: Hepatitis A vaccine was administered to non-immune RA patients at 0 and 6 months. Hepatitis A virus (HAV) antibodies were assessed at 0, 1, 6, 7, 12, and 24 months with a quantitative Chemiluminescent Microparticle Immuno Assay (CMIA) for HAV-IgG. Samples from month 1, 6, and 7 were, in addition, analysed with a microparticle EIA (MEIA) for anti-HAV IgM + IgG.RESULTS: The final study population consisted of 53 patients treated with TNFi (n = 15), TNFi + MTX (n = 21) or MTX (n = 17). One and six months after the first dose, 10% and 33% of the patients had attained seroprotection. One and six months after the second dose 83% and 72% were seroprotected. At month 24, 86% of the vaccinees showed protective levels.CONCLUSIONS: Two doses of hepatitis A vaccine at a 6-month interval provided protection for most immunosuppressed RA patients. A single dose does not seem to afford sufficient protection to this group of patients.
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| 11. |
- Askling, H. H., et al.
(författare)
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Immunogenicity of delayed TBE-vaccine booster
- 2012
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 30:3, s. 499-502
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Tidskriftsartikel (refereegranskat)abstract
- Information is scarce regarding the antibody response when TBE-vaccine booster doses are delayed, which is a common situation in daily life. We have investigated the immune response after a delayed booster dose compared to a normal booster interval in an every-day setting. Overall, 250/260 (96%) of the study participants had neutralizing antibodies post-booster, with no significant difference between normal and delayed booster intervals. Based on our findings we propose that healthy individuals who have failed adherence to the recommended schedule of TBE-vaccination can be given a delayed dose without concern of immunogenicity.
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| 12. |
- Askling, Helena H., et al.
(författare)
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Influenza in travellers
- 2010
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Ingår i: Current Opinion in Infectious Diseases. - 0951-7375 .- 1473-6527. ; 23:5, s. 421-425
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Forskningsöversikt (refereegranskat)abstract
- Purpose of review The importance of travelling as an important factor for spread of influenza has become even more evident during the recent pandemic year. All the same, the mechanism for seasonal spreading of influenza is not yet fully understood. Recent findings The incidence of influenza in returning febrile travellers from subtropical and tropical regions is between 5 and 15% with no significant differences between those vaccinated and not vaccinated in the reviewed studies. The power of the studies to detect differences are, however, low. In these studies, 12-85% of the travellers or pilgrims were vaccinated against influenza. Air transportation, and especially long-haul flight, is a key factor for the spread of influenza even though travel restrictions seem to be of no use for preventing a pandemic spread. Summary Influenza should always be considered in a febrile traveller with or without respiratory symptoms. Future studies on incidence of travel-related influenza should consider the short incubation period for a better estimate. Vaccine from the opposite hemisphere should be made available for travellers, and influenza vaccine studies should focus on optimizing the effect of the vaccine in the elderly and immunocompromised.
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| 13. |
- Bernstein, Henry H., et al.
(författare)
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Comparison of the safety and immunogenicity of a refrigerator-stable versus a frozen formulation of ProQuad (measles, mumps, rubella, and varicella virus vaccine live)
- 2007
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Ingår i: Pediatrics. - : American Academy of Pediatrics (AAP). - 1098-4275 .- 0031-4005. ; 119:6, s. 1299-1305
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Tidskriftsartikel (refereegranskat)abstract
- Objective. A refrigerator-stable formulation of ProQuad has been developed to expand the utility of ProQuad to areas in which maintenance of a frozen cold chain (- 15 degrees C or colder) during storage and transport may not be feasible. The objective of this study was to demonstrate that the immunogenicity and safety profiles of a refrigerator-stable formulation of ProQuad are similar to the recently licensed frozen formulation. Methods. In this double-blind, randomized, multicenter study, healthy 12- to 23-month- old children with negative vaccination and clinical histories for measles, mumps, rubella, varicella, and zoster were vaccinated with either the refrigerator-stable formulation of ProQuad (N = 1006) or the frozen formulation of ProQuad (N = 513). Patients were followed for 42 days after vaccination for adverse experiences. Immunogenicity was evaluated 6 weeks after vaccination. Results. The refrigerator-stable formulation of ProQuad was generally well tolerated. The incidence of adverse experiences was similar between groups. No vaccine-related serious adverse experiences were reported. For both groups, the response rate was >= 97.7% for measles, mumps, and rubella, and the percentage of patients with a varicella zoster virus antibody titer of >= 5 U/mL glycoprotein antigen-based enzyme-linked immunosorbent assay after vaccination was >= 88.8%. The geometric mean titers for all antigens were numerically slightly higher in patients who received the refrigerator-stable formulation. Conclusions. The refrigerator-stable formulation of ProQuad is generally well tolerated, highly immunogenic, and noninferior in terms of postvaccination antibody responses. This refrigerator-stable formulation may improve ease of vaccine administration, increase use of the vaccine throughout the world because of its improved storage conditions, and replace the frozen formulation of ProQuad or any dose of M-M-RII and Varivax in routine practice.
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| 14. |
- Boutry, Céline, et al.
(författare)
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The Adjuvanted Recombinant Zoster Vaccine Confers Long-Term Protection Against Herpes Zoster : Interim Results of an Extension Study of the Pivotal Phase 3 Clinical Trials ZOE-50 and ZOE-70
- 2022
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press. - 1058-4838 .- 1537-6591. ; 74:8, s. 1459-1467
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Tidskriftsartikel (refereegranskat)abstract
- Efficacy against herpes zoster and immune responses to the adjuvanted recombinant zoster vaccine plateaued at high levels between 5.1 and 7.1 years (mean) post-vaccination, suggesting that its clinical benefit in older adults is sustained for at least 7 years post-vaccination. Background This ongoing follow-up study evaluated the persistence of efficacy and immune responses for 6 additional years in adults vaccinated with the glycoprotein E (gE)-based adjuvanted recombinant zoster vaccine (RZV) at age >= 50 years in 2 pivotal efficacy trials (ZOE-50 and ZOE-70). The present interim analysis was performed after >= 2 additional years of follow-up (between 5.1 and 7.1 years [mean] post-vaccination) and includes partial data for year (Y) 8 post-vaccination. Methods Annual assessments were performed for efficacy against herpes zoster (HZ) from Y6 post-vaccination and for anti-gE antibody concentrations and gE-specific CD4[2+] T-cell (expressing >= 2 of 4 assessed activation markers) frequencies from Y5 post-vaccination. Results Of 7413 participants enrolled for the long-term efficacy assessment, 7277 (mean age at vaccination, 67.2 years), 813, and 108 were included in the cohorts evaluating efficacy, humoral immune responses, and cell-mediated immune responses, respectively. Efficacy of RZV against HZ through this interim analysis was 84.0% (95% confidence interval [CI], 75.9-89.8) from the start of this follow-up study and 90.9% (95% CI, 88.2-93.2) from vaccination in ZOE-50/70. Annual vaccine efficacy estimates were >84% for each year since vaccination and remained stable through this interim analysis. Anti-gE antibody geometric mean concentrations and median frequencies of gE-specific CD4[2+] T cells reached a plateau at approximately 6-fold above pre-vaccination levels. Conclusions Efficacy against HZ and immune responses to RZV remained high, suggesting that the clinical benefit of RZV in older adults is sustained for at least 7 years post-vaccination.
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| 15. |
- Carlsson, Anja M, et al.
(författare)
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Plasmodium falciparum population dynamics during the early phase of anti-malarial drug treatment in Tanzanian children with acute uncomplicated malaria
- 2011
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Ingår i: Malaria Journal. - : Springer Science and Business Media LLC. - 1475-2875. ; 10, s. 380-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:This study aimed to explore Plasmodium falciparum population dynamics during the early phase of anti-malarial drug treatment with artemisinin-based combination therapy in children with clinical malaria in a high transmission area in Africa.METHODS:A total of 50 children aged 1-10 years with acute uncomplicated P. falciparum malaria in Bagamoyo District, Tanzania, were enrolled. Participants were hospitalized and received supervised standard treatment with artemether-lumefantrine according to body weight in six doses over 3 days. Blood samples were collected 11 times, i.e. at time of diagnosis (-2 h) and 0, 2, 4, 8, 16, 24, 36, 48, 60 and 72 h after initiation of treatment. Parasite population dynamics were assessed using nested polymerase chain reaction (PCR)-genotyping of merozoite surface protein (msp) 1 and 2.RESULTS:PCR-analyses from nine sequential blood samples collected after initiation of treatment identified 20 and 21 additional genotypes in 15/50 (30%) and 14/50 (28%) children with msp1 and msp2, respectively, non-detectable in the pre-treatment samples (-2 and 0 h combined). Some 15/20 (75%) and 14/21 (67%) of these genotypes were identified within 24 h, whereas 17/20 (85%) and 19/21 (90%) within 48 h for msp1 and msp2, respectively. The genotype profile was diverse, and varied considerably over time both within and between patients, molecular markers and their respective families.CONCLUSION:PCR analyses from multiple blood samples collected during the early treatment phase revealed a complex picture of parasite sub-populations. This underlines the importance of interpreting PCR-outcomes with caution and suggests that the present use of PCR-adjustment from paired blood samples in anti-malarial drug trials may overestimate assessment of drug efficacy in high transmission areas in Africa.The study is registered at http://www.clinicaltrials.gov with identifier NCT00336375.
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| 16. |
- Chlibek, Roman, et al.
(författare)
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Long-term immunogenicity and safety of an investigational herpes zoster subunit vaccine in older adults
- 2016
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 34:6, s. 863-868
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Tidskriftsartikel (refereegranskat)abstract
- Background: An investigational subunit vaccine containing the varicella-zoster virus (VZV) glycoprotein E (gE) and the AS01(B) adjuvant system is being evaluated for the prevention of herpes zoster (HZ) in older adults. A phase II trial evaluating different formulations of this vaccine (containing 25 mu g, 50 mu g, or 100 mu g gE) was conducted in adults >= 60 years of age and showed that all formulations elicited robust cellular and humoral immune responses for up to 3 years after vaccination. In this follow-up study in subjects who received two doses of the 50 mu g gE/AS01(B) formulation (HZ/su), we assessed the persistence of the immune responses for up to 6 years after vaccination. Methods: This phase II, open-label, multicenter, single-group trial conducted in the Czech Republic, Germany, Sweden, and the Netherlands followed 129 subjects who had received two doses (2 months apart) of HZ/su during the initial trial. Vaccine-induced immune responses (frequencies of gE-specific CD4(+) T cells expressing >= 2 activation markers and serum anti-gE antibody concentrations) were evaluated at 48, 60, and 72 months after the first HZ/su dose. Results: Six years after vaccination with HZ/su, gE-specific cell-mediated immune responses and anti-gE antibody concentrations had decreased by 20-25% from month 36, but remained higher than the prevaccination values. At month 72, the gE-specific cell-mediated immune response was 3.8 times higher than the prevaccination value (477.3 vs. 119.4 activated gE-specific CD4(+) T cells per 10(6) cells), and the anti-gE antibody concentration was 7.3 times higher than the prevaccination value (8159.0 vs. 1121.3 mIU/mL). No vaccine-related serious adverse events were reported between months 36 and 72. Conclusions: gE-specific cellular and humoral immune responses persisted for 6 years after two-dose vaccination with HZ/su in healthy older adults. No safety concerns were identified.
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| 17. |
- Chlibek, Roman, et al.
(författare)
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Safety and immunogenicity of three different formulations of an adjuvanted varicella-zoster virus subunit candidate vaccine in older adults : A phase II, randomized, controlled study
- 2014
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 32:15, s. 1745-1753
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Tidskriftsartikel (refereegranskat)abstract
- Background: This study investigated the safety and immunogenicity of different formulations and schedules of a candidate subunit herpes zoster vaccine containing varicella-zoster virus glycoprotein E (gE) with or without the adjuvant system ASO1(B). Methods: In this phase II, single-blind, randomized, controlled study, adults aged >= 60 years (N = 714) received one dose of 100 mu g gE/AS01(B), two doses, two months apart, of 25, 50, or 100 mu g gE/AS01(B), or two doses of unadjuvanted 100 mu g gE/saline. Frequencies of CD4(+) T cells expressing >= 2 activation markers following induction with gE were measured by intracellular cytokine staining and serum anti-gE antibody concentrations by ELISA. Results: Frequencies of gE-specific CD4(+) T cells were >3-fold higher after two doses of all gE/AS01(B) formulations than after one dose of 100 mu g gE/AS01(B) or two doses of 100 mu g gE/saline. Frequencies were comparable after two doses of 25, 50, or 100 mu g gE/AS01g. Serum anti-gE antibody concentrations were comparable after two doses of 50 or 100 mu g gE/AS01(B) and higher than in the other groups. Immune responses persisted for at least 36 months. Reactogenicities of all gE/AS01(B) formulations were similar but greater than with gE/saline. Conclusions: The three formulations of gE/AS01(B) were immunogenic and well tolerated in adults aged >= 60 years. Two vaccinations with gE/AS01(B) induced higher immune responses than one and the dose of gE impacted humoral but not cellular immune responses (NCT00434577).
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| 18. |
- Cunningham, A. L., et al.
(författare)
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Efficacy of the Herpes Zoster Subunit Vaccine in Adults 70 Years of Age or Older
- 2016
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 375:11, s. 1019-1032
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND A trial involving adults 50 years of age or older (ZOE-50) showed that the herpes zoster subunit vaccine (HZ/su) containing recombinant varicella-zoster virus glycoprotein E and the AS01(B) adjuvant system was associated with a risk of herpes zoster that was 97.2% lower than that associated with placebo. A second trial was performed concurrently at the same sites and examined the safety and efficacy of HZ/su in adults 70 years of age or older (ZOE-70). METHODS This randomized, placebo-controlled, phase 3 trial was conducted in 18 countries and involved adults 70 years of age or older. Participants received two doses of HZ/su or placebo (assigned in a 1: 1 ratio) administered intramuscularly 2 months apart. Vaccine efficacy against herpes zoster and postherpetic neuralgia was assessed in participants from ZOE-70 and in participants pooled from ZOE-70 and ZOE-50. RESULTS In ZOE-70, 13,900 participants who could be evaluated (mean age, 75.6 years) received either HZ/su (6950 participants) or placebo (6950 participants). During a mean follow-up period of 3.7 years, herpes zoster occurred in 23 HZ/su recipients and in 223 placebo recipients (0.9 vs. 9.2 per 1000 person-years). Vaccine efficacy against herpes zoster was 89.8% (95% confidence interval [CI], 84.2 to 93.7; P<0.001) and was similar in participants 70 to 79 years of age (90.0%) and participants 80 years of age or older (89.1%). In pooled analyses of data from participants 70 years of age or older in ZOE-50 and ZOE-70 (16,596 participants), vaccine efficacy against herpes zoster was 91.3% (95% CI, 86.8 to 94.5; P<0.001), and vaccine efficacy against postherpetic neuralgia was 88.8% (95% CI, 68.7 to 97.1; P<0.001). Solicited reports of injection-site and systemic reactions within 7 days after injection were more frequent among HZ/su recipients than among placebo recipients (79.0% vs. 29.5%). Serious adverse events, potential immune-mediated diseases, and deaths occurred with similar frequencies in the two study groups. CONCLUSIONS In our trial, HZ/su was found to reduce the risks of herpes zoster and postherpetic neuralgia among adults 70 years of age or older. (Funded by GlaxoSmithKline Biologicals; ZOE-50 and ZOE-70 ClinicalTrials.govnumbers, NCT01165177 and NCT01165229.)
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| 19. |
- Dahal, Prabin, et al.
(författare)
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Competing risk events in antimalarial drug trials in uncomplicated Plasmodium falciparum malaria : a WorldWide Antimalarial Resistance Network individual participant data meta-analysis
- 2019
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Ingår i: Malaria Journal. - : BMC. - 1475-2875. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Background: Therapeutic efficacy studies in uncomplicated Plasmodium falciparum malaria are confounded by new infections, which constitute competing risk events since they can potentially preclude/pre-empt the detection of subsequent recrudescence of persistent, sub-microscopic primary infections.Methods: Antimalarial studies typically report the risk of recrudescence derived using the Kaplan-Meier (K-M) method, which considers new infections acquired during the follow-up period as censored. Cumulative Incidence Function (CIF) provides an alternative approach for handling new infections, which accounts for them as a competing risk event. The complement of the estimate derived using the K-M method (1 minus K-M), and the CIF were used to derive the risk of recrudescence at the end of the follow-up period using data from studies collated in the WorldWide Antimalarial Resistance Network data repository. Absolute differences in the failure estimates derived using these two methods were quantified. In comparative studies, the equality of two K-M curves was assessed using the log-rank test, and the equality of CIFs using Gray's k-sample test (both at 5% level of significance). Two different regression modelling strategies for recrudescence were considered: cause-specific Cox model and Fine and Gray's sub-distributional hazard model.Results: Data were available from 92 studies (233 treatment arms, 31,379 patients) conducted between 1996 and 2014. At the end of follow-up, the median absolute overestimation in the estimated risk of cumulative recrudescence by using 1 minus K-M approach was 0.04% (interquartile range (IQR): 0.00-0.27%, Range: 0.00-3.60%). The overestimation was correlated positively with the proportion of patients with recrudescence [Pearson's correlation coefficient (rho): 0.38, 95% Confidence Interval (CI) 0.30-0.46] or new infection [rho: 0.43; 95% CI 0.35-0.54]. In three study arms, the point estimates of failure were greater than 10% (the WHO threshold for withdrawing antimalarials) when the K-M method was used, but remained below 10% when using the CIF approach, but the 95% confidence interval included this threshold.Conclusions: The 1 minus K-M method resulted in a marginal overestimation of recrudescence that became increasingly pronounced as antimalarial efficacy declined, particularly when the observed proportion of new infection was high. The CIF approach provides an alternative approach for derivation of failure estimates in antimalarial trials, particularly in high transmission settings.
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| 20. |
- Dahal, Prabin, et al.
(författare)
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Temporal distribution of Plasmodium falciparum recrudescence following artemisinin-based combination therapy : an individual participant data meta-analysis
- 2022
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Ingår i: Malaria Journal. - : Springer Nature. - 1475-2875. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- Background: The duration of trial follow-up affects the ability to detect recrudescent infections following anti-malarial treatment. The aim of this study was to explore the proportions of recrudescent parasitaemia as ascribed by genotyping captured at various follow-up time-points in treatment efficacy trials for uncomplicated Plasmodium falciparum malaria.Methods: Individual patient data from 83 anti-malarial efficacy studies collated in the WorldWide Antimalarial Resistance Network (WWARN) repository with at least 28 days follow-up were available. The temporal and cumulative distributions of recrudescence were characterized using a Cox regression model with shared frailty on study-sites. Fractional polynomials were used to capture non-linear instantaneous hazard. The area under the density curve (AUC) of the constructed distribution was used to estimate the optimal follow-up period for capturing a P. falciparum malaria recrudescence. Simulation studies were conducted based on the constructed distributions to quantify the absolute overestimation in efficacy due to sub-optimal follow-up.Results: Overall, 3703 recurrent infections were detected in 60 studies conducted in Africa (15,512 children aged < 5 years) and 23 studies conducted in Asia and South America (5272 patients of all ages). Using molecular genotyping, 519 (14.0%) recurrences were ascribed as recrudescent infections. A 28 day artemether-lumefantrine (AL) efficacy trial would not have detected 58% [95% confidence interval (CI) 47-74%] of recrudescences in African children and 32% [95% CI 15-45%] in patients of all ages in Asia/South America. The corresponding estimate following a 42 day dihydroartemisinin-piperaquine (DP) efficacy trial in Africa was 47% [95% CI 19-90%] in children under 5 years old treated with > 48 mg/kg total piperaquine (PIP) dose and 9% [95% CI 0-22%] in those treated with <= 48 mg/kg PIP dose. In absolute terms, the simulation study found that trials limited to 28 days follow-up following AL underestimated the risk of recrudescence by a median of 2.8 percentage points compared to day 63 estimates and those limited to 42 days following DP underestimated the risk of recrudescence by a median of 2.0 percentage points compared to day 42 estimates. The analysis was limited by few clinical trials following patients for longer than 42 days (9 out of 83 trials) and the imprecision of PCR genotyping which overcalls recrudescence in areas of higher transmission biasing the later distribution.Conclusions: Restricting follow-up of clinical efficacy trials to day 28 for AL and day 42 for DP will miss a proportion of late recrudescent treatment failures but will have a modest impact in derived efficacy. The results highlight that as genotyping methods improve consideration should be given for trials with longer duration of follow-up to detect early indications of emerging drug resistance.
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| 21. |
- Diogenes, Maria Jose, et al.
(författare)
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Extracellular Alpha-Synuclein Oligomers Modulate Synaptic Transmission and Impair LTP Via NMDA-Receptor Activation
- 2012
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Ingår i: Journal of Neuroscience. - 0270-6474 .- 1529-2401. ; 32:34, s. 11750-11762
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Tidskriftsartikel (refereegranskat)abstract
- Parkinson's disease (PD) is the most common representative of a group of disorders known as synucleinopathies, in which misfolding and aggregation of alpha-synuclein (a-syn) in various brain regions is the major pathological hallmark. Indeed, the motor symptoms in PD are caused by a heterogeneous degeneration of brain neurons not only in substantia nigra pars compacta but also in other extrastriatal areas of the brain. In addition to the well known motor dysfunction in PD patients, cognitive deficits and memory impairment are also an important part of the disorder, probably due to disruption of synaptic transmission and plasticity in extrastriatal areas, including the hippocampus. Here, we investigated the impact of a-syn aggregation on AMPA and NMDA receptor-mediated rat hippocampal (CA3-CA1) synaptic transmission and long-term potentiation (LTP), the neurophysiological basis for learning and memory. Our data show that prolonged exposure to a-syn oligomers, but not monomers or fibrils, increases basal synaptic transmission through NMDA receptor activation, triggering enhanced contribution of calcium-permeable AMPA receptors. Slices treated with a-syn oligomers were unable to respond with further potentiation to theta-burst stimulation, leading to impaired LTP. Prior delivery of a low-frequency train reinstated the ability to express LTP, implying that exposure to a-syn oligomers drives the increase of glutamatergic synaptic transmission, preventing further potentiation by physiological stimuli. Our novel findings provide mechanistic insight on how a-syn oligomers may trigger neuronal dysfunction and toxicity in PD and other synucleinopathies.
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| 22. |
- Ferguson, Murdo, et al.
(författare)
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Lot-to-lot immunogenicity consistency of the respiratory syncytial virus prefusion F protein vaccine in older adults
- 2024
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Ingår i: Vaccine: X. - 2590-1362. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Background: Previous phase 3 studies showed that the AS01E-adjuvanted respiratory syncytial virus (RSV) prefusion F protein-based vaccine for older adults (RSVPreF3 OA) is well tolerated and efficacious in preventing RSV-associated lower respiratory tract disease in adults ≥ 60 years of age. This study evaluated lot-to-lot immunogenicity consistency, reactogenicity, and safety of three RSVPreF3 OA lots. Methods: This phase 3, multicenter, double-blind study randomized (1:1:1) participants ≥ 60 years of age to receive one of three RSVPreF3 OA lots. Serum RSVPreF3-binding immunoglobulin G (IgG) concentration was assessed at baseline and 30 days post-vaccination. Lot-to-lot consistency was demonstrated if the two-sided 95 % confidence intervals (CIs) of the RSVPreF3-binding IgG geometric mean concentration (GMC) ratios between each lot pair at 30 days post-vaccination were within 0.67 and 1.50. Solicited adverse events (AEs) within four days, unsolicited AEs within 30 days, and serious AEs (SAEs) and potential immune-mediated diseases within six months post-vaccination were recorded. Results: A total of 757 participants received RSVPreF3 OA, of whom 708 were included in the per-protocol set (234, 237, and 237 participants for each lot). Lot-to-lot consistency was demonstrated: GMC ratios were 1.06 (95 % CI: 0.94–1.21), 0.92 (0.81–1.04), and 0.87 (0.77–0.99) between the lot pairs (lot 1/2; 1/3; 2/3). For the three lots, the RSVPreF3-binding IgG concentration increased 11.84-, 11.29-, and 12.46-fold post-vaccination compared to baseline. The reporting rates of solicited and unsolicited AEs, SAEs, and potential immune-mediated diseases were balanced between lots. Twenty-one participants reported SAEs; one of these–a case of atrial fibrillation–was considered by the investigator as vaccine-related. SAEs with a fatal outcome were reported for four participants, none of which were considered by the investigator as vaccine-related. Conclusion: This study demonstrated lot-to-lot immunogenicity consistency of three RSVPreF3 OA vaccine lots and indicated that the vaccine had an acceptable safety profile. ClinicalTrials.gov: NCT05059301.
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| 23. |
- Ferguson, Murdo, et al.
(författare)
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Lot-to-lot immunogenicity consistency of the respiratory syncytial virus prefusion F protein vaccine in older adults
- 2024
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Ingår i: Vaccine: X. - : Elsevier. - 2590-1362. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Background: Previous phase 3 studies showed that the AS01E-adjuvanted respiratory syncytial virus (RSV) prefusion F protein-based vaccine for older adults (RSVPreF3 OA) is well tolerated and efficacious in preventing RSV-associated lower respiratory tract disease in adults ≥ 60 years of age. This study evaluated lot-to-lot immunogenicity consistency, reactogenicity, and safety of three RSVPreF3 OA lots. Methods: This phase 3, multicenter, double-blind study randomized (1:1:1) participants ≥ 60 years of age to receive one of three RSVPreF3 OA lots. Serum RSVPreF3-binding immunoglobulin G (IgG) concentration was assessed at baseline and 30 days post-vaccination. Lot-to-lot consistency was demonstrated if the two-sided 95 % confidence intervals (CIs) of the RSVPreF3-binding IgG geometric mean concentration (GMC) ratios between each lot pair at 30 days post-vaccination were within 0.67 and 1.50. Solicited adverse events (AEs) within four days, unsolicited AEs within 30 days, and serious AEs (SAEs) and potential immune-mediated diseases within six months post-vaccination were recorded. Results: A total of 757 participants received RSVPreF3 OA, of whom 708 were included in the per-protocol set (234, 237, and 237 participants for each lot). Lot-to-lot consistency was demonstrated: GMC ratios were 1.06 (95 % CI: 0.94–1.21), 0.92 (0.81–1.04), and 0.87 (0.77–0.99) between the lot pairs (lot 1/2; 1/3; 2/3). For the three lots, the RSVPreF3-binding IgG concentration increased 11.84-, 11.29-, and 12.46-fold post-vaccination compared to baseline. The reporting rates of solicited and unsolicited AEs, SAEs, and potential immune-mediated diseases were balanced between lots. Twenty-one participants reported SAEs; one of these–a case of atrial fibrillation–was considered by the investigator as vaccine-related. SAEs with a fatal outcome were reported for four participants, none of which were considered by the investigator as vaccine-related. Conclusion: This study demonstrated lot-to-lot immunogenicity consistency of three RSVPreF3 OA vaccine lots and indicated that the vaccine had an acceptable safety profile. ClinicalTrials.gov: NCT05059301. © 2024 GSK
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| 24. |
- Hastie, Andrew, et al.
(författare)
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Immunogenicity of the adjuvanted recombinant zoster vaccine : persistence and anamnestic response to additional doses administered 10 years after primary vaccination.
- 2020
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Ingår i: Journal of Infectious Diseases. - : Oxford University Press (OUP). - 0022-1899 .- 1537-6613. ; 224:12, s. 2025-2034
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The adjuvanted recombinant zoster vaccine (RZV) is highly immunogenic and efficacious in adults ≥50 years (Y) of age (YOA). We evaluated (1) long-term immunogenicity of an initial 2-dose RZV schedule by following-up adults vaccinated at ≥60 YOA and by modeling, and (2) immunogenicity of 2 additional doses administered 10Y post-initial vaccination.METHODS: Persistence of humoral and cell-mediated immune (CMI) responses to 2 initial RZV doses was assessed through 10Y post-initial vaccination, and modeled through 20Y using a Piecewise, Power law and Fraser model. Immunogenicity and safety of 2 additional RZV doses were also evaluated (NCT02735915).RESULTS: Seventy adults were enrolled. Ten years post-initial vaccination, humoral and CMI responses were ~6-fold and ~3.5-fold above pre-initial vaccination levels, respectively. Predicted immune persistence through 20Y post-initial vaccination was similar across the 3 models. Sixty-two participants (82.6±4.4 YOA) received at least 1 additional RZV dose. Strong anamnestic humoral and CMI responses were elicited by 1 additional dose, without further increases after a second additional dose.CONCLUSIONS: Immune responses to an initial 2-dose RZV course persisted for many years in older adults. Strong anamnestic immune responses can be induced by additional dosing 10Y after the initial 2-dose course.
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| 25. |
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