Inledning: God vårdhygien är ett centralt begrepp inom all hälso- och sjukvård för att förhindra spridning av sjukdomsframkallande mikroorganismer, vilka kan ge upphov till vårdrelaterade infektioner. Tandvården ska därför följa Hälso- och sjukvårdslagen (1982:763) och Socialstyrelsens föreskrifter om basala hygienrutiner. I samband med Covid-19 pandemin aktualiserades vikten av vårdhygien ytterligare för att förhindra smittspridning av Covid-19 inom tandvården. Munhålan utgör en stor potentiell risk för överföring av SARS-CoV-2, men även andra mikroorganismer, särskilt vid aerosolgenererande procedurer.  Ett tidigare mastersarbete vid Odontologiska fakulteten, Malmö Universitet, påvisade brister i följsamheten med basala hygienrutiner bland tandläkarstudenter. En uppföljning har inte genomförts, vilket uppmärksammades i samband med pandemin och frågeställningen om Covid-19 syn på betydelsen av aseptik och vårdhygien väcktes.  Syfte: Undersöka tandläkarstudenters syn på vårdhygien och självbedömd följsamhet med hygienriktlinjer under Covid-19.  Material och metod: En anonym webbenkät skickades till samtliga tandläkarstudenter på kurs 4–10 vid Odontologiska fakulteten, Malmö Universitet.  Resultat: Den totala svarsfrekvensen var 54%. Resultat visade att samtliga studenter ansåg sig ha tillräckliga kunskaper om hygienrutinerna, men trots detta bröt 20% medvetet mot hygienrutinerna och 4% uppgav att de aldrig följde hygienrutinerna.  Slutsats: Den självbedömda kunskapen om hygienriktlinjer är hög, trots det är inte följsamheten med hygienriktlinjerna optimal, vilket innebär att det finns risk för spridning av vårdrelaterade infektioner. / Introduction: Good hygiene is imperative to prevent the spread of health care associated infections. Dental care must therefore comply with the Health and Medical Services Act (1982: 763) and the National Board of Health and Welfare's regulations on basic hygiene guidelines. In conjunction with the Covid-19 pandemic, the importance of hygiene measures was further emphasized to prevent the spread of Covid-19 in dentistry. The oral cavity poses a high potential risk for transmission of SARS-CoV-2, in addition to other microorganisms, especially in aerosol-generating procedures.  A previous master's thesis at the Faculty of Odontology, Malmö University, showed a deficiency in compliance with hygiene guidelines among dental students. The question if Covid-19 view of the importance of aseptic techniques and hygiene measures in dentistry was therefore raised.  Aim: Investigate dental students' views of healthcare hygiene and self-assessed aseptic measures during Covid-19.  Materials and method: An anonymous web survey was sent to all dental students in courses 4–10 at the Faculty of Odontology, Malmö University.  Results: The overall response rate was 54%. Results showed that all students considered themselves to have sufficient knowledge of the hygiene routines, but despite this, 20% of students deliberately broke the hygiene routines and 4% stated that they never followed the hygiene routines.  Conclusion: The self-assessed awareness of hygiene guidelines and aseptic techniques is high among the students, still the compliance with hygiene protocols is not optimal, meaning there is a risk of spread of healthcare associated infections.

Objetivo: Identificar los factores influyentes en la postura ante la inmunización SARSCoV-2 en estudiantes de medicina de una universidad de Lambayeque en el año 2021. Materiales y métodos: Se realizó un estudio tipo observacional transversal analítico. Se tomó a toda la población elegible,que constó de aproximadamente 160 estudiantes y se distribuyó con un muestreo probabilístico tipo estratificado. El cuestionario elaborado se basó en la encuesta online de la Organización de Consumidores y Usuarios (OCU) titulada “Encuesta OCU: los españoles y la vacuna” que fue realizada en España. Para el análisis estadístico se empleó la herramienta estadística IBM SPSS Statistics 25.0.0.0. Se tabularon las variables categóricas para la distribución de frecuencia y porcentajes, y se realizó un análisis bivariado entre las variables de interés y las variables de desenlace, mediante la prueba exacta de Fisher. Resultados: Se encuestó a 155 de 160 universitarios, el 94,8% fueron jóvenes (18-25 años). El semestre académico que representó mayor porcentaje fue octavo ciclo. La mayoría de los ítems del cuestionario obtuvieron el puntaje de 3 puntos según la escala de Likert. El 96,8% de universitarios manifestaron que sí se vacunarían tan pronto como pudieran. Se obtuvo que el factor influyente en la postura ante la inmunización SARS-CoV-2 fue el de la efectividad de la vacuna reduciendo la mortalidad por COVID – 19. Conclusiones: Se concluye que la mayoría de los estudiantes se encontraron a favor de la vacunación. Además, la efectividad de la vacuna reduciendo la mortalidad por COVID-19, fue el único factor influyente. / Objective: To identify the influential factors in the posture before SARS-CoV-2 immunization in medical students of a Lambayeque university in the year 2021. Materials and methods: An analytical cross-sectional observational study was carried out. The entire eligible population was taken, which consisted of approximately 160 college students and was distributed with a stratified probabilistic sampling. The questionnaire prepared was based on the online survey of the Organization of Consumers and Users (OCU) entitled "OCU Survey: Spaniards and the vaccine" that was carried out in Spain. For the statistical analysis, the statistical tool IBM SPSS Statistics 25.0.0.0 was used. Categorical variables were tabulated for frequency distribution and percentages, and a bivariate analysis was performed between the variables of interest and the outcome variables, using Fisher's exact test. Results: 155 of 160 university students were surveyed, 94.8% were young (18-25 years). The semester of studies that represented the highest percentage was eighth cycle. Most of the ítems in the questionnaire obtained a score of 3 points according to the Likert scale. 96.8% of university students stated that they would get vaccinated as soon as they could. It was found that the influential factor in the posture before SARS-CoV-2 immunization was the effectiveness of the vaccine in reducing mortality from COVID-19. Conclusions: It is concluded that the majority of students were in favor of vaccination. Also, the effectiveness of the vaccine in reducing mortality from COVID-19 was the only influential factor.

Bakgrund, de restriktioner och rekommendationer som människor fått förhålla sig till under COVID-19 pandemin har inneburit en annorlunda och förändrad vardag. En grupp som blivit drabbad är högskole- och universitetsstudenter som bland annat fått byta de fysiska klassrummen mot diverse online plattformar. Tidigare forskning har utförts, men hur aktivitetsmönstret har förändrats är dock mindre utforskat. Syftet med studien var att kartlägga förändring i aktivitetsmönstret hos högskole- och universitetsstudenter under COVID-19 pandemin. Metoden som användes hade en kvantitativ design i form av tvärsnittsstudie. Ett bekvämlighetsurval användes och respondenter rekryterades via sociala medier (Facebook). Populationen bestod av 49 studenter. Deskriptiv statistik användes för att beskriva insamlade data. Resultatet visade på en förändring i studenternas aktivitetsmönster och en koppling mellan förlust av meningsfulla aktiviteter, nöjdhet gällande sin aktivitetsfördelning samt upplevd vardagsbalans kunde urskiljas. Slutsats, övergripande hade förändringarna i studenternas aktivitetsmönster påverkats till det negativa. Författarna till föreliggande studie har en förhoppning om att studien ska leda till ökad förståelse gällande människors aktivitetsmönster som relaterar till den hälsoproblematik som kan uppstå under situationer som den rådande COVID-19 pandemin. / Background, this thesis describes the restrictions and recommendations that people have had to follow during the COVID-19 pandemic, and how these have led to a different and altered everyday life. College- and University students are one group that have been affected, especially since they had to switch from in-person learning to online platforms. There have been prior studies regarding the health of students and how their health has been affected during the pandemic, however the extent to which the occupational pattern of students has changed has been less explored. The purpose of this study was to investigate the change in student’s occupational patterns during the COVID-19 pandemic. The method that was used was a quantitative design. A convenience sample was used, and the respondents were recruited through social media platforms (Facebook). The population included 49 students. Descriptive statistics were used to describe the data that was collected from the survey. Results, the study showed a change in student’s occupational patterns during the COVID-19 pandemic and a connection was seen between loss of meaningful activities, satisfaction regarding their activity distribution, and perceived everyday balance. In conclusion, the overall changes in student’s occupational patterns had a negative effect. The authors expect that this study will lead to a higher understanding of the occupational patterns that relate to the health problems that can occur during situations such as the COVID-19 pandemic.

Bakgrund: Covid-19 pandemin som orsakades av Sars-Cov-2-viruset innebar en betydande utmaning för världen. I synnerhet påverkades hälso- och sjukvården av dess framfart. Sjuksköterskor som arbetade inom slutenvården under denna tid var särskilt utsatta och föremål för en rad olika upplevelser både positiva och negativa. Dessa erfarenheter är värdefulla att analysera för att bättre kunna hantera kommande pandemier. Syfte: Att undersöka sjuksköterskors upplevelser inom slutenvården under covid-19 pandemin. Metod: Litteraturöversikt genomförd i enlighet med Fribergs metod. Elva kvalitativa originalartiklar valdes från databaserna PubMed och Cinahl Complete för analys. Resultat: Tre huvudteman identifierades vilka var: Rädsla, Osäkerhet och Sjuksköterskans upplevelser rörande yrkesrollen. Slutsats: Rädsla var en dominerande upplevelse bland sjuksköterskor och antog ett flertal olika former. Sjuksköterskor upplevde även osäkerhet relaterat till det oklara kunskapsläget, föränderlig information, den egna kompetensen samt brist på material och personal. Sjuksköterskor upplevde både positiva och negativa känslor relaterade till yrkesrollen. Förberedelse i form av utbildning av sjuksköterskor och allmänhet, genomtänkta rutiner och riktlinjer samt förbättrad lagerhållning av skyddsmaterial är viktigt för att minska negativa effekter under kommande pandemier. / Background: The Covid-19-pandemic caused by the Sars-Cov-2-virus constituted a significant challenge for the world. In particular the healthcare systems were affected during its course. Nurses working within inpatient care were especially vulnerable and might have had several different experiences, which could be either negative or positive. These experiences are valuable and worth analyzing in order to be better prepared for forthcoming pandemics. Aim: To analyze nurses´experiences in inpatient care during the Covid-19 pandemic. Method: A literary overview conducted in accordance with the method of Friberg. Eleven qualitative original articles were selected from the databases PubMed and Cinahl Complete and analyzed. Results: Three main themes were identified which were: Fear, uncertainty and nurses experiences related to the profession. Conclusions: Fear was a dominant experience among nurses and took a variety of forms. Nurses also experience uncertainty related to the unclear state of knowledge, changing information, their own competence and due to a shortage of materials and other staff. Nurses experienced both positive and negative emotions in relation to their profession. Preparation in the form of eduaction for both nurses and the general public, well-thought-out routines and guidelines as well as improved stockpiling of protective equipment is essential to reduce the negative effects of future pandemics.

Purpose: To quantify the number of SARS-CoV-2 infections in students and teachers in 14 Secondary schools in eastern Saxony, Germany. Seroprevalence of SARS-CoV-2 antibodies in study population. Number of undetected cases. - Methods: Serial seroprevalence study. - Results: The role of educational settings in the SARS-CoV-2 Pandemic is still controversial. Seroprevalence increases from 0.8 to 5.9% from October to December when schools remained open and to 12.2% in March/April during a strict lockdown with closed schools. The ratio of undetected to detected cases decreased from 0.76 to 0.44 during the study period. - Conclusion: During the second and third wave of the pandemic in Germany, students and teachers are not overrepresented in SARS-CoV-2 infections. The percentage of undetected cases is moderate and decreases over time. The risk of contracting SARS-CoV-2 within the household is higher than contracting it in educational settings making school closures rather ineffective in terms of pandemic control measures or individual risk reduction in children and adolescents. - Trial registration: DRKS00022455 (July 23rd, 2020).

The outbreak of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019 in Wuhan challenges pediatric oncologists in an unexpected way. We provide a comprehensive overview, which systematically summarizes and grades evidence (QoE) on SARS-CoV-2 infections in pediatric cancer patients at 1.5 years of pandemic. A systematic literature search in PubMed combined with an additional exploratory literature review in other international databases was conducted to identify studies on children (aged < 18 years) with a malignant disease and COVID-19 infections. In total, 45 reports on 1003 pediatric cancer patients with SARS-CoV-2 infections were identified out of 1397 reports analyzed. The clinical course of COVID-19 was reported mild or moderate in 358 patients (41.7%), whereas 11.1% of patients showed severe COVID-19. In 12.7% of patients, chemotherapy was postponed, whereas 19% of patients with different underlying malignancies received chemotherapy during SARS-CoV-2 infection. Twenty-five patients with SARS-CoV-2 infections died, potentially related to COVID-19. Conclusion: Despite a favorable COVID-19 outcome in most pediatric cancer patients, the morbidity is reported higher than in children without comorbidities. However, no severe COVID-19 complications were associated to the continuation of chemotherapy in some cohort studies and reports on two patients. Therefore, the risk of cancer progress or relapse due to interruption of chemotherapy has carefully to be weighed against the risk of severe COVID-19 disease with potentially fatal outcome.

Wastewater surveillance for SARS-CoV-2 has been demonstrated to be a valuable tool in monitoring community-level virus circulation and assessing new outbreaks. It may become a useful tool in the early detection and response to future pandemics, enabling public health authorities to implement timely interventions and mitigate the spread of infectious diseases with the fecal excretion of their agents. It also offers a chance for cost-effective surveillance. Reverse transcription-quantitative polymerase chain reaction (RTqPCR) is the most commonly used method for viral RNA detection in wastewater due to its sensitivity, reliability, and widespread availability. However, recent studies have indicated that reverse transcription droplet digital PCR (RTddPCR) has the potential to offer improved sensitivity and accuracy for quantifying SARS-CoV-2 RNA in wastewater samples. In this study, we compared the performance of RTqPCR and RTddPCR approaches for SARS-CoV-2 detection and quantification on wastewater samples collected during the third epidemic wave in Saxony, Germany, characterized by low-incidence infection periods. The determined limits of detection (LOD) and quantification (LOQ) were within the same order of magnitude, and no significant differences were observed between the PCR approaches with respect to the number of positive or quantifiable samples. Our results indicate that both RTqPCR and RTddPCR are highly sensitive methods for detecting SARS-CoV-2. Consequently, the actual gain in sensitivity associated with ddPCR lags behind theoretical expectations. Hence, the choice between the two PCR methods in further environmental surveillance programs is rather a matter of available resources and throughput requirements.

Inhalt der Dissertation sind die Ergebnisse der SchoolCoviDD19-Studie, welche von Mai 2020 bis Juli 2021 an ostsächsischen Schule durchgeführt wurde. Es wurde die Entwicklung der Seroprävalenz von SARS-CoV-2 bei Schüler:innen und Lehrer:innen, sowie der Verlauf der Dunkelziffer untersucht. Sekundär sollten Erkenntnisse über die Bedeutung von Bildungseinrichtungen auf das Transmissionsgeschehen in der Allgemeinbevölkerung gewonnen werden.

Hintergrund: Eine plötzlich auftretende Riechstörung ist ein spezifisches Symptom eines viral bedingten oberen Atemwegsinfekts und v. a. auch für das SARS-CoV-2-Virus (Haehner et al., 2020). Obwohl die meisten infizierten Personen (75 %) nur eine vorübergehende Symptomatik erleben (Niklassen et al., 2021), sind ca. 5 % von persistierenden Beschwerden bis zu über einem Jahr betroffen (Tan et al., 2022). Fragestellung: Die vorliegende Studie beschäftigte sich mit der Frage, ob ein Riechtraining (RT) mit Begleitmedikation durch Vitamin-A-Nasentropfen oder Mometasonfuroat-Nasenspray bei persistierender Riechstörung postinfektiöser Genese einen Zusatznutzen in der Wiederherstellung der Riechfunktion und eine Verbesserung von Parosmien bringt. Material und Methoden: In dieser prospektiven Interventionsstudie führten alle 146 Patienten im Alter zwischen 20 und 83 Jahren mit persistierender Riechstörung ein zwölfwöchiges Riechtraining (RT) durch. Zweiundfünfzig Patienten bildeten die Riechtrainingskontrollgruppe, 52 weitere nahmen zusätzlich Vitamin-A-Nasentropfen in der „Kaiteki“-Position ein und 42 bekamen ergänzend zum RT Mometasonfuroat-Nasenspray mit einem langen Applikator verschrieben. Die orthonasale Riechfunktion wurde mittels Sniffin‘ Sticks und die retronasale Funktion mit Schmeckpulvern bestimmt. Zusätzlich bewerteten die Patienten ihre subjektive Riechleistung und Nasenatmung. Anschließend beantworteten sie Fragebögen zur jeweiligen therapeutischen Intervention. Ergebnisse: Die Analyse zeigte statistisch signifikante Verbesserungen aller Interventionsgruppen in fast allen untersuchten olfaktorischen Funktionskategorien. Die Gruppen unterschieden sich jedoch nur bei der Geruchsschwelle, wobei die Patienten der Vitamin-A-Gruppe höhere Werte erzielten, als die beiden anderen Gruppen. Die Verwendung von Vitamin A führte zur stärkeren Verbesserung der Riechschwelle bei Parosmie-Betroffenen als bei Patienten ohne Parosmie. Schlussfolgerungen: Innerhalb eines zwölfwöchigen Interventionszeitraums scheint Vitamin A einen Zusatznutzen gegenüber Mometasonfuroat-Nasenspray oder alleinigem RT aufzuweisen.:Gendererklärung Abkürzungsverzeichnis 1. Einleitung 2. Wissenschaftliche Grundlagen 2.1 Anatomie und Physiologie des Riechens 2.2 Neurogenese und Neuroplastizität 2.3 Riechstörungen 2.3.1 Quantitativ 2.3.2 Qualitativ 2.3.3 Ursachenbezogene Einteilung von Riechstörungen 2.3.4 Diagnostik von Riechstörungen 2.4 Therapieoptionen bei Riechstörungen 2.4.1 Riechtraining (RT) 2.4.2 Vitamin A 2.4.3 Kortikosteroide 3. Zielsetzung der Studie 4. Material und Methoden 4.1 Ethik 4.2 Studiendesign und Ablauf 4.3 Rekrutierung 4.4 Auswahlkriterien 4.5 Psychophysische Olfaktometrie 4.5.1 Sniffin‘ Sticks 4.5.2 Retronasale olfaktorische Funktion 4.6 Gustometrie 4.7 Therapieoptionen 4.7.1 Riechtraining (RT) 4.7.2 Vitamin-A-Nasentropfen 4.7.3 Mometasonfuroat-Nasenspray 4.8 Fragebögen 4.9 Datenverarbeitung und Statistik 5. Ergebnisse 5.1 Studienpopulation 5.2 Quantitative Riechfunktion 5.2.1 Riechvermögen (orthonasal) 5.2.2 Riechvermögen (retronasal) 5.3 Qualitative Riechfunktion 5.4 Schmeckvermögen 5.5 Nasendurchgängigkeit 5.6 Fragebögen 5.6.1 Riechtraining 5.6.2 Vitamin A-Nasentropfen 5.6.3 Mometasonfuroat-Nasenspray 5.6.4 Parosmie 5.7 Zusammenfassung der Ergebnisse 6. Diskussion 6.1 Relevanz des Themas 6.2 Untersuchung des Patientenkollektivs 6.3 Wissenschaftliche Einordnung der Forschungsergebnisse 6.3.1 Korrelationsanalysen 6.3.2 Vergleich der Vitamin A + RT-Gruppe mit dem alleinigem RT 6.3.3 Vergleich der Mometason + RT-Gruppe mit dem alleinigem RT 6.3.4 Untersuchung der Parosmie im Interventionszeitraum 6.4 Limitationen der Studie 6.5 Schlussfolgerungen und Ausblick 7. Zusammenfassung 8. Summary Publikationsverzeichnis Literaturverzeichnis Abbildungsverzeichnis Tabellenverzeichnis Anhang / Background:Sudden onset olfactory dysfunction is one of the specific symptoms of a viral infection of the upper respiratory tract, and especially for SARS-CoV-2 (Haehner et al., 2020). Although most infected persons (75 %) only experienced transient symptoms (Niklassen et al., 2021), around 5% are affected by persistent symptoms for up to more than one year (Tan et al., 2022). Objective: The focus of this study was to investigate whether olfactory training (OT) with concomitant medication using vitamin A nose drops or mometasone furoate nasal spray provides an additional benefit in the restoration of olfactory function and improvement of parosmia in patients with persistent olfactory dysfunction due to postinfectious aetiology. Materials and methods: In this prospective intervention study, 146 patients, age 20-83 years, with persistent olfactory dysfunction, all of whom performed OT for 12 weeks. Fifty-two patients formed the OT control group, 52 additionally used vitamin A nasal drops in the “Kaiteki”-position and 42 were prescribed mometasone furoate nasal spray with a long applicator alongside with OT. Orthonasal olfactory function was determined by using Sniffin‘ Sticks, retronasal function with “taste powders”. In addition, participants rated olfactory performance and nasal patency and filled in questionnaires pertaining the respective interventions. Results: The analysis showed statistically significant improvements of all intervention groups in almost all investigated olfactory functions. However, the groups only showed differences for odor thresholds with patients in the vitamin A group exhibiting higher scores compared to the two other groups. The use of vitamin A also led to a greater improvement of olfactory threshold in patients with parosmia compared to patients without. Conclusion: Over a 12-week intervention period vitamin A appeared to exhibit a benefit over mometasone furoate nasal spray or OT only.:Gendererklärung Abkürzungsverzeichnis 1. Einleitung 2. Wissenschaftliche Grundlagen 2.1 Anatomie und Physiologie des Riechens 2.2 Neurogenese und Neuroplastizität 2.3 Riechstörungen 2.3.1 Quantitativ 2.3.2 Qualitativ 2.3.3 Ursachenbezogene Einteilung von Riechstörungen 2.3.4 Diagnostik von Riechstörungen 2.4 Therapieoptionen bei Riechstörungen 2.4.1 Riechtraining (RT) 2.4.2 Vitamin A 2.4.3 Kortikosteroide 3. Zielsetzung der Studie 4. Material und Methoden 4.1 Ethik 4.2 Studiendesign und Ablauf 4.3 Rekrutierung 4.4 Auswahlkriterien 4.5 Psychophysische Olfaktometrie 4.5.1 Sniffin‘ Sticks 4.5.2 Retronasale olfaktorische Funktion 4.6 Gustometrie 4.7 Therapieoptionen 4.7.1 Riechtraining (RT) 4.7.2 Vitamin-A-Nasentropfen 4.7.3 Mometasonfuroat-Nasenspray 4.8 Fragebögen 4.9 Datenverarbeitung und Statistik 5. Ergebnisse 5.1 Studienpopulation 5.2 Quantitative Riechfunktion 5.2.1 Riechvermögen (orthonasal) 5.2.2 Riechvermögen (retronasal) 5.3 Qualitative Riechfunktion 5.4 Schmeckvermögen 5.5 Nasendurchgängigkeit 5.6 Fragebögen 5.6.1 Riechtraining 5.6.2 Vitamin A-Nasentropfen 5.6.3 Mometasonfuroat-Nasenspray 5.6.4 Parosmie 5.7 Zusammenfassung der Ergebnisse 6. Diskussion 6.1 Relevanz des Themas 6.2 Untersuchung des Patientenkollektivs 6.3 Wissenschaftliche Einordnung der Forschungsergebnisse 6.3.1 Korrelationsanalysen 6.3.2 Vergleich der Vitamin A + RT-Gruppe mit dem alleinigem RT 6.3.3 Vergleich der Mometason + RT-Gruppe mit dem alleinigem RT 6.3.4 Untersuchung der Parosmie im Interventionszeitraum 6.4 Limitationen der Studie 6.5 Schlussfolgerungen und Ausblick 7. Zusammenfassung 8. Summary Publikationsverzeichnis Literaturverzeichnis Abbildungsverzeichnis Tabellenverzeichnis Anhang

La pandemia de COVID-19 ha sido uno de los mayores desafíos de salud pública, afectando a millones y exponiendo al personal sanitario a un alto riesgo. La vacunación es esencial para prevenir la propagación del virus y proteger a los más vulnerables. Evaluar la efectividad vacunal en el mundo real es crucial para entender su impacto, ajustar estrategias y garantizar la protección adecuada. Por todo ello, se hace necesario evaluar de una manera sistemática y rigurosa su efectividad. Los tres objetivos de esta tesis doctoral son: 1) Evaluar la efectividad de las vacunas BNT162b2 y mRNA-1273 frente al SARS-CoV-2 en los profesionales sanitarios de la Comunidad Valenciana, tras haber completado la pauta vacunal completa de dos dosis, tanto en la prevención de la infección como en la hospitalización, según el tiempo transcurrido desde su administración.; 2) Evaluar la efectividad de la vacuna BNT162b2 para la prevención de la infección por SARS-CoV-2 en profesionales sanitarios, tras finalizar una pauta completa de dos dosis, según el tiempo transcurrido desde su administración. 3) Evaluar la efectividad de las vacunas BNT162b2 y mRNA-1273 en los profesionales sanitarios de la Comunidad Valenciana, tras haber completado la pauta vacunal completa de dos dosis, tanto en la prevención de la infección como en la hospitalización, según el tiempo transcurrido desde su administración, la variante predominante y la administración de una dosis de refuerzo. Las principales conclusiones han sido: La vacunación completa con BNT162b2 y mRNA-1273 contra el SARS-CoV-2 fue altamente efectiva para prevenir casos de COVID-19 en profesionales sanitarios entre 12 y 120 días después de la segunda dosis. A medida que pasó más tiempo desde la vacunación, la efectividad disminuyó, aunque se mantuvo para prevenir la hospitalización de los profesionales sanitarios (Artículo 1). La vacunación contra la infección por SARS-CoV-2 en los profesionales sanitarios es altamente efectiva entre 12 y 120 días después de recibir dos dosis de BNT162b2. Sin embargo, esta efectividad disminuye con el tiempo transcurrido desde la vacunación (Artículo 2). La vacunación con dos dosis de Moderna-mRNA-1273 en trabajadores sanitarios fue altamente efectiva contra infecciones y hospitalizaciones durante los primeros 120 días después de la segunda dosis durante el predominio de la variante Ómicron. La EVa disminuyó después de 120 días, pero se restableció con una dosis de refuerzo, especialmente con la vacuna Pfizer, mientras que la prevención de hospitalizaciones se mantuvo estable. La vacunación con dos dosis de Moderna-mRNA-1273 en profesionales sanitarios fue altamente efectiva contra infecciones y hospitalizaciones durante los primeros 120 días después de la segunda dosis durante el predominio de la variante Ómicron. La efectividad vacunal disminuyó después de 120 días, pero se restableció con una dosis de refuerzo, especialmente con la vacuna Pfizer, mientras que la prevención de hospitalizaciones se mantuvo estable. (Artículo 3).