9 research outputs found
Autoimmune Hemolytic Anemia in a Patient with Chronic Myeloid Leukemia: Case Report
No full textAutoimmune hemolytic anemia is an unusual complication in chronic myeloid leukemia on Imatinib. In this case report, it had appeared in 76 year old male patient with major molecular response treated by Imatinib. During the etiological research, we had kept the drug or idiopathic causes. We had treated the patient as idiopathic autoimmune hemolytic anemia without Imatinib interruption and we had noted an improvement in anemia without losing the major molecular response
Efficacy of endemic Algerian essential oils against single and mixed biofilms of Candida albicans and Candida glabrata
No full textInternational audienc
Reactogenicity, immunogenicity and breakthrough infections following heterologous or fractional second dose COVID-19 vaccination in adolescents (Com-COV3): A randomised controlled trial
No full textBackground: This was the first study to investigate the reactogenicity and immunogenicity of heterologous or fractional second dose COVID-19 vaccine regimens in adolescents. Methods: A phase II, single-blind, multi-centre, randomised-controlled trial recruited across seven UK sites from September to November 2021, with follow-up visits to August 2022. Healthy 12-to-16 years olds were randomised (1:1:1) to either 30 µg BNT162b2 (BNT-30), 10 µg BNT162b2 (BNT-10), or NVX-CoV2373 (NVX), 8 weeks after a first 30 µg dose of BNT162b2. The primary outcome was solicited systemic reactions in the week following vaccination. Secondary outcomes included immunogenicity and safety. ‘Breakthrough infection’ analyses were exploratory. Findings: 148 participants were recruited (median age 14 years old, 62% female, 26% anti-nucleocapsid IgG seropositive pre-second dose); 132 participants received a second dose. Reactions were mostly mild-to-moderate, with lower rates in BNT-10 recipients. No vaccine-related serious adverse events occurred. Compared to BNT-30, at 28 days post-second dose anti-spike antibody responses were similar for NVX (adjusted geometric mean ratio [aGMR]) 1.09 95% confidence interval (CI): 0.84, 1.42] and lower for BNT-10 (aGMR 0.78 [95% CI: 0.61, 0.99]). For Omicron BA.1 and BA.2, the neutralising antibody titres for BNT-30 at day 28 were similar for BNT-10 (aGMR 1.0 [95% CI: 0.65, 1.54] and 1.02 [95% CI: 0.71, 1.48], respectively), but higher for NVX (aGMR 1.7 [95% CI: 1.07, 2.69] and 1.43 [95% CI: 0.96, 2.12], respectively). Compared to BNT-30, cellular immune responses were greatest for NVX (aGMR 1.73 [95% CI: 0.94, 3.18]), and lowest for BNT-10 (aGMR 0.65 [95% CI: 0.37, 1.15]) at 14 days post-second dose. Cellular responses were similar across the study arms by day 236 post-second dose. Amongst SARS-CoV-2 infection naïve participants, NVX participants had an 89% reduction in risk of self-reported ‘breakthrough infection’ compared to BNT-30 (adjusted hazard ratio [aHR] 0.11 [95% CI: 0.01, 0.86]) up until day 132 after second dose. BNT-10 recipients were more likely to have a ‘breakthrough infection’ compared to BNT-30 (aHR 2.14 [95% CI: 1.02, 4.51]) up to day 132 and day 236 post-second dose. Antibody responses at 132 and 236 days after second dose were similar for all vaccine schedules. Interpretation: Heterologous and fractional dose COVID-19 vaccine schedules in adolescents are safe, well-tolerated and immunogenic. The enhanced performance of the heterologous schedule using NVX-CoV2373 against the Omicron SARS-CoV-2 variant suggests this mRNA prime and protein-subunit boost schedule may provide a greater breadth of protection than the licensed homologous schedule. Funding: National Institute for Health Research and Vaccine Task Force. Trial Registration: International Standard Randomised Controlled Trial Number registry: 12348322
Understanding the interaction of upper respiratory tract infection with respiratory syncytial virus and Streptococcus pneumoniae using a human challenge model: a multicenter, randomized controlled study protocol
No full textBackground: Streptococcus pneumoniae (pneumococcus) and respiratory syncytial virus (RSV) are major causes of respiratory infections globally. Viral and bacterial co-infections are commonly observed in respiratory infections and there is evidence that these pathogens interact synergistically to evade host responses and lead to more severe disease. Notably, RSV seasonal outbreaks are associated with increased hospitalization and a subsequent peak in invasive pneumococcal disease cases, particularly in pediatric populations. Here, we summarize a protocol for a controlled human infection model aiming to evaluate pathogen interaction dynamics and immune responses in a combined pneumococcus and RSV model. The primary objective is to determine whether primary RSV challenge increases the risk of secondary pneumococcal colonization. Methods: This is an open-label, multi-center, randomized controlled human co-infection study, inclusive of a pilot phase. Individuals will be randomized to primary inoculation with either pneumococcus (serotype 6B) or RSV (subtype RSV-A) intra-nasally on day 0 followed by a reciprocal challenge on day 7. During pilot phase A up to 10 participants will be monitored in an in-patient facility for 7–10 days following RSV-A challenge. If there are no safety concerns, we will then progress to an outpatient phase where participants will self-isolate at home. Clinical samples to be taken from participants include nasal swabs and washes for pathogen detection; and nasal cells, nasal lining fluid, and blood samples to examine mucosal and systemic immune responses. Discussion: This work will lead to important scientific knowledge on the interaction and dynamics between pneumococcus and RSV. This knowledge could help inform pneumococcal and RSV vaccination strategies, particularly for groups at risk of developing severe pneumococcal and RSV disease. Trial registration: The study is registered on ISRCTN (The UKs Clinical Study Registry). DOI https://doi.org/10.1186/ISRCTN1203690
Persistence of immune responses after heterologous and homologous third COVID-19 vaccine dose schedules in the UK: eight-month analyses of the COV-BOOST trial
No full textBackground:
COV-BOOST is a multicentre, randomised, controlled, phase 2 trial of seven COVID-19 vaccines used as a third booster dose in June 2021. Monovalent messenger RNA (mRNA) COVID-19 vaccines were subsequently widely used for the third and fourth-dose vaccination campaigns in high-income countries. Real-world vaccine effectiveness against symptomatic infections following third doses declined during the Omicron wave. This report compares the immunogenicity and kinetics of responses to third doses of vaccines from day (D) 28 to D242 following third doses in seven study arms.
Methods:
The trial initially included ten experimental vaccine arms (seven full-dose, three half-dose) delivered at three groups of six sites. Participants in each site group were randomised to three or four experimental vaccines, or MenACWY control. The trial was stratified such that half of participants had previously received two primary doses of ChAdOx1 nCov-19 (Oxford–AstraZeneca; hereafter referred to as ChAd) and half had received two doses of BNT162b2 (Pfizer–BioNtech, hereafter referred to as BNT). The D242 follow-up was done in seven arms (five full-dose, two half-dose). The BNT vaccine was used as the reference as it was the most commonly deployed third-dose vaccine in clinical practice in high-income countries. The primary analysis was conducted using all randomised and baseline seronegative participants who were SARS-CoV-2 naïve during the study and who had not received a further COVID-19 vaccine for any reason since third dose randomisation.
Results:
Among the 817 participants included in this report, the median age was 72 years (IQR: 55-78) with 50.7% being female. The decay rates of anti-spike IgG between vaccines are different among both populations who received initial doses of ChAd/ChAd and BNT/BNT. In the population that previously received ChAd/ChAd, mRNA vaccines had the highest titre at D242 following their vaccine dose although Ad26.COV2.S (Janssen; hereafter referred to as Ad26) showed slower decay. For people who received BNT/BNT as their initial doses, a slower decay was also seen in the Ad26 and ChAd arms. The anti-spike IgG became significantly higher in the Ad26 arm compared to the BNT arm as early as 3-months following vaccination. Similar decay rates were seen between BNT and half-BNT; the geometric mean ratios ranged from 0.76-0.94 at different time points. The difference in decay rates between vaccines was similar for wild-type live virus-neutralising antibodies and that seen for anti-spike IgG. For cellular responses, the persistence was similar between study arms.
Conclusions:
Heterologous third doses with viral vector vaccines following two doses of mRNA achieve more durable humoral responses compared with three doses of mRNA vaccines. Lower doses of mRNA vaccines could be considered for future booster campaigns
Heterologous COVID-19 vaccine schedule with protein-based prime (NVX-CoV2373) and mRNA boost (BNT162b2) induces strong humoral responses: results from COV-BOOST trial
No full textBackground: Heterologous schedules of booster vaccines for COVID-19 following initial doses of mRNA or adenoviral vector vaccines have been shown to be safe and immunogenic. There are few data on booster doses following initial doses of protein nanoparticle vaccines. Methods: Participants of the phase 3 clinical trial of the COVID-19 vaccine NVX-CoV2373 (EudraCT 2020–004123-16) enroled between September 28 and November 28, 2020, who received 2 doses of NVX-CoV2373 administered 21 days apart were invited to receive a third dose booster vaccine of BNT162b2 (wild type mRNA vaccine) as a sub-study of the COV-BOOST clinical trial, and were followed up for assessment of safety, reactogenicity and immunogenicity to day 242 post-booster. Results: The BNT162b2 booster following two doses of NVX-COV2373 was well-tolerated. Most adverse events were mild to moderate, with no serious vaccine-related adverse events reported. Immunogenicity analysis showed a significant increase in spike IgG titres and T-cell responses post-third dose booster. Specifically, IgG levels peaked at day 14 with a geometric mean concentration (GMC) of 216,255 ELISA laboratory units (ELU)/mL (95% CI 191,083–244,743). The geometric mean fold increase from baseline to day 28 post-boost was 168.6 (95% CI 117.5–241.8). Spike IgG titres were sustained above baseline levels at day 242 with a GMC of 58,686 ELU/mL (95% CI 48,954–74,652), with significant decay between days 28 and 84 (geometric mean ratio 0.58, 95% CI 0.53–0.63). T-cell responses also demonstrated enhancement post-booster, with a geometric mean fold increase of 5.1 (95% CI 2.9–9.0) at day 14 in fresh samples and 3.0 (95% CI 1.8–4.9) in frozen samples as measured by ELISpot. In an exploratory analysis, participants who received BNT162b2 after two doses of NVX-COV2373 exhibited higher anti-spike IgG at Day 28 than those who received homologous three doses of BNT162b2, with a GMR of 5.02 (95% CI: 3.17–7.94). This trend remained consistent across all time points, indicating a similar decay rate between the two schedules. Conclusions: A BNT162b2 third dose booster dose in individuals primed with two doses of NVX-COV2373 is safe and induces strong and durable immunogenic responses, higher than seen in other comparable studies. These findings support the use and investigation of heterologous booster strategies and early investigation of heterologous vaccine technology schedules should be a priority in the development of vaccines against new pathogens
Reactogenicity and immunogenicity following heterologous and homologous third dose COVID-19 vaccination in UK adolescents (Com-COV3): A randomised controlled non-inferiority trial
No full textCopyright \ua9 2025 The Author(s). Published by Elsevier Ltd. All rights reserved. BACKGROUND: The emergence of SARS-CoV2 variants combined with waning vaccine-induced immunity and breakthrough infections has highlighted the need for booster doses to maintain protection against SARS-CoV2 infection and disease. METHODS: Com-COV3 was a phase II, multicentre, randomised controlled trial, recruiting across 11 UK sites from June 2022 to June 2023, with follow-up visits to February 2024. Healthy 12-15-year-olds who had received a two-30 μg dose BNT162b2 primary regimen at least 90 days previously were randomised 1:1:1:1:1 to receive either BNT162b2 30 μg, BNT162b2 10 μg (adult vaccine formulation), BNT162b2 10 μg (paediatric formulation), NVXCoV2373, or Meningococcal B vaccine (control). The primary objective was to determine if SARS-CoV-2 anti-spike antibody following a 10 μg dose of the adult formulation of BNT162b2 was non-inferior to the paediatric formulation at 28 days post-third vaccination. The last five participants were randomised using a 1:3:3:1:1 ratio to prioritise recruitment to the study groups required for the co-primary endpoint. Although recruitment ceased early, the sample size required to fulfil the primary objective was met. FINDINGS: 281 participants were recruited (mean age 14 years old, 57% female). Adverse reactions were mostly mild-to-moderate. Local reactogenicity was mildest following NVXCoV2373. Frequency of adverse events was similar for both full dose and fractional dose BNT162b2 groups. Four serious adverse events occurred: three in the paediatric and one in the adult 10 μg BNT162b2 group. Immunogenicity of 10 μg BNT162b2 (adult) was both non-inferior and superior to that of 10 μg BNT162b2 (paediatric); adjusted geometric mean ratio (aGMR) anti-spike IgG 1.50 (one-sided 95% CI 1.25 to ∞). Compared with 30 μg BNT162b2, anti-spike IgG at day 28 post-third dose were similar in the 10 μg BNT162b2 (adult) group [aGMR 0.93 (95% CI 0.75-1.14)] and significantly lower in the 10 μg BNT162b2 (paediatric) [aGMR 0.64 (95% CI 0.52-0.78)] and NVXCoV2373 [aGMR 0.77 (95% CI 0.63-0.95)] groups. Compared with 30 μg BNT162b2, levels of neutralising antibodies against Omicron BA.5 and XBB.15 were similar across vaccine groups. INTERPRETATION: All booster regimens evaluated elicited a robust immune response. 10 μg fractional adult BNT162b2 vaccine demonstrated similar immunogenicity compared with 30 μg BNT162b2 and superior immunogenicity compared with 10 μg paediatric BNT162b2 vaccine. Fractional doses of the adult BNT162b2 vaccine are an alternative to the paediatric formulation for booster campaigns in adolescents
Understanding the interaction of upper respiratory tract infection with respiratory syncytial virus and Streptococcus pneumoniae using a human challenge model: a multicenter, randomized controlled study protocol
No full textBackground
Streptococcus pneumoniae (pneumococcus) and respiratory syncytial virus (RSV) are major causes of respiratory infections globally. Viral and bacterial co-infections are commonly observed in respiratory infections and there is evidence that these pathogens interact synergistically to evade host responses and lead to more severe disease. Notably, RSV seasonal outbreaks are associated with increased hospitalization and a subsequent peak in invasive pneumococcal disease cases, particularly in pediatric populations. Here, we summarize a protocol for a controlled human infection model aiming to evaluate pathogen interaction dynamics and immune responses in a combined pneumococcus and RSV model. The primary objective is to determine whether primary RSV challenge increases the risk of secondary pneumococcal colonization.
Methods
This is an open-label, multi-center, randomized controlled human co-infection study, inclusive of a pilot phase. Individuals will be randomized to primary inoculation with either pneumococcus (serotype 6B) or RSV (subtype RSV-A) intra-nasally on day 0 followed by a reciprocal challenge on day 7. During pilot phase A up to 10 participants will be monitored in an in-patient facility for 7–10 days following RSV-A challenge. If there are no safety concerns, we will then progress to an outpatient phase where participants will self-isolate at home. Clinical samples to be taken from participants include nasal swabs and washes for pathogen detection; and nasal cells, nasal lining fluid, and blood samples to examine mucosal and systemic immune responses.
Discussion
This work will lead to important scientific knowledge on the interaction and dynamics between pneumococcus and RSV. This knowledge could help inform pneumococcal and RSV vaccination strategies, particularly for groups at risk of developing severe pneumococcal and RSV disease.
Trial registration
The study is registered on ISRCTN (The UKs Clinical Study Registry). DOI https://doi.org/10.1186/ISRCTN1203690
