RÉSUMÉ
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Sujet(s)
Couverture vaccinale , Rappel de vaccinRÉSUMÉ
Glycoconjugate vaccines elicit robust anti-polysaccharide Ab response by recruiting T-cell help. Multiple doses of glycoconjugate vaccine are required to induce long-lasting immunity. The characteristics of anti-polysaccharide Ab response have been reported previously. However, the effect of glycoconjugate booster immunization on anti-polysaccharide and anti-carrier protein Ab repertoire remains poorly understood. In this study, we used clinically relevant pneumococcal capsular polysaccharide type 14 (PCP14) conjugated with cross-reactive material 197 (CRM197) as a model glycoconjugate Ag (PCP14-CRM197). We performed a comprehensive sequence analysis of mouse mAbs generated against PCP14 and CRM197 following immunization with one or three doses of PCP14-CRM197. Analysis of the paired Ig H and L chain transcripts revealed that anti-PCP14 Ab repertoire is extremely restricted. The reoccurrence of five replacement mutations at identical positions in anti-polysaccharide mAbs generated from different mice provided evidence for Ag-driven selection in PCP14-specific B cells. Convergent evolution was observed wherein distinct V(D)J rearrangements resulted in identical or nearly identical CDR3 in anti-PCP14 mAbs. Abs that lacked DH encoded amino acids dominated the anti-PCP14 Ab response. In contrast, anti-CRM197 Ab response was quite diverse, with fewer mutations compared with the anti-PCP14 mAbs, suggesting that conjugation of the polysaccharide to a carrier protein interferes with the development of carrier protein-specific Ab responses. Our findings provide molecular insights into the maturation of Ab responses driven by booster doses of glycoconjugate. This has fundamental implications for the design of glycoconjugate vaccines, especially where the development of Ab response against the carrier protein is also crucial.
Sujet(s)
Anticorps antibactériens , Lymphocytes B , Protéines bactériennes , Glycoconjugués , Animaux , Souris , Glycoconjugués/immunologie , Lymphocytes B/immunologie , Protéines bactériennes/immunologie , Protéines bactériennes/génétique , Anticorps antibactériens/immunologie , Anticorps monoclonaux/immunologie , Vaccins conjugués/immunologie , Vaccins conjugués/administration et posologie , Femelle , Polyosides bactériens/immunologie , Vaccins antipneumococciques/immunologie , Vaccins antipneumococciques/administration et posologie , Streptococcus pneumoniae/immunologie , Souris de lignée BALB C , Antigènes bactériens/immunologie , Immunisation/méthodes , Rappel de vaccinRÉSUMÉ
Vaccine responsiveness is often reduced in older adults. Yet, our lack of understanding of low vaccine responsiveness hampers the development of effective vaccination strategies to reduce the impact of infectious diseases in the ageing population. Young-adult (25-49 y), middle-aged (50-64 y) and older-adult ( ≥ 65 y) participants of the VITAL clinical trials (n = 315, age-range: 28-98 y), were vaccinated with an annual (2019-2020) quadrivalent influenza (QIV) booster vaccine, followed by a primary 13-valent pneumococcal-conjugate (PCV13) vaccine (summer/autumn 2020) and a primary series of two SARS-CoV-2 mRNA-1273 vaccines (spring 2021). This unique setup allowed investigation of humoral responsiveness towards multiple vaccines within the same individuals over the adult age-range. Booster QIV vaccination induced comparable H3N2 hemagglutination inhibition (HI) titers in all age groups, whereas primary PCV13 and mRNA-1273 vaccination induced lower antibody concentrations in older as compared to younger adults (primary endpoint). The persistence of humoral responses, towards the 6 months timepoint, was shorter in older adults for all vaccines (secondary endpoint). Interestingly, highly variable vaccine responder profiles overarching multiple vaccines were observed. Yet, approximately 10% of participants, mainly comprising of older male adults, were classified as low responders to multiple vaccines. This study aids the identification of risk groups for low vaccine responsiveness and hence supports targeted vaccination strategies. Trial number: NL69701.041.19, EudraCT: 2019-000836-24.
Sujet(s)
Vaccin ARNm-1273 contre la COVID-19 , Anticorps antiviraux , COVID-19 , Immunité humorale , Rappel de vaccin , Vaccins antigrippaux , Grippe humaine , Vaccins antipneumococciques , SARS-CoV-2 , Humains , Adulte d'âge moyen , Adulte , Sujet âgé , Mâle , Femelle , Vaccins antigrippaux/immunologie , Vaccins antigrippaux/administration et posologie , Anticorps antiviraux/immunologie , Anticorps antiviraux/sang , Immunité humorale/immunologie , Vaccins antipneumococciques/immunologie , Vaccins antipneumococciques/administration et posologie , COVID-19/prévention et contrôle , COVID-19/immunologie , SARS-CoV-2/immunologie , Sujet âgé de 80 ans ou plus , Vaccin ARNm-1273 contre la COVID-19/immunologie , Grippe humaine/prévention et contrôle , Grippe humaine/immunologie , Facteurs âges , Vaccins contre la COVID-19/immunologie , Vaccins contre la COVID-19/administration et posologie , Sous-type H3N2 du virus de la grippe A/immunologie , Vaccination , Tests d'inhibition de l'hémagglutinationRÉSUMÉ
Objective: This study compared clinical and immunological responses to coinfection challenge of beef calves mucosally primed and differentially boosted with commercial combination vaccines containing antigens against bovine coronavirus (BCoV), bovine parainfluenza virus Type 3 (BPIV3), and bovine respiratory syncytial virus (BRSV). Animals: Nineteen commercial beef heifers. Procedure: At birth, calves were mucosally (IN) primed with modified-live virus (MLV) vaccines, differentially boosted by injection of either combination MLV (IN-MLV) or inactivated virus (IN-KV) vaccines at a mean age of 44 d, and then challenged by coinfection with BCoV, BPIV3, and BRSV at weaning. Results: Both groups were similarly protected from clinical disease and had anamnestic neutralizing antibody responses to all 3 viruses. The IN-KV group shed more BCoV, and less BPIV3 and BRSV, than the IN-MLV group. Conclusion: These data indicated similar clinical and immunological protection between IN-MLV and IN-KV; however, shed of virus varied. Clinical relevance: Whereas boosting with KV or MLV appeared to have similar efficacy, viral shed differences may affect disease control.
Efficacité comparative des vaccins vivants modifiés et inactivés pour stimuler les réponses au virus respiratoire syncytial bovin, au virus parainfluenza bovin de type 3 et au coronavirus bovin après amorçage via la muqueuse de veaux de boucherie nouveau-nés. Objectif: Cette étude a comparé les réponses cliniques et immunologiques à une co-infection de veaux de boucherie amorcés par voie muqueuse et différentiellement stimulés avec des vaccins combinés commerciaux contenant des antigènes contre le coronavirus bovin (BCoV), le virus parainfluenza bovin de type 3 (BPIV3) et le virus respiratoire syncytial bovin (BRSV). Animaux: Dix-neuf génisses de boucherie commerciales. Procédure: À la naissance, les veaux ont été vaccinés au niveau des muqueuses (IN) avec des vaccins à virus vivants modifiés (MLV), stimulés de manière différentielle par l'injection de vaccins combinés MLV (IN-MLV) ou de virus inactivés (IN-KV) à un âge moyen de 44 jours. puis provoqué par une co-infection avec BCoV, BPIV3 et BRSV au sevrage. Résultats: Les deux groupes étaient protégés de la même manière contre la maladie clinique et présentaient des réponses anamnestiques en anticorps neutralisants contre les 3 virus. Le groupe IN-KV a excrété plus de BCoV et moins de BPIV3 et de BRSV que le groupe IN-MLV. Conclusion: Ces données indiquent une protection clinique et immunologique similaire entre IN-MLV et IN-KV; cependant, l'excrétion du virus variait. Pertinence clinique: Alors que le rappel avec KV ou MLV semble avoir une efficacité similaire, les différences d'excrétion virale peuvent affecter la limitation de la maladie.(Traduit par Dr Serge Messier).
Sujet(s)
Animaux nouveau-nés , Maladies des bovins , Coronavirus bovin , Virus parainfluenza bovin de type 3 , Infections à virus respiratoire syncytial , Virus respiratoire syncytial bovin , Vaccins inactivés , Vaccins antiviraux , Animaux , Bovins , Coronavirus bovin/immunologie , Virus parainfluenza bovin de type 3/immunologie , Virus respiratoire syncytial bovin/immunologie , Maladies des bovins/prévention et contrôle , Maladies des bovins/virologie , Maladies des bovins/immunologie , Femelle , Vaccins inactivés/immunologie , Vaccins inactivés/administration et posologie , Infections à virus respiratoire syncytial/médecine vétérinaire , Infections à virus respiratoire syncytial/prévention et contrôle , Infections à virus respiratoire syncytial/immunologie , Vaccins antiviraux/immunologie , Vaccins antiviraux/administration et posologie , Animaux nouveau-nés/immunologie , Infections à coronavirus/médecine vétérinaire , Infections à coronavirus/prévention et contrôle , Infections à coronavirus/immunologie , Infections à coronavirus/virologie , Anticorps antiviraux/sang , Vaccins atténués/immunologie , Vaccins atténués/administration et posologie , Infections à respirovirus/médecine vétérinaire , Infections à respirovirus/prévention et contrôle , Infections à respirovirus/immunologie , Rappel de vaccin/médecine vétérinaireRÉSUMÉ
BACKGROUND: Data on the dynamics and persistence of humoral immunity against SARS-CoV-2 after primary vaccination with two-dose inactivated vaccine (CoronaVac) are limited. This study evaluated the sequential effects of prior infection, heterologous boosting with mRNA-1273 (Moderna), and the occurrence of Omicron vaccine-breakthrough infection (VBI) thereafter. METHODS: We evaluated anti-spike IgG (Abbott) and neutralising (cPASS/GenScript) antibody (nAb) titers up to one year after mRNA-1273 boost in two-dose-CoronaVac-primed Indonesian healthcare workers (August 2021-August 2022). We used linear mixed modeling to estimate the rate of change in antibody levels, and logistic regression to examine associations between antibody levels and VBI. RESULTS: Of 138 participants, 52 (37.7%) had a prior infection and 78 (56.5%) received an mRNA-1273 booster. After two-dose CoronaVac, antibody titers had significantly declined within 180 days, irrespective of prior infection. After mRNA-1273 booster, anti-spike IgG (1.47% decline/day) and Omicron B.1.1.529/BA.2 nAbs declined between day 28-90, and IgG titers plateaued between day 90-360. During the BA.1/BA.2 wave (February-March 2022), 34.6% (27/78) of individuals experienced a VBI (median 181 days after mRNA-1273), although none developed severe illness. VBI was associated with low pre-VBI anti-spike IgG and B.1.1.529/BA.2 nAbs, which were restored post-VBI. CONCLUSIONS: mRNA-1273 booster after two-dose CoronaVac did not prevent BA.1/BA.2 VBI. Periodic vaccine boosters may be warranted against emerging SARS-CoV-2 variants.
Sujet(s)
Vaccin ARNm-1273 contre la COVID-19 , Anticorps neutralisants , Anticorps antiviraux , Réinfections , Vaccins contre la COVID-19 , COVID-19 , Rappel de vaccin , SARS-CoV-2 , Adulte , Femelle , Humains , Mâle , Adulte d'âge moyen , Vaccin ARNm-1273 contre la COVID-19/immunologie , Vaccin ARNm-1273 contre la COVID-19/administration et posologie , Anticorps neutralisants/sang , Anticorps neutralisants/immunologie , Anticorps antiviraux/sang , Anticorps antiviraux/immunologie , Réinfections/épidémiologie , Réinfections/immunologie , Réinfections/prévention et contrôle , COVID-19/prévention et contrôle , COVID-19/immunologie , COVID-19/épidémiologie , Vaccins contre la COVID-19/immunologie , Vaccins contre la COVID-19/administration et posologie , Personnel de santé , Immunoglobuline G/sang , Indonésie/épidémiologie , SARS-CoV-2/immunologie , Glycoprotéine de spicule des coronavirus/immunologie , Vaccination , Vaccins inactivés/immunologie , Vaccins inactivés/administration et posologieRÉSUMÉ
BACKGROUND: Electronic informed consent (eConsent) usage has expanded in recent years in Europe, especially during the pandemic. Slow recruitment rate and limitations in participant outreach are the challenges often faced in clinical research. Given the benefits of eConsent and group counselling reported in the literature, group eConsent was implemented in recruitment for the SWITCH-ON study. We aim to explore the experience of participants who attended group eConsent for the SWITCH-ON study and evaluate its potential for future use. METHODS: SWITCH-ON study aims to analyse the immunogenicity of a healthy population following bivalent COVID-19 booster vaccination. Four hundred thirty-four healthcare workers aged 18-65 were successfully recruited and sent a questionnaire about their experience with group eConsent. Out of 399 completed questionnaires (response rate 92%), 39 participants did not join group eConsent. The remaining 360 responses were included in the final analysis. Quantitative and qualitative data were reported using descriptive statistical analysis and thematic analysis respectively. RESULTS: Participants found that group eConsent was an efficient method that it allowed them to hear each other's questions and concerns and created a sense of togetherness. However, limited privacy, barriers to asking questions in a group, and peer pressure can limit the use of group eConsent. One hundred sixty-five (46%) participants thought that group eConsent was suitable to recruit participants with diseases or conditions, while 87 (24%) reported limitations with this method. The remaining participants suggested that applicability of group eConsent depended on the diseases or conditions of the study population, and one-to-one conversation should always be available. Participants who had experienced both one-to-one and group eConsent shared different preferred consent formats for future studies. CONCLUSION: Group eConsent was positively evaluated by the participants of a low-risk vaccination study. Participants advised using webinars to provide general information about the study, followed by an individual session for each participant, would retain the benefits of group eConsent and minimise the limitations it posed. This proposed setting addresses privacy questions and makes group eConsent easier to implement. TRIAL REGISTRATION: ClinicalTrials.gov NCT05471440 (registered on 22nd of July, 2022).
Sujet(s)
Vaccins contre la COVID-19 , COVID-19 , Consentement libre et éclairé , Humains , Adulte , Adulte d'âge moyen , Mâle , Femelle , COVID-19/prévention et contrôle , Jeune adulte , Adolescent , Vaccins contre la COVID-19/administration et posologie , Sujet âgé , Enquêtes et questionnaires , SARS-CoV-2/immunologie , Vaccination , Rappel de vaccin , CommunicationRÉSUMÉ
Live-attenuated influenza vaccines (LAIV) offer advantages over the commonly used inactivated split influenza vaccines. However, finding the optimal balance between sufficient attenuation and immunogenicity has remained a challenge. We recently developed an alternative LAIV based on the 2009 pandemic H1N1 virus with a truncated NS1 protein and lacking PA-X protein expression (NS1(1-126)-ΔPAX). This virus showed a blunted replication and elicited a strong innate immune response. In the present study, we evaluated the efficacy of this vaccine candidate in the porcine animal model as a pertinent in vivo system. Immunization of pigs via the nasal route with the novel NS1(1-126)-ΔPAX LAIV did not cause disease and elicited a strong mucosal immune response that completely blocked replication of the homologous challenge virus in the respiratory tract. However, we observed prolonged shedding of our vaccine candidate from the upper respiratory tract. To improve LAIV safety, we developed a novel prime/boost vaccination strategy combining primary intramuscular immunization with a haemagglutinin-encoding propagation-defective vesicular stomatitis virus (VSV) replicon, followed by a secondary immunization with the NS1(1-126)-ΔPAX LAIV via the nasal route. This two-step immunization procedure significantly reduced LAIV shedding, increased the production of specific serum IgG, neutralizing antibodies, and Th1 memory cells, and resulted in sterilizing immunity against homologous virus challenge. In conclusion, our novel intramuscular prime/intranasal boost regimen interferes with virus shedding and transmission, a feature that will help combat influenza epidemics and pandemics.
Sujet(s)
Administration par voie nasale , Vaccins antigrippaux , Infections à Orthomyxoviridae , Animaux , Suidae , Vaccins antigrippaux/immunologie , Vaccins antigrippaux/administration et posologie , Infections à Orthomyxoviridae/prévention et contrôle , Infections à Orthomyxoviridae/immunologie , Injections musculaires , Vaccins atténués/immunologie , Vaccins atténués/administration et posologie , Sous-type H1N1 du virus de la grippe A/immunologie , Modèles animaux de maladie humaine , Anticorps antiviraux/immunologie , Rappel de vaccin/méthodes , Vaccination/méthodes , Grippe humaine/prévention et contrôle , Grippe humaine/immunologieRÉSUMÉ
The rapid development of vaccines against SARS-CoV-2 altered the course of the COVID-19 pandemic. In most countries, vaccinations were initially targeted at high-risk populations, including older individuals and healthcare workers. Now, despite substantial infection- and vaccine-induced immunity in host populations worldwide, waning immunity and the emergence of novel variants continue to cause significant waves of infection and disease. Policy makers must determine how to deploy booster vaccinations, particularly when constraints in vaccine supply, delivery and cost mean that booster vaccines cannot be administered to everyone. A key question is therefore whether older individuals should again be prioritised for vaccination, or whether alternative strategies (e.g. offering booster vaccines to the individuals who have most contacts with others and therefore drive infection) can instead offer indirect protection to older individuals. Here, we use mathematical modelling to address this question, considering SARS-CoV-2 transmission in a range of countries with different socio-economic backgrounds. We show that the population structures of different countries can have a pronounced effect on the impact of booster vaccination, even when identical booster vaccination targeting strategies are adopted. However, under the assumed transmission model, prioritising older individuals for booster vaccination consistently leads to the most favourable public health outcomes in every setting considered. This remains true for a range of assumptions about booster vaccine supply and timing, and for different assumed policy objectives of booster vaccination.
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Vaccins contre la COVID-19 , COVID-19 , Rappel de vaccin , Santé publique , SARS-CoV-2 , Humains , COVID-19/prévention et contrôle , COVID-19/épidémiologie , Rappel de vaccin/statistiques et données numériques , Vaccins contre la COVID-19/administration et posologie , Vaccins contre la COVID-19/immunologie , Sujet âgé , SARS-CoV-2/immunologie , Facteurs socioéconomiques , Adulte d'âge moyen , Vaccination/statistiques et données numériques , Pandémies/prévention et contrôleRÉSUMÉ
Purpose: Heterologous immunization using different vaccine platforms has been demonstrated as an efficient strategy to enhance antigen-specific immune responses. In this study, we performed a head-to-head comparison of both humoral and cellular immune response induced by different prime-boost immunization regimens of mRNA vaccine and adjuvanted protein subunit vaccine against varicella-zoster virus (VZV) in middle-aged mice, aiming to get a better understanding of the influence of vaccination schedule on immune response. Methods: VZV glycoprotein (gE) mRNA was synthesized and encapsulated into SM-102-based lipid nanoparticles (LNPs). VZV-primed middle-aged C57BL/6 mice were then subjected to homologous and heterologous prime-boost immunization strategies using VZV gE mRNA vaccine (RNA-gE) and protein subunit vaccine (PS-gE). The antigen-specific antibodies were evaluated using enzyme-linked immunosorbent assay (ELISA) analysis. Additionally, cell-mediated immunity (CMI) was detected using ELISPOT assay and flow cytometry. Besides, in vivo safety profiles were also evaluated and compared. Results: The mRNA-loaded lipid nanoparticles had a hydrodynamic diameter of approximately 130 nm and a polydispersity index of 0.156. Total IgG antibody levels exhibited no significant differences among different immunization strategies. However, mice received 2×RNA-gE or RNA-gE>PS-gE showed a lower IgG1/IgG2c ratio than those received 2×PS-gE and PS-gE> RNA-gE. The CMI response induced by 2×RNA-gE or RNA-gE>PS-gE was significantly stronger than that induced by 2×PS-gE and PS-gE> RNA-gE. The safety evaluation indicated that both mRNA vaccine and protein vaccine induced a transient body weight loss in mice. Furthermore, the protein vaccine produced a notable inflammatory response at the injection sites, while the mRNA vaccine showed no observable inflammation. Conclusion: The heterologous prime-boost strategy has demonstrated that an mRNA-primed immunization regimen can induce a better cell-mediated immune response than a protein subunit-primed regimen in middle-aged mice. These findings provide valuable insights into the design and optimization of VZV vaccines with the potentials to broaden varicella vaccination strategies in the future.
Sujet(s)
Adjuvants immunologiques , Immunité cellulaire , Souris de lignée C57BL , Nanoparticules , Vaccins sous-unitaires , Animaux , Vaccins sous-unitaires/immunologie , Vaccins sous-unitaires/administration et posologie , Nanoparticules/composition chimique , Adjuvants immunologiques/administration et posologie , Femelle , Vaccins à ARNm , Souris , Herpèsvirus humain de type 3/immunologie , Anticorps antiviraux/sang , Rappel de vaccin/méthodes , Protéines de l'enveloppe virale/immunologie , Protéines de l'enveloppe virale/administration et posologie , Vaccin contre le zona/immunologie , Vaccin contre le zona/administration et posologie , LiposomesRÉSUMÉ
Objective: to evaluate the immune response to the SARS-CoV-2 vaccines in adults with immune-mediated rheumatic diseases (IMRDs) in comparison to healthy individuals, observed 1-20 weeks following the fourth vaccine dose. Additionally, to evaluate the impact of immunosuppressive therapies, vaccination schedules, the time interval between vaccination and sample collection on the vaccine's immune response. Methods: We designed a longitudinal observational study conducted at the rheumatology department of Hospital de Copiapó. Neutralizing antibodies (Nabs) titers against the Wuhan and Omicron variant were analyzed between 1-20 weeks after administration of the fourth dose of the SARS-CoV-2 vaccine to 341 participants (218 IMRD patients and 123 healthy controls). 218 IMRD patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), systemic lupus erythematosus (SLE), systemic vasculitis (VS) and systemic scleroderma (SS) were analyzed. Results: Performing a comparison between the variants, Wuhan vs Omicron, we noticed that there were significant differences (p<0.05) in the level of the ID50, both for healthy controls and for patients with IMRDs. The humoral response of patients with IMRDs is significantly lower compared to healthy controls for the Omicron variant of SARS-CoV-2 (p = 0.0015). The humoral response of patients with IMRDs decreases significantly when the time interval between vaccination and sample collection is greater than 35 days. This difference was observed in the response, both for the Wuhan variant and for the Omicron variant. Conclusion: The IMRDs patients, the humoral response variation in the SARS-CoV-2 vaccine depends on doses and type of vaccine administered, the humoral response times and the treatment that these patients are receiving.
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Anticorps neutralisants , Anticorps antiviraux , Vaccins contre la COVID-19 , COVID-19 , Rappel de vaccin , Rhumatismes , SARS-CoV-2 , Humains , Mâle , Adulte d'âge moyen , Femelle , COVID-19/immunologie , COVID-19/prévention et contrôle , SARS-CoV-2/immunologie , Vaccins contre la COVID-19/immunologie , Vaccins contre la COVID-19/administration et posologie , Anticorps neutralisants/sang , Anticorps neutralisants/immunologie , Rhumatismes/immunologie , Anticorps antiviraux/sang , Anticorps antiviraux/immunologie , Adulte , Sujet âgé , Études longitudinales , VaccinationSujet(s)
Anticorps neutralisants , Anticorps neutralisants/immunologie , Humains , Vaccins synthétiques/immunologie , Vaccins synthétiques/génétique , Rappel de vaccin , Protéines recombinantes/immunologie , Protéines recombinantes/génétique , SARS-CoV-2/immunologie , SARS-CoV-2/génétique , Animaux , Anticorps antiviraux/immunologie , COVID-19/immunologie , COVID-19/prévention et contrôleRÉSUMÉ
AIM: The study aimed to compare long-term vaccine-induced humoral immunity following different vaccines regimens. METHODS: Anti-S-RBD total antibody levels were measured in blood samples of 167 participants nearly 6 months post-vaccination. Participants had received one; two or four doses of Pfizer vaccine or who received a third dose of mRNA vaccine (Pfizer) and primed with mRNA (Pfizer/Moderna), adenoviral (AstraZeneca/Jonson & Jonson) or inactivated (CoronaVac/Sinopharm) vaccine. RESULTS: Among all vaccination regimens, fourth dose of Pfizer achieved the highest S-RBD antibody titers. Nevertheless, the third dose of mRNA vaccine primed with adenoviral vaccine achieved the lowest titers of S-RBD antibody. Notably, the group that received a third dose of mRNA primed with two doses of mRNA vaccine exhibited higher S-RBD antibody compared to groups inoculated with a third dose of mRNA and primed with inactivated or adenovirus vaccine. CONCLUSION: Our data showed the superiority of three mRNA vaccinations compared to third heterologous vaccine (inactivated of adenoviral) including mRNA as booster in terms of humoral immunogenicity. Our findings supporting the use of additional booster shot from a more potent vaccine type such as mRNA vaccines. Nevertheless, due to the limited number of subjects, it is difficult to extrapolate the results of our study to the whole of Tunisian population. Future studies should investigate a larger cohort and other potential correlates of protection, such as cellular immunity and how it is affected by different vaccination schemes after long-term post-vaccination.
Sujet(s)
Anticorps antiviraux , Vaccins contre la COVID-19 , COVID-19 , SARS-CoV-2 , Humains , Tunisie , Anticorps antiviraux/sang , Anticorps antiviraux/immunologie , Mâle , Femelle , Adulte , COVID-19/prévention et contrôle , COVID-19/immunologie , Adulte d'âge moyen , Vaccins contre la COVID-19/immunologie , Vaccins contre la COVID-19/administration et posologie , SARS-CoV-2/immunologie , Vaccination/méthodes , Rappel de vaccin/méthodes , Immunité humorale/immunologie , Glycoprotéine de spicule des coronavirus/immunologie , Vaccins inactivés/immunologie , Vaccins inactivés/administration et posologie , Vaccins à ARNm/immunologieRÉSUMÉ
COVID-19 vaccines have been illustrated to lessen the growth of sickness caused by the virus effectively. In any case, inoculation has consistently been controversial, with differing opinions and viewpoints. This has compelled some individuals to decide against receiving the vaccine. These divergent viewpoints have had a trivial impact on the epidemic's dynamics and the disease's development. In response to vaccinated individuals still falling ill, many countries have implemented booster vaccines to protect further. In this specific investigation, a mathematical model composed of seven compartments is employed to examine the effectiveness of a booster dose in preventing and treating the transmission of COVID-19. The principles of mathematics are employed to analyse and investigate the dynamics of the disease. Using a qualitative prototype analysis, we acquired valuable insights into its effectiveness. One essential aspect is the basic reproduction number, a critical determinant of the disease's spread. This calculation is determined by studying the system's equilibrium and evaluating its stability. Furthermore, we examined the balance from a local and global viewpoint, considering the possibility of bifurcation and the model's reproductive number sensitivity index. Through numerical simulations, we have visually illustrated the analytical findings outlined in this research paper and presented a thorough examination of the efficacy of booster shots as a preventive and therapeutic measure in the spread dynamics of COVID-19.
Sujet(s)
Vaccins contre la COVID-19 , COVID-19 , Rappel de vaccin , SARS-CoV-2 , Humains , COVID-19/prévention et contrôle , COVID-19/épidémiologie , Vaccins contre la COVID-19/administration et posologie , Vaccins contre la COVID-19/immunologie , SARS-CoV-2/immunologie , Taux de reproduction de base , Vaccination/méthodes , Modèles théoriques , Simulation numériqueRÉSUMÉ
BACKGROUND: SARS-CoV-2 vaccines are safe and effective against infection and severe COVID-19 disease worldwide. Certain co-morbid conditions cause immune dysfunction and may reduce immune response to vaccination. In contrast, those with co-morbidities may practice infection prevention strategies. Thus, the real-world clinical impact of co-morbidities on SARS-CoV-2 infection in the recent post-vaccination period is not well established. This study was performed to understand the epidemiology of Omicron breakthrough infection and evaluate associations with number of comorbidities in a vaccinated and boosted population. METHODS AND FINDINGS: A retrospective clinical cohort study was performed utilizing the Northwestern Medicine Enterprise Data Warehouse. Our study population was identified as fully vaccinated adults with at least one booster. The primary risk factor of interest was the number of co-morbidities. The primary outcome was the incidence and time to the first positive SARS-CoV-2 molecular test in the Omicron predominant era. Multivariable Cox modeling analyses to determine the hazard of SARS-CoV-2 infection were stratified by calendar time (Period 1: January 1 -June 30, 2022; Period 2: July 1 -December 31, 2022) due to violations in the proportional hazards assumption. In total, 133,191 patients were analyzed. During Period 1, having 3+ comorbidities was associated with increased hazard for breakthrough (HR = 1.16 CI 1.08-1.26). During Period 2 of the study, having 2 comorbidities (HR = 1.45 95% CI 1.26-1.67) and having 3+ comorbidities (HR 1.73, 95% CI 1.51-1.97) were associated with increased hazard for Omicron breakthrough. Older age was associated with decreased hazard in Period 1 of follow-up. Interaction terms for calendar time indicated significant changes in hazard for many factors between the first and second halves of the follow-up period. CONCLUSIONS: Omicron breakthrough is common with significantly higher risk for our most vulnerable patients with multiple co-morbidities. Age plays an important role in breakthrough infection with the highest incidence among young adults, which may be due to age-related behavioral factors. These findings reflect real-world differences in immunity and exposure risk behaviors for populations vulnerable to COVID-19.
Sujet(s)
Vaccins contre la COVID-19 , COVID-19 , SARS-CoV-2 , Humains , COVID-19/épidémiologie , COVID-19/prévention et contrôle , COVID-19/virologie , Mâle , Femelle , Adulte d'âge moyen , SARS-CoV-2/immunologie , Incidence , Facteurs de risque , Adulte , Études rétrospectives , Vaccins contre la COVID-19/immunologie , Sujet âgé , Chicago/épidémiologie , Comorbidité , Vaccination , Rappel de vaccin , Jeune adulte , RéinfectionsRÉSUMÉ
BACKGROUND: Mutations present in emerging SARS-CoV-2 variants permit evasion of neutralization with prototype vaccines. A novel Omicron BA.1 subvariant-specific vaccine (NVX-CoV2515) was tested alone or as a bivalent preparation with the prototype vaccine (NVX-CoV2373) to assess antibody responses to SARS-CoV-2. METHODS: Participants aged 18 to 64 years immunized with 3 doses of prototype mRNA vaccines were randomized 1:1:1 to receive a single dose of NVX-CoV2515, NVX-CoV2373, or the bivalent mixture in a phase 3 study investigating heterologous boosting with SARS-CoV-2 recombinant spike protein vaccines. Immunogenicity was measured 14 and 28 days after vaccination for the SARS-CoV-2 Omicron BA.1 sublineage and ancestral strain. Safety profiles of vaccines were assessed. RESULTS: Of participants who received trial vaccine (N = 829), those administered NVX-CoV2515 (n = 286) demonstrated a superior neutralizing antibody response to BA.1 vs NVX-CoV2373 (n = 274) at day 14 (geometric mean titer ratio, 1.6; 95% CI, 1.33-2.03). Seroresponse rates were 73.4% (91/124; 95% CI, 64.7-80.9) for NVX-CoV2515 vs 50.9% (59/116; 95% CI, 41.4-60.3) for NVX-CoV2373. All formulations were similarly well tolerated. CONCLUSIONS: NVX-CoV2515 elicited a superior neutralizing antibody response against the Omicron BA.1 subvariant as compared with NVX-CoV2373 when administered as a fourth dose. Safety data were consistent with the established safety profile of NVX-CoV2373. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov (NCT05372588).
Sujet(s)
Anticorps neutralisants , Anticorps antiviraux , Vaccins contre la COVID-19 , COVID-19 , Rappel de vaccin , Immunogénicité des vaccins , SARS-CoV-2 , Glycoprotéine de spicule des coronavirus , Humains , Vaccins contre la COVID-19/immunologie , Vaccins contre la COVID-19/administration et posologie , Vaccins contre la COVID-19/effets indésirables , Adulte , SARS-CoV-2/immunologie , SARS-CoV-2/génétique , Anticorps antiviraux/sang , Anticorps antiviraux/immunologie , Glycoprotéine de spicule des coronavirus/immunologie , Glycoprotéine de spicule des coronavirus/génétique , Mâle , Femelle , COVID-19/prévention et contrôle , COVID-19/immunologie , Anticorps neutralisants/sang , Anticorps neutralisants/immunologie , Jeune adulte , Adulte d'âge moyen , Adolescent , Vaccins synthétiques/immunologie , Vaccins synthétiques/administration et posologie , Vaccins synthétiques/effets indésirablesRÉSUMÉ
An upcoming trial may provide further evidence that adolescent/adult-targeted BCG revaccination prevents sustained Mycobacterium tuberculosis infection, but its public health value depends on its impact on overall tuberculosis morbidity and mortality, which will remain unknown. Using previously calibrated models for India and South Africa, we simulated BCG revaccination assuming 45% prevention-of-infection efficacy, and we evaluated scenarios varying additional prevention-of-disease efficacy between +50% (reducing risk) and -50% (increasing risk). Given the assumed prevention-of-infection efficacy and range in prevention-of-disease efficacy, BCG revaccination may have a positive health impact and be cost-effective. This may be useful when considering future evaluations and implementation of adolescent/adult BCG revaccination.
Sujet(s)
Vaccin BCG , Rappel de vaccin , Santé publique , Tuberculose , Humains , Tuberculose/prévention et contrôle , Tuberculose/épidémiologie , Vaccin BCG/immunologie , République d'Afrique du Sud/épidémiologie , Adolescent , Inde/épidémiologie , Adulte , Analyse coût-bénéfice , Enfant , Jeune adulte , Nourrisson , Enfant d'âge préscolaire , Mycobacterium tuberculosisSujet(s)
Varicelle , Rappel de vaccin , Humains , Varicelle/virologie , Issue fatale , Herpèsvirus humain de type 3/isolement et purification , Herpèsvirus humain de type 3/génétique , Vaccin contre la varicelle/effets indésirables , Vaccin contre la varicelle/administration et posologie , Vaccin contre la varicelle/immunologie , Mâle , Immunocompétence , Femelle , Enfant d'âge préscolaireRÉSUMÉ
BACKGROUND: Immunocompromised hosts (ICH) experience more breakthrough infections and worse clinical outcomes following infection with COVID-19 than immunocompetent people. Prophylactic monoclonal antibody therapies can be challenging to access, and escape variants emerge rapidly. Immunity conferred through vaccination remains a central prevention strategy for COVID-19. COVID-19 vaccines do not elicit optimal immunity in ICH but boosting, through additional doses of vaccine improves humoral and cellular immune responses. This trial aims to assess the immunogenicity and safety of different COVID-19 vaccine booster strategies against SARS-CoV-2 for ICH in Australia. METHODS: Bringing optimised COVID-19 vaccine schedules to immunocompromised populations (BOOST-IC) is an adaptive randomised trial of one or two additional doses of COVID-19 vaccines 3 months apart in people living with HIV, solid organ transplant (SOT) recipients, or those who have haematological malignancies (chronic lymphocytic leukaemia, non-Hodgkin lymphoma or multiple myeloma). Key eligibility criteria include having received 3 to 7 doses of Australian Therapeutic Goods Administration (TGA)-approved COVID-19 vaccines at least 3 months earlier, and having not received SARS-CoV-2-specific monoclonal antibodies in the 3 months prior to receiving the study vaccine. The primary outcome is the geometric mean concentration of anti-spike SARS-CoV-2 immunoglobulin G (IgG) 28 days after the final dose of the study vaccine. Key secondary outcomes include anti-spike SARS-CoV-2 IgG titres and the proportion of people seroconverting 6 and 12 months after study vaccines, local and systemic reactions in the 7 days after vaccination, adverse events of special interest, COVID-19 infection, mortality and quality of life. DISCUSSION: This study will enhance the understanding of COVID-19 vaccine responses in ICH, and enable the development of safe, and optimised vaccine schedules in people with HIV, SOT, or haematological malignancy. TRIAL REGISTRATION: ClinicalTrials.gov NCT05556720. Registered on 23rd August 2022.
Sujet(s)
Vaccins contre la COVID-19 , COVID-19 , Calendrier vaccinal , Sujet immunodéprimé , SARS-CoV-2 , Humains , COVID-19/prévention et contrôle , COVID-19/immunologie , Vaccins contre la COVID-19/immunologie , Vaccins contre la COVID-19/administration et posologie , Vaccins contre la COVID-19/effets indésirables , SARS-CoV-2/immunologie , Immunogénicité des vaccins , Essais contrôlés randomisés comme sujet , Rappel de vaccin , Australie , Adulte , Facteurs tempsRÉSUMÉ
The long-term association between mRNA-based coronavirus disease 2019 (COVID-19) vaccination and the development of autoimmune connective tissue diseases (AI-CTDs) remains unclear. In this nationwide, population-based cohort study involving 9,258,803 individuals, we aim to determine whether the incidence of AI-CTDs is associated with mRNA vaccination. The study spans over 1 year of observation and further analyses the risk of AI-CTDs by stratifying demographics and vaccination profiles and treating booster vaccination as time-varying covariate. We report that the risk of developing most AI-CTDs did not increase following mRNA vaccination, except for systemic lupus erythematosus with a 1.16-fold risk in vaccinated individuals relative to controls. Comparable results were reported in the stratified analyses for age, sex, mRNA vaccine type, and prior history of non-mRNA vaccination. However, a booster vaccination was associated with an increased risk of some AI-CTDs including alopecia areata, psoriasis, and rheumatoid arthritis. Overall, we conclude that mRNA-based vaccinations are not associated with an increased risk of most AI-CTDs, although further research is needed regarding its potential association with certain conditions.
Sujet(s)
Maladies auto-immunes , Vaccins contre la COVID-19 , COVID-19 , SARS-CoV-2 , Vaccination , Humains , Maladies auto-immunes/épidémiologie , Maladies auto-immunes/génétique , Femelle , Mâle , Adulte d'âge moyen , Adulte , République de Corée/épidémiologie , COVID-19/prévention et contrôle , COVID-19/épidémiologie , Vaccins contre la COVID-19/effets indésirables , Vaccins contre la COVID-19/immunologie , Vaccins contre la COVID-19/administration et posologie , Études de cohortes , SARS-CoV-2/immunologie , SARS-CoV-2/génétique , Sujet âgé , Jeune adulte , Incidence , Adolescent , Maladies du tissu conjonctif/génétique , Maladies du tissu conjonctif/épidémiologie , Vaccins à ARNm , Rappel de vaccinRÉSUMÉ
BACKGROUND: Updating vaccines is essential for combatting emerging coronavirus disease 2019 (COVID-19) variants. This study assessed the public health and economic impact of a booster dose of an adapted vaccine in the United Kingdom (UK). METHODS: A Markov-decision tree model estimated the outcomes of vaccination strategies targeting various age and risk groups in the UK. Age-specific data derived from published sources were used. The model estimated case numbers, deaths, hospitalizations, medical costs, and societal costs. Scenario analyses were conducted to explore uncertainty. RESULTS: Vaccination targeting individuals aged ≥ 65 years and the high-risk population aged 12-64 years was estimated to avert 701,549 symptomatic cases, 5,599 deaths, 18,086 hospitalizations, 56,326 post-COVID condition cases, and 38,263 lost quality-adjusted life years (QALYs), translating into direct and societal cost savings of £112,174,054 and £542,758,682, respectively. The estimated economically justifiable price at willingness-to-pay thresholds of £20,000 and £30,000 per QALY was £43 and £61, respectively, from the payer perspective and £64 and £82, respectively, from the societal perspective. Expanding to additional age groups improved the public health impact. CONCLUSIONS: Targeting individuals aged ≥ 65 years and those aged 12-64 years at high risk yields public health gains, but expansion to additional age groups provides additional gains.