Immunogenicity and reactogenicity of BNT162b2 booster in ChAdOx1-S-primed participants (CombiVacS): a multicentre, open-label, randomised, controlled, phase 2 trial.

BACKGROUND: To date, no immunological data on COVID-19 heterologous vaccination schedules in humans have been reported. We assessed the immunogenicity and reactogenicity of BNT162b2 (Comirnaty, BioNTech, Mainz, Germany) administered as second dose in participants primed with ChAdOx1-S (Vaxzevria, AstraZeneca, Oxford, UK). METHODS: We did a phase 2, open-label, randomised, controlled trial on adults aged 18-60 years, vaccinated with a single dose of ChAdOx1-S 8-12 weeks before screening, and no history of SARS-CoV-2 infection. Participants were randomly assigned (2:1) to receive either BNT162b2 (0·3 mL) via a single intramuscular injection (intervention group) or continue observation (control group). The primary outcome was 14-day immunogenicity, measured by immunoassays for SARS-CoV-2 trimeric spike protein and receptor binding domain (RBD). Antibody functionality was assessed using a pseudovirus neutralisation assay, and cellular immune response using an interferon-γ immunoassay. The safety outcome was 7-day reactogenicity, measured as solicited local and systemic adverse events. The primary analysis included all participants who received at least one dose of BNT162b2 and who had at least one efficacy evaluation after baseline. The safety analysis included all participants who received BNT162b2. This study is registered with EudraCT (2021-001978-37) and ClinicalTrials.gov (NCT04860739), and is ongoing. FINDINGS: Between April 24 and 30, 2021, 676 individuals were enrolled and randomly assigned to either the intervention group (n=450) or control group (n=226) at five university hospitals in Spain (mean age 44 years [SD 9]; 382 [57%] women and 294 [43%] men). 663 (98%) participants (n=441 intervention, n=222 control) completed the study up to day 14. In the intervention group, geometric mean titres of RBD antibodies increased from 71·46 BAU/mL (95% CI 59·84-85·33) at baseline to 7756·68 BAU/mL (7371·53-8161·96) at day 14 (p<0·0001). IgG against trimeric spike protein increased from 98·40 BAU/mL (95% CI 85·69-112·99) to 3684·87 BAU/mL (3429·87-3958·83). The interventional:control ratio was 77·69 (95% CI 59·57-101·32) for RBD protein and 36·41 (29·31-45·23) for trimeric spike protein IgG. Reactions were mild (n=1210 [68%]) or moderate (n=530 [30%]), with injection site pain (n=395 [88%]), induration (n=159 [35%]), headache (n=199 [44%]), and myalgia (n=194 [43%]) the most commonly reported adverse events. No serious adverse events were reported. INTERPRETATION: BNT162b2 given as a second dose in individuals prime vaccinated with ChAdOx1-S induced a robust immune response, with an acceptable and manageable reactogenicity profile. FUNDING: Instituto de Salud Carlos III. TRANSLATIONS: For the French and Spanish translations of the abstract see Supplementary Materials section.

CD151 identifies an NK cell subset that is enriched in COVID-19 patients and correlates with disease severity.

Severe coronavirus disease 2019 (COVID-19) often leads to acute respiratory distress syndrome and multi-organ dysfunction, driven by a dysregulated immune response, including a cytokine storm with elevated proinflammatory cytokine levels. Natural killer (NK) cells are part of the innate immune system with a fundamental role in the defense against viral infections. However, during COVID-19 acute infection, they exhibit an altered phenotype and impaired functionality contributing to the immunopathogenesis of the disease. In this work, we have studied a cohort of patients with COVID-19 (ranging from mild to severe) by analyzing IL-15, TGF-ß, PlGF and GDF-15 plasma levels and performing multiparametric flow cytometry studies. Our results revealed that severe COVID-19 patients exhibited high levels of IL-15, PlGF and GDF-15, along with an enrichment of an NK cell subset expressing the CD151 tetraspanin, which correlated with IL-15 plasma levels and disease severity. In patients, these CD151+ NK cells displayed a more activated phenotype characterized by an increased expression of HLA-DR, CD38 and granzyme B, a distinct receptor repertoire, with lower levels of CD160 and CD31 and higher levels of CD55 and, remarkably, a higher expression of tissue-resident markers CD103 and the NK cell decidual marker CD9. Last of all, in individuals with severe disease, we identified an expansion of a CD151brightCD9+ NK cell subset, suggesting that these cells play a specific role in COVID-19. Altogether, our findings suggest that CD151+ NK cells may have a relevant role in COVID-19 immunopathogenesis.

Safety and immunogenicity of the protein-based PHH-1V compared to BNT162b2 as a heterologous SARS-CoV-2 booster vaccine in adults vaccinated against COVID-19: a multicentre, randomised, double-blind, non-inferiority phase IIb trial.

Background: A SARS-CoV-2 protein-based heterodimer vaccine, PHH-1V, has been shown to be safe and well-tolerated in healthy young adults in a first-in-human, Phase I/IIa study dose-escalation trial. Here, we report the interim results of the Phase IIb HH-2, where the immunogenicity and safety of a heterologous booster with PHH-1V is assessed versus a homologous booster with BNT162b2 at 14, 28 and 98 days after vaccine administration. Methods: The HH-2 study is an ongoing multicentre, randomised, active-controlled, double-blind, non-inferiority Phase IIb trial, where participants 18 years or older who had received two doses of BNT162b2 were randomly assigned in a 2:1 ratio to receive a booster dose of vaccine-either heterologous (PHH-1V group) or homologous (BNT162b2 group)-in 10 centres in Spain. Eligible subjects were allocated to treatment stratified by age group (18-64 versus ≥65 years) with approximately 10% of the sample enrolled in the older age group. The primary endpoints were humoral immunogenicity measured by changes in levels of neutralizing antibodies (PBNA) against the ancestral Wuhan-Hu-1 strain after the PHH-1V or the BNT162b2 boost, and the safety and tolerability of PHH-1V as a boost. The secondary endpoints were to compare changes in levels of neutralizing antibodies against different variants of SARS-CoV-2 and the T-cell responses towards the SARS-CoV-2 spike glycoprotein peptides. The exploratory endpoint was to assess the number of subjects with SARS-CoV-2 infections ≥14 days after PHH-1V booster. This study is ongoing and is registered with ClinicalTrials.gov, NCT05142553. Findings: From 15 November 2021, 782 adults were randomly assigned to PHH-1V (n = 522) or BNT162b2 (n = 260) boost vaccine groups. The geometric mean titre (GMT) ratio of neutralizing antibodies on days 14, 28 and 98, shown as BNT162b2 active control versus PHH-1V, was, respectively, 1.68 (p < 0.0001), 1.31 (p = 0.0007) and 0.86 (p = 0.40) for the ancestral Wuhan-Hu-1 strain; 0.62 (p < 0.0001), 0.65 (p < 0.0001) and 0.56 (p = 0.003) for the Beta variant; 1.01 (p = 0.92), 0.88 (p = 0.11) and 0.52 (p = 0.0003) for the Delta variant; and 0.59 (p ≤ 0.0001), 0.66 (p < 0.0001) and 0.57 (p = 0.0028) for the Omicron BA.1 variant. Additionally, PHH-1V as a booster dose induced a significant increase of CD4+ and CD8+ T-cells expressing IFN-γ on day 14. There were 458 participants who experienced at least one adverse event (89.3%) in the PHH-1V and 238 (94.4%) in the BNT162b2 group. The most frequent adverse events were injection site pain (79.7% and 89.3%), fatigue (27.5% and 42.1%) and headache (31.2 and 40.1%) for the PHH-1V and the BNT162b2 groups, respectively. A total of 52 COVID-19 cases occurred from day 14 post-vaccination (10.14%) for the PHH-1V group and 30 (11.90%) for the BNT162b2 group (p = 0.45), and none of the subjects developed severe COVID-19. Interpretation: Our interim results from the Phase IIb HH-2 trial show that PHH-1V as a heterologous booster vaccine, when compared to BNT162b2, although it does not reach a non-inferior neutralizing antibody response against the Wuhan-Hu-1 strain at days 14 and 28 after vaccination, it does so at day 98. PHH-1V as a heterologous booster elicits a superior neutralizing antibody response against the previous circulating Beta and the currently circulating Omicron BA.1 SARS-CoV-2 variants in all time points assessed, and for the Delta variant on day 98 as well. Moreover, the PHH-1V boost also induces a strong and balanced T-cell response. Concerning the safety profile, subjects in the PHH-1V group report significantly fewer adverse events than those in the BNT162b2 group, most of mild intensity, and both vaccine groups present comparable COVID-19 breakthrough cases, none of them severe. Funding: HIPRA SCIENTIFIC, S.L.U.

Immune response and reactogenicity after immunization with two-doses of an experimental COVID-19 vaccine (CVnCOV) followed by a third-fourth shot with a standard mRNA vaccine (BNT162b2): RescueVacs multicenter cohort study.

Background: There is no evidence to date on immunogenic response among individuals who participated in clinical trials of COVID-19 experimental vaccines redirected to standard national vaccination regimens. Methods: This multicentre, prospective controlled cohort study included subjects who received a COVID-19 experimental vaccine (CVnCoV)(test group, TG) - and unvaccinated subjects (control group, CG), selected among individuals to be vaccinated according to the Spanish vaccination program. All study subjects received BNT162b2 as a standard national vaccination schedule, except 8 (from CG) who received mRNA-1273 and were excluded from immunogenicity analyses. Anti-RBD antibodies level and neutralising titres (NT50) against G614, Beta, Mu, Delta and Omicron variants were analysed. Reactogenicity was also assessed. Findings: 130 participants (TG:92; CG:38) completed standard vaccination. In TG, median (IQR) of anti-RBD antibodies after first BNT162b2 dose were 10740·0 BAU/mL (4466·0-12500) compared to 29·8 BAU/mL (14·5-47·8) in CG (p <0·0001). Median NT50 (IQR) of G614 was 2674·0 (1865·0-3997·0) in TG and 63·0 (16·0-123·1) in CG (p <0·0001). After second BNT162b2 dose, anti-RBD levels increased to ≥12500 BAU/mL (11625·0-12500) in TG compared to 1859·0 BAU/mL (915·4-3820·0) in CG (p <0·0001). NT50 was 2626·5 (1756·0-5472·0) and 850·4 (525·1-1608·0), respectively (p <0·0001). Variant-specific (Beta, Mu, Omicron) response was also assessed. Most frequent adverse reactions were headache, myalgia, and local pain. No severe AEs were reported. Interpretation: Heterologous BNT162b2 as third and fourth doses in previously suboptimal immunized individuals elicit stronger immune response than that obtained with two doses of BNT162b2. This apparent benefit was also observed in variant-specific response. No safety concerns arose. Funding: Partly funded by the Institute of Health Carlos-III and COVID-19 Fund, co-financed by the European Regional Development Fund (FEDER) "A way to make Europe".

Immunogenic dynamics and SARS-CoV-2 variant neutralisation of the heterologous ChAdOx1-S/BNT162b2 vaccination: Secondary analysis of the randomised CombiVacS study.

Background: The CombiVacS study was designed to assess immunogenicity and reactogenicity of the heterologous ChAdOx1-S/BNT162b2 combination, and 14-day results showed a strong immune response. The present secondary analysis addresses the evolution of humoral and cellular response up to day 180. Methods: Between April 24 and 30, 2021, 676 adults primed with ChAdOx1-S were enrolled in five hospitals in Spain, and randomised to receive BNT162b2 as second dose (interventional group [IG]) or no vaccine (control group [CG]). Individuals from CG received BNT162b2 as second dose and also on day 28, as planned based on favourable results on day 14. Humoral immunogenicity, measured by immunoassay for SARS-CoV-2 receptor binding domain (RBD), antibody functionality using pseudovirus neutralisation assays for the reference (G614), Alpha, Beta, Delta, and Omicron variants, as well as cellular immune response using interferon-γ and IL-2 immunoassays were assessed at day 28 after BNT162b2 in both groups, at day 90 (planned only in the interventional group) and at day 180 (laboratory data cut-off on Nov 19, 2021). This study was registered with EudraCT (2021-001978-37) and ClinicalTrials.gov (NCT04860739). Findings: In this secondary analysis, 664 individuals (441 from IG and 223 from CG) were included. At day 28 post vaccine, geometric mean titres (GMT) of RBD antibodies were 5616·91 BAU/mL (95% CI 5296·49-5956·71) in the IG and 7298·22 BAU/mL (6739·41-7903·37) in the CG (p < 0·0001). RBD antibodies titres decreased at day 180 (1142·0 BAU/mL [1048·69-1243·62] and 1836·4 BAU/mL [1621·62-2079·62] in the IG and CG, respectively; p < 0·0001). Neutralising antibodies also waned from day 28 to day 180 in both the IG (1429·01 [1220·37-1673·33] and 198·72 [161·54-244·47], respectively) and the CG (1503·28 [1210·71-1866·54] and 295·57 [209·84-416·33], respectively). The lowest variant-specific response was observed against Omicron-and Beta variants, with low proportion of individuals exhibiting specific neutralising antibody titres (NT50) >1:100 at day 180 (19% and 22%, respectively). Interpretation: Titres of RBD antibodies decay over time, similar to homologous regimes. Our findings suggested that delaying administration of the second dose did not have a detrimental effect after vaccination and may have improved the response obtained. Lower neutralisation was observed against Omicron and Beta variants at day 180. Funding: Funded by Instituto de Salud Carlos III (ISCIII).

T Cell Activation, Highly Armed Cytotoxic Cells and a Shift in Monocytes CD300 Receptors Expression Is Characteristic of Patients With Severe COVID-19.

COVID-19 manifests with a wide diversity of clinical phenotypes characterized by dysfunctional and exaggerated host immune responses. Many results have been described on the status of the immune system of patients infected with SARS-CoV-2, but there are still aspects that have not been fully characterized or understood. In this study, we have analyzed a cohort of patients with mild, moderate and severe disease. We performed flow cytometric studies and correlated the data with the clinical characteristics and clinical laboratory values of the patients. Both conventional and unsupervised data analyses concluded that patients with severe disease are characterized, among others, by a higher state of activation in all T cell subsets (CD4, CD8, double negative and T follicular helper cells), higher expression of perforin and granzyme B in cytotoxic cells, expansion of adaptive NK cells and the accumulation of activated and immature dysfunctional monocytes which are identified by a low expression of HLA-DR and an intriguing shift in the expression pattern of CD300 receptors. More importantly, correlation analysis showed a strong association between the alterations in the immune cells and the clinical signs of severity. These results indicate that patients with severe COVID-19 have a broad perturbation of their immune system, and they will help to understand the immunopathogenesis of COVID-19.

Efficacy and Usability of eHealth Technologies in Stroke Survivors for Prevention of a New Stroke and Improvement of Self-Management: Phase III Randomized Control Trial.

BACKGROUND: Stroke is a leading cause of severe and long-term disability in developed countries. Around 15 million people suffer a stroke each year, being most of them ischemic due to modifiable risk factors. Adequate self-management abilities may help to manage the consequences of stroke, but it is unknown which specific intervention could be effective to booster these self-management abilities. OBJECTIVE: To evaluate the improvement of self-management in chronic stroke survivors using decision support and self-management system (STARR). METHODS: A randomized, prospective, parallel group, open, and the unicentric pilot trial will be performed. Stroke survivors and their caregivers will be randomly allocated to STARR management or standard of care. Main inclusion criteria are mild to moderate disabled first stroke adult survivor, living at home, able to cope and follow the guidelines and devices, without socio-familial exclusion. All will get a conventional treatment in the acute and subacute phase; however, in the chronic period, cases will use the developed STARR App and Decision Support System. Measurements will be performed at baseline, at 3 months, and at 6 months. Outcome measures are patient-report outcome measure of self-management competency, physical function, risk factor reduction, healthcare resource utilization, knowledge of the condition, mood, and social isolation. DISCUSSION: If effective, the results of this study will enable stroke patients and their caregivers to deal better with the everyday life obstacles of stroke, improve the adherence of the treatment, improve the control of cardiovascular risk, and, in consequence, reduce the recurrence of secondary strokes, the number of complications, the number of consultations, and readmissions; to ultimately reduce the health systems costs. Taking into consideration that the number of stroke survivors is increasing around the world, a large number of individuals could profit from this intervention.

Participation in a population-based screening for colorectal cancer using the faecal immunochemical test decreases mortality in 5 years.

BACKGROUND: The steady increase in colorectal cancer (CRC) could be reversed through timely secondary prevention (screening) as a main strategy. The aims of this study were to determine the main features of CRC, survival rate and related factors for different types of identified CRCs in a population-based screening programme using the faecal immunochemical test (FIT). MATERIALS AND METHODS: The CRCs in the susceptible population to be screened between 2009 and 2014 were identified and classified into four groups: (a) nonscreening-detected CRC (diagnosed before first screening invitation and nonparticipants), (b) screening-detected CRC, (c) interval cancer (IC) FIT (diagnosed between screening rounds after a negative FIT) and (d) IC colonoscopy (diagnosed before the colonoscopy surveillance, which is recommended after the screening colonoscopy). Patient demographics and epidemiological characteristics, tumour characteristics and survival were compared between the four groups. RESULTS: 5909 individuals were diagnosed with a CRC. The median follow-up of survival was 4.6 years (range: 0-9 years). The study highlights a significant difference (P<0.0001) in the 5-year survival in the screening-detected CRC group compared with those who had nonscreening-detected CRCs (90.1 vs. 66.7%). Although ICs are not desirable events, the 5-year survival rate is significantly higher with respect to nonparticipants (P<0.0001) (76.3 vs. 60.5%), this being the group with the lowest survival rate. CONCLUSION: The significantly higher 5-year survival rate of 23.4% of the participants in the screening programme suggests that incidence and mortality rates of CRC will decrease in the near future for participants in screening programmes. A high participation rate is essential to achieve health benefits, irrespective of the type of participation.

Screening colonoscopy and risk of adverse events among individuals undergoing fecal immunochemical testing in a population-based program: A nested case-control study.

BACKGROUND: Screening by means of biennial fecal occult blood test has provided a reduction in overall colorectal cancer mortality. Notwithstanding, we should not underestimate the harms that it can produce. AIM: The aim of this article is to identify the independent risk factors of complications after a screening colonoscopy. METHODS: A six-year, nested case-control study was conducted. Mortality/complications within 30 days after colonoscopy were registered and its predictors identified through logistic regression. RESULTS: After 39,254 colonoscopies, the complication rate was 1.0%. Independent predictors were sex (OR 1.68 for men; CI 95% 1.18-2.39), ASA physical status classification system (OR 1.73 for ASA II-III; CI 95% 1.53-3.69), history of abdominal surgery (OR 2.37; CI 95% 1.72-4.08), diverticulosis (OR 2.89; CI 95% 1.94-4.30), inadequate cleansing (OR 29.35; CI 95% 6.52-132.17), detection of advanced neoplasia (AN) (OR 4.92; CI 95% 3.29-7.36), detection of stage I adenocarcinoma (OR 9.44; CI 95% 4.46-20.0), polyps in right colon OR 2.27 CI 95% 1.38-3.74) and complex polypectomy (OR 2.00; CI 95% 1.25-3.20). The logistic model explained 82% of the complications (CI 95% 0.798-0.854, p < 0.001). CONCLUSIONS: Colonoscopy, with or without removal of a lesion, is an invasive procedure with a non-deniable risk of major complications. Factors like inadequate cleansing or detection of AN are determinants. Therefore, it is vital to know which aspects predict their appearance to implement countermeasures.