Covid19-Sources

As a complement to vaccines, small-molecule therapeutic agents are needed to treat or prevent infections by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its variants, which cause COVID-19. Affinity selection-mass spectrometry was used for the discovery of botanical ligands to the …

DMZ – FORSCHUNG ¦ Anton Aeberhard ¦ Cambridge, Massachusetts - Im September 2023 hat Moderna, Inc. (NASDAQ: MRNA) klinische Studiendaten aus ihrem Forschungsassay veröffentlicht, die eine vielversprechende Immunantwort auf die BA.2.86-Variante des Covid-19-Virus zeigen. Diese bahnbrechenden Erkenntnisse könnten entscheidend für die kommende Herbstsaison sein, da die BA.2.86-Variante, auch bekannt als "Pirola", besorgniserregende Eigenschaften aufweist. Die BA.2.86-Variante: Eine besorgniserregende Entwicklung Die Centers for Disease Control (CDC) haben darauf hingewiesen, dass die BA.2.86-Variante möglicherweise besser in der Lage ist, Immunität von früheren Impfungen oder Infektionen zu überwinden. Dies hat weltweit Gesundheitsbehörden alarmiert und die Dringlichkeit unterstrichen, effektive Gegenmaßnahmen zu ergreifen. Modernas Aktualisierung des Covid-19-Impfstoffs Die jüngsten Daten zeigen, dass Modernas aktualisierter Covid-19-Impfstoff eine beeindruckende Immunantwort hervorruft. Menschen, die diesen Impfstoff erhalten, zeigten eine 8,7- bis 11-fache Zunahme neutralisierender Antikörper gegenüber verschiedenen zirkulierenden Varianten, einschließlich BA.2.86, EG.5 und FL.1.5.1. Dies könnte eine entscheidende Waffe im Kampf gegen die BA.2.86-Variante darstellen. Der Weg nach vorne Moderna hat diese vielversprechenden Ergebnisse umgehend mit den Regulierungsbehörden geteilt und wartet nun auf die behördliche Genehmigung für ihren aktualisierten Covid-19-Impfstoff. Die BA.2.86-Variante wird weiterhin aufmerksam beobachtet, da sie über 30 Mutationen im Vergleich zu früheren Omikron-Stämmen aufweist und die Möglichkeit birgt, die Immunität von Personen, die zuvor Covid-19 hatten oder geimpft wurden, zu umgehen. Stephen Hoge, M.D., Präsident von Moderna, betonte die Bedeutung dieser Ergebnisse: "Diese Ergebnisse zeigen, dass unser aktualisierter Covid-19-Impfstoff eine starke Immunantwort gegen die stark mutierte BA.2.86-Variante hervorruft. Zusammen mit unseren zuvor kommunizierten Ergebnissen, die eine ebenso effektive Reaktion gegen die Varianten EG.5 und FL.1.5.1 zeigen, bestätigen diese Daten, dass unser aktualisierter Covid-19-Impfstoff auch weiterhin ein wichtiges Instrument zum Schutz darstellt, wenn wir in die Herbst-Impfsaison gehen." Die Dringlichkeit der Impfung Das Auftreten der BA.2.86-Variante, in Verbindung mit anderen besorgniserregenden Varianten wie EG.5 und FL1.5.1, macht die Impfung mit einem aktualisierten Covid-19-Impfstoff zu einer dringenden Notwendigkeit. Die Daten deuten darauf hin, dass dieser Impfstoff wirksam sein kann, um schwere Krankheiten und Krankenhausaufenthalte durch die derzeit zirkulierenden Varianten zu reduzieren. Moderna hat die klinischen Studiendaten zur Wirksamkeit ihres aktualisierten Covid-19-Impfstoffs gegen die BA.2.86-Variante bei den Regulierungsbehörden eingereicht und plant, diese auch in wissenschaftlichen Fachzeitschriften zu veröffentlichen. Über Moderna Moderna, Inc. hat sich in den letzten zehn Jahren von einem Forschungsunternehmen, das sich auf die Entwicklung von Boten-RNA (mRNA)-basierten Therapien konzentrierte, zu einem führenden Unternehmen in der Impfstoff- und Therapeutikaindustrie entwickelt. Moderna verfügt über ein breites Portfolio von Impfstoffen und Therapeutika in sieben verschiedenen Modalitäten und hat sich auf die schnelle Produktion von mRNA-basierten Produkten spezialisiert. Dies ermöglichte die rasche Entwicklung und Zulassung eines der wirksamsten Impfstoffe gegen die Covid-19-Pandemie. Die mRNA-Plattform von Moderna hat bereits innovative Lösungen für Infektionskrankheiten, Krebstherapie, seltene Erkrankungen und mehr hervorgebracht. Das Unternehmen bleibt bestrebt, die globale öffentliche Gesundheit zu schützen und weiterhin wissenschaftliche Fortschritte im Kampf gegen Covid-19 zu erzielen. Wichtige Sicherheitshinweise Moderna weist darauf hin, dass der Impfstoff nicht an Personen mit bekannten schweren allergischen Reaktionen gegenüber einem seiner Bestandteile verabreicht werden sollte. In Fällen akuter anaphylaktischer Reaktionen nach der Impfung muss sofortige medizinische Behandlung verfügbar sein. Die Post-Marketing-Daten deuten auf ein erhöhtes Risiko für Myokarditis und Perikarditis hin, insbesondere innerhalb von 7 Tagen nach der zweiten Dosis der Primärserie oder der ersten Auffrischungsdosis. Es ist wichtig zu beachten, dass Ohnmachtsanfälle nach der Impfung auftreten können, und daher sollten angemessene Maßnahmen ergriffen werden, um Verletzungen zu verhindern. Für immungeschwächte Personen, einschließlich derjenigen, die immunsuppressive Therapien erhalten, kann die Immunantwort auf den Impfstoff verringert sein. Es besteht keine Garantie dafür, dass der Impfstoff alle geimpften Personen vor Covid-19 schützt. Ausblick Die aktuellen Ergebnisse von Moderna sind vielversprechend und könnten eine entscheidende Rolle in der Bekämpfung von Covid-19 und seinen Varianten spielen. Die Welt wartet gespannt auf die behördliche Genehmigung und die breite Verteilung des aktualisierten Impfstoffs, um die öffentliche Gesundheit zu schützen und die Pandemie einzudämmen.

At a recent medical gathering, researchers presented their latest hypotheses about what causes – and what could treat – the lingering disease.

We find that BA.2.86 has low infectivity in 293T-ACE2 cells, similar to @yunlong_cao results, but high infectivity in CaLu-3 cells - actually the highest among all Omicron variants tested. pic.twitter.com/rqG19EmEwQ— Shan-Lu Liu (@ShanLuLiu1) September 11, 2023

Different cell types, different results. Two studies now find that in HEK293T cells, BA.2.86 easily has the worst infectivity of all Omicrons. But @ShanLuLiu1 has the 1st results in CaLu-3 cells. found BA.2.86 had by far the highest infectivity of all Omicrons. ¯\_(ツ)_/¯ https://t.co/HLCjuyJJcX— Ryan Hisner (@LongDesertTrain) September 11, 2023

This article reviews the application of the human airway Calu-3 cell line as a respiratory model for studying the effects of gas concentrations, exposure time, biophysical stress, and biological agents on human airway epithelial cells. Calu-3 cells are ...

United States’ jurisdictions implemented varied policies to slow SARS-CoV-2 transmission. Understanding patterns of these policies alongside individual’s behaviors can inform effective outbreak response. To do so, we estimated the time-varying reproduction number (Rt), a weekly measure of real-time transmission using US COVID-19 cases from September 2020-November 2021. We then assessed the association between Rt and policies, personal COVID-19 mitigation behaviors, variants, immunity, and social vulnerability indicators using two multi-level regression models. First, we fit a model with state-level policy stringency according to the Oxford Stringency Index, a composite indicator reflecting the strictness of COVID-19 policies and strength of pandemic-related communication. Our second model included a subset of specific policies. We found that personal mitigation behaviors and vaccination were more strongly associated with decreased transmission than policies. Importantly, transmission was reduced not by a single measure, but by various layered measures. These results underscore the need for policy, behavior change, and risk communication integration to reduce virus transmission during epidemics. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: All data are available in the main text or the supplementary materials. COVID-19 case data are available upon request at https://data.cdc.gov/Case-Surveillance/COVID-19-Case-Surveillance-Restricted-Access-Detai/mbd7-r32t. All other data are in the public domain and referenced in the Supplemental Text. R code is available in a public repository (https://github.com/cdcepi/COVID-19-Mitigation_Rt). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present work are contained in the manuscript

@jeffgilchrist: #Novavax vs mRNA vaccine This thread explains how @Novavax is different from the #Moderna and #Pfizer #mRNA #vaccines and describes some of the benefits such as broadened #variant recognition, more d...…

#Novavax vs #mRNA #vaccineThe table of contents and link for the unrolled one-page version of the thread can be found in the next tweet once it is posted. 👇 pic.twitter.com/iptJx3Q86q— Jeff Gilchrist (@jeffgilchrist) September 10, 2023

DMZ – MEDIZIN ¦ Markus Golla ¦ Infektions- und Immunitätsstatus der Bevölkerung gelten als Schlüsselparameter für den Umgang mit Pandemien. Dafür ist der Nachweis von Antigenen und Antikörpern von großer Bedeutung. Die derzeit dafür verwendeten Geräte – so genannte Point-of-Care (POC) Geräte – sind eine Option für ein schnelles Screening. Allerdings muss ihre Empfindlichkeit weiter verbessert werden. Dies ist Wissenschaftler*innen am Helmholtz-Zentrum Dresden-Rossendorf (HZDR) gelungen, indem sie einen auf Goldnanodrähten basierenden Nanobiosensor entwickelt haben, wie die Forscher*innen in der Fachzeitschrift ACS Publications (DOI: 10.1021/acssensors.2c01686) berichten. Inzwischen ist aus zahlreichen Studien bekannt, dass für den Nachweis von SARS-CoV-2 so genannte POC-Lateral-Flow-Tests (LFT) eine gute und genaue Alternative zur Reversen Transkriptase-Polymerase-Kettenreaktion, den allgemein bekannten PCR- Tests, darstellen. Zu den zahlreichen Vorteilen der LFT gegenüber PCR-Tests gehören die schnelle Erkennung, die Vor-Ort-Untersuchung, die niedrigen Kosten und der Betrieb ohne Laborausrüstung. Der größte Nachteil der POC-Biosensoren besteht jedoch darin, dass ihre Empfindlichkeit von der Viruslast abhängig ist. Bei einer hohen Viruslast beträgt die Empfindlichkeit 100 Prozent, bei einer niedrigen Viruslast kann die Empfindlichkeit dagegen unter 10 Prozent fallen. Dies kann zu falsch-negativen Tests führen. Ziel der HZDR-Wissenschaftler*innen war es, Sensorsysteme zu entwickeln, die auch für den Nachweis geringer Viruslasten verwendet werden können und dabei schnelle und genaue Ergebnisse liefern. Dafür hat das Team um Dr. Larysa Baraban am Institut für Radiopharmazeutische Krebsforschung Nanodrähte aus Gold verwendet, mit deren Hilfe verschiedene Biomoleküle, wie Enzyme, Proteine und Antikörper, nachgewiesen werden können. Kombiniert wurde dieses Vorgehen mit der elektrochemischen Impedanzspektroskopie, einem Verfahren, das Informationen über verschiedene Prozesse an der Grenzfläche zwischen Elektrode und Elektrolyt, einschließlich Ladungstransfer, Diffusionstransport und Bildung einer elektrischen Doppelschicht, sowie über die Eigenschaften des Messsystems, wie Lösungswiderstand und Rauheit oder Porosität der Elektrodenoberfläche liefert. „In unserer Arbeit haben wir einen nanoskopischen Biosensor-Chip entwickelt, der aus sechs Paaren von ineinandergreifenden Gold-Nanodrähten-Bauelementen zum Nachweis von SARS-CoV-2-Antigenen und -körpern besteht“, beschreibt Baraban das Projekt. „Damit ist es möglich, sowohl COVID-19-assoziierte Antigene als auch entsprechende Antiköper, die während und nach der Infektion mit dem Virus auftreten, nachzuweisen. Wir gehen davon aus, dass das Verfahren auch auf andere Biomarker und Krankheitserreger übertragbar ist. Die funktionelle Schicht, die auf das Biomolekül abzielt, muss dazu entsprechend geändert werden.“ Aktuell laufen Überlegungen und Gespräche mit der Industrie, wie der Sensor preisgünstig in großen Mengen hergestellt werden kann. Diese Maßnahme wird mitfinanziert aus Steuermitteln auf Grundlage des vom Sächsischen Landtag beschlossenen Haushalts. Originalpublikation: Impedimetric Nanobiosensor for the Detection of SARS-CoV-2 Antigens and Antibodies Diana Isabel Sandoval Bojórquez,Željko Janićijević, Brenda Palestina Romero, Eduardo Sergio Oliveros Mata, Markus Laube, Anja Feldmann, Alexandra Kegler, Laura Drewitz, Ciarán Fowley, Jens Pietzsch, Juergen Fassbender, Torsten Tonn, Michael Bachmann, and Larysa Baraban DOI: 10.1021/acssensors.2c01686

We identified five laboratory studies. Amyloid fibrin(ogen) particles were identified in participants across all studies, including those with PCC, healthy individuals, and those with diabetes. The results of three studies were based on visual images of amyloid fibrin(ogen) particles, which did not quantify the amount or size of the particles identified. Formal risk of bias assessment showed concerns in how the studies were conducted and reported. This means the results were insufficient to support the belief that amyloid fibrin(ogen) particles are associated with PCC, or to determine whether there is a difference in the amount or size of amyloid fibrin(ogen) particles in the plasma of people with PCC compared to healthy controls.

Since vaccination adherence is crucial in reducing morbidity and mortality during a pandemic, we characterized the association between demographic, in…

COVID-19, caused by the SARS-CoV-2 virus, initially identified as a respiratory illness, has increasingly been linked to a broader range of organ complications. This systematic review explores the impact of COVID-19 on cardiovascular and cerebrovascular health, focusing on thromboembolic events in post-COVID patients. A comprehensive literature search was conducted in PubMed and Google Scholar databases up to July 2023, utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies meeting eligibility criteria were analyzed for outcomes and associations between COVID-19 and cardiovascular and cerebrovascular events. The review includes 6 studies involving over 12 million patients, demonstrating a strong connection between COVID-19 and elevated risks of cardiovascular and cerebrovascular thromboembolic events. The risk of these events is evident in conditions such as ischemic heart disease, stroke, and cardiac arrhythmias. The burden of these events beyond the acute phase of the disease is concerning, warranting further exploration of long-term implications. Variability in event rates among different cohorts and healthcare settings underscores the need for understanding underlying factors influencing these differences. Potential mechanisms behind these events include endothelial dysfunction, systemic inflammation, and viral invasion. Implications for public health policies, clinical guidelines, and future research directions are discussed. This review serves as a valuable resource for healthcare providers, policymakers, and researchers to enhance patient care, outcomes, and preparedness for future waves of COVID-19 infections. However, there remain unexplored aspects of the COVID-19 and thromboembolic events relationship, urging further investigations into mechanistic insights and potential therapeutic interventions. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The data used in the study was taken from publically available researches published on google scholar and pubmed and have been cited in the references. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors

Paxlovid showed no significant reduction in the risk of all-cause mortality on day 28 and the duration of SARS–CoV-2 RNA clearance in hospitalized adult COVID-19 patients with severe comorbidities.

Three years into the pandemic, the short- and long-term risks are becoming more clear.

Study Finds Post-COVID Fatigue Lasts Up to 20 Months - Express Healthcare Management

Signal Transduction and Targeted Therapy - Azvudine is a thymus-homing anti-SARS-CoV-2 drug effective in treating COVID-19 patients

Dear Editor,

To design effective vaccines and other immune interventions against a pathogen, it is necessary to know which aspect of immunity associates with protection. We investigated whether neutralizing antibodies associate with infection clearance in long-term SARS-CoV-2 infection during HIV-mediated immunosuppression. We monitored neutralizing antibody activity against SARS-CoV-2 over 1 to 2 years in five participants with advanced HIV disease and delayed control of HIV viremia. These participants had persistent SARS-CoV-2 infection ranging from 110 to 289 days which was associated with low or undetectable neutralizing antibody responses. SARS-CoV-2 clearance was associated with the emergence of neutralizing antibodies and occurred in two participants before suppression of HIV viremia, but after some CD4 T cell reconstitution. Vaccination only further increased neutralizing antibody levels in the advanced HIV disease participants who achieved HIV suppression pre-vaccination. During the prolonged SARS-CoV-2 infection we observed widespread evolution which was particularly pronounced in one Delta variant infection. This resulted in high-level escape from Delta-elicited neutralizing antibodies and a virus antigenically distinct from both ancestral SARS-CoV-2 and Omicron XBB in hamster experimental infections. The results offer new evidence that neutralizing antibodies associate with SARS-CoV-2 clearance and argue that successful management of HIV may be necessary to curtail long-term infection and evolution of co-infecting pathogens. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was supported by the Bill and Melinda Gates award INV-018944 (AS), Wellcome Trust Award 226137/Z/22/Z (AS and PLM) and the South African Medical Research Council (AS and PLM). PLM is supported by the South African Research Chairs Initiative of the Department of Science and Innovation and National Research Foundation of South Africa. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: All blood samples used for neutralization studies, nasopharyngeal swabs from the advanced HIV disease participants for outgrowth and sequencing, as well as nasopharyngeal swabs for isolation of the ancestral/D614G, Beta, and Delta virus were obtained after written informed consent from adults with PCR-confirmed SARS-CoV-2 infection enrolled in a prospective cohort of SARS-CoV-2 infected individuals at the Africa Health Research Institute approved by the Biomedical Research Ethics Committee at the University of KwaZulu-Natal (reference BREC/00001275/2020). The Omicron/BA.1 virus was isolated from residual swab used for diagnostic testing (Witwatersrand Human Research Ethics Committee reference M210752). The nasopharyngeal swab for isolation of the Omicron XBB.1.5 subvariant was collected after written informed consent as part of the COVID-19 transmission and natural history in KwaZulu- Natal, South Africa: Epidemiological Investigation to Guide Prevention and Clinical Care in the Centre for the AIDS Programme of Research in South Africa (CAPRISA) study and approved by the Biomedical Research Ethics Committee at the University of KwaZulu-Natal (reference BREC/00001195/2020, BREC/00003106/2021). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present work are contained in the manuscript

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This study used a population-based individual patient data set that included diagnoses of COVID-19 to determine whether there was a temporal association between COVID-19 and type 1 diabetes in children.

Base case results suggest the Moderna Fall Campaign would decrease the expected 64.2 million symptomatic infections by 7.2 million (11%) to 57.0 million. COVID-19-related hospitalizations and deaths are expected to decline by 343,000 (-29%) and 50,500 (-33%), respectively. The Moderna Fall Campaign would increase QALYs by 740,880 and healthcare costs by $5.7 billion relative to No Vaccine, yielding an ICER of $7,700 per QALY gained. Using a societal cost perspective, the ICER is $2,100. Sensitivity analyses suggest that vaccine effectiveness, COVID-19 incidence, hospitalization rates and costs drive cost-effectiveness. With a relative vaccine effectiveness (rVE) of Moderna versus Pfizer-BioNTech of 5.1% for infection and 9.8% for hospitalization, use of the Moderna vaccine is expected to prevent 24,000 more hospitalizations and 3,300 more deaths than the Pfizer-BioNTech vaccine.

Es halten sich hartnäckig Mutmaßungen, dass beim Einsatz von Paxlovid zur Behandlung von Covid-19 mit einem Rebound zu rechnen sei. Ob das so st...

Screening hospitalized COVID-19 patients for cancer could potentially save lives, a new study suggests.

Die neue "Pirola"-Variante besorgt nun auch die israelischen Behörden. Sie ordneten jetzt eine neue Testpflicht an.

In diesem ePaper widmet sich das BARMER Institut für Gesundheitssystemforschung (bifg) der Untersuchung der Übersterblichkeit in den Pandemi ..

We analyzed the kinetics and durability of the humoral responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and vaccination using 8,000 longitudinal samples collected over a three-year period (April 2020 – April 2023) in the New York City metropolitan area. Upon primary immunization, participants with pre-existing immunity mounted higher antibody responses faster and achieved higher steady-state levels compared to naïve individuals. Antibody durability was characterized by two phases: an initial rapid decay, followed by a phase of stabilization with very slow decay resulting in an individual spike binding antibody steady state. Booster vaccination equalized the differences in antibody levels between participants with and without hybrid immunity, but the antibody titers reached decreased with each successive antigen exposure. Break-through infections increased antibody titers to similar levels as an additional vaccine dose in naïve individuals. Our study provides strong evidence for the fact that SARS-CoV-2 antibody responses are long lasting, with an initial waning phase followed by a stabilization phase.

This cohort study analyzes rates of hospital-onset SARS-CoV-2 infections and their association with hospital-level characteristics and testing practices.

Coronavirus disease 2019 (COVID-19) vaccines have saved millions of lives. However, variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged causing large numbers of breakthrough infections. These developments necessitated the rollout of COVID-19 vaccine booster doses. It has been reported that mucosal antibody levels in the upper respiratory tract, especially for secretory IgA (sIgA), correlate with protection from infection with SARS-CoV-2. However, it is still unclear how high levels of mucosal antibodies can be induced. In this study, we measured serum IgG, saliva IgG and saliva sIgA responses in individuals who received COVID-19 mRNA booster vaccinations or who experienced breakthrough infections. We found that mRNA booster doses could induce robust serum and saliva IgG responses, especially in individuals who had not experienced infections before, but saliva sIgA responses were weak. In contrast, breakthrough infections in individuals who had received the primary mRNA vaccination series induced robust serum and saliva IgG as well as saliva sIgA responses. Individuals who had received a booster dose and then had a breakthrough infection showed low IgG induction in serum and saliva but still responded with robust saliva sIgA induction. These data suggest that upper respiratory tract exposure to antigen is an efficient way of inducing mucosal sIgA while exposure via intramuscular injection is not. Importance Antibodies on mucosal surfaces of the upper respiratory tract have been shown to be important for protection from infection with SARS-CoV-2. Here we investigate the induction of serum IgG, saliva IgG and saliva sIgA after COVID-19 mRNA booster vaccination or breakthrough infections.