The influenza landscape and vaccination coverage in older adults during the SARS-Cov-2 pandemic: data from Several European Countries and Israel.

INTRODUCTION: The Raise Awareness of Influenza Strategies in Europe (RAISE) group gathered information about the healthcare burden of influenza (hospitalizations, intensive care unit [ICU] admissions, and excess deaths), surveillance systems, and the vaccine coverage rate (VCR) in older adults in 18 European countries and Israel. AREAS COVERED: Published medical literature and official medical documentation on the influenza disease burden in the participating countries were reviewed from 2010/11 until the 2022/23 influenza seasons. Information on the framework for monitoring the disease burden and the provision for ensuring older adults had access to vaccination in their respective countries was provided. Data on influenza VCR in older adults were collected for the 2019/20 to 2022/23 influenza seasons. Data are reported descriptively. EXPERT OPINION: Influenza presents a significant healthcare burden in older adults. Reporting outcomes across participating countries is heterogeneous, highlighting the need for standardized approaches. Although older adults receive free influenza vaccination, vaccine uptake is highly variable among countries. Moreover, hospitalization rates remain high even in countries reporting a high VCR. Increased awareness and education on the burden of disease and the broader use of improved influenza vaccines for older adults may help reduce the disease burden on this population.

Asclepieia in ancient Greece: pilgrimage and healing destinations, the forerunner of medical tourism.

Asclepios, the first physician-demigod in Greek mythology, was born in Thessaly of the God Apollo and Coronis, a mortal mother. Asclepieia were healing sanctuaries dedicated to Asclepios. Asclepieia were located throughout the Eastern Mediterranean area, in ancient Greece and the Roman world. Travelers from all over the Mediterranean area seeking healing made pilgrimages to the Asclepieia, the early forerunner of "medical tourism".

Effectiveness of COVID-19 vaccination against school absenteeism in children and adolescents hospitalized with COVID-19.

BACKGROUND: COVID-19 vaccination has been recommended for children to protect them and to enable in-person educational and social activities. METHODS: We estimated COVID-19 vaccination effectiveness (VE) against school absenteeism in children 5-17 years old hospitalized from September 1, 2021 through May 31, 2023. Full vaccination was defined as two vaccine doses. RESULTS: We studied 231 children admitted to hospital with COVID-19, including 206 (89.2 %) unvaccinated/partially vaccinated and 25 (10.8 %) fully vaccinated. Unvaccinated/partially vaccinated children were absent from school for longer periods compared to fully vaccinated children (median absence: 14 versus 10 days; p-value = 0.05). Multivariable regression showed that full COVID-19 vaccination was associated with fewer days of absence compared to no/partial vaccination on average (adjusted relative risk: 0.77; 95 % CI: 0.61 to 0.98). COVID-19 VE was 50.7 % (95 % CI: -11.3 % to 78.2 %) for school absenteeism above the median duration of absenteeism. CONCLUSIONS: Full COVID-19 vaccination conferred protection against school absenteeism in hospitalized school-aged children with COVID-19.

Challenges with medical tourism.

PURPOSE OF REVIEW: With the return of international travels to almost prepandemic levels, the number of patients who travel abroad to seek healthcare services is once again growing rapidly. Nevertheless, the expected benefits of medical tourism may be challenged by serious infectious complications. This review summarizes the evolving published evidence on infectious complications related with medical tourism of the last eighteen months. RECENT FINDINGS: There has been an increase of reported infectious complications in patients who had received healthcare abroad. Such complications were frequently associated with serious and prolonged morbidity, repeated treatments and hospitalizations, high healthcare costs, and occasionally fatalities. A devastating outbreak of fungal meningitis occurred among US residents who underwent epidural anesthesia for cosmetic surgery in two clinics in Mexico. Overall, as of July 5, 2023 there were 31 cases with severe cerebrovascular complications and eight deaths. Infections caused by nontuberculum mycobacteria and Candida sp have been also reported the last years. SUMMARY: Considering the expected expansion of medical tourism in the forthcoming years, public health authorities and scientific societies should raise awareness of such infections among physicians and other healthcare professionals and issue recommendations for their management. A system to report complications in patients receiving healthcare abroad is needed.

National vaccination policies for health workers - A cross-sectional global overview.

BACKGROUND: Immunization is essential for safeguarding health workers from vaccine-preventable diseases (VPDs) that they may encounter at work; however, information about the prevalence and scope of national policies that protect health workers through vaccination is limited. Understanding the global landscape of health worker immunization programmes can help direct resources, assist decision-making and foster partnerships as nations consider strategies for increasing vaccination uptake among health workers. METHODS: A one-time supplementary survey was distributed to World Health Organization (WHO) Member States using the WHO/United Nations Children's Fund (UNICEF) Joint Reporting Form on Immunization (JRF). Respondents described their 2020 national vaccination policies for health workers - detailing VPD policies and characterising technical and funding support, monitoring and evaluation activities and provisions for vaccinating health workers in emergencies. RESULTS: A total of 53 % (103/194) Member States responded and described health worker policies: 51 had a national policy for vaccinating health workers; 10 reported plans to introduce a national policy within 5 years; 20 had subnational/institutional policies; 22 had no policy for vaccinating health workers. Most national policies were integrated with occupational health and safety policies (67 %) and included public and private providers (82 %). Hepatitis B, seasonal influenza and measles were most frequently included in policies. Countries both with and without national vaccination policies reported monitoring and reporting vaccine uptake (43 countries), promoting vaccination (53 countries) and assessing vaccine demand, uptake or reasons for undervaccination (25 countries) among health workers. Mechanisms for introducing a vaccine for health workers in an emergency existed in 62 countries. CONCLUSION: National policies for vaccinating health workers were complex and context specific with regional and income-level variations. Opportunities exist for developing and strengthening national health worker immunization programmes. Existing health worker immunization programmes might provide a foothold on which broader health worker vaccination policies can be built and strengthened.

Influenza immunization of healthcare personnel in the post-COVID-19 pandemic era: Still a lot to do!

Healthcare-associated influenza is frequently encountered in healthcare settings with significant morbidity and mortality among vulnerable patients, absenteeism among healthcare personnel (HCP), and interruption of healthcare services. Numerous investigations indicate that nosocomial outbreaks are often traced to HCP. Despite the international and national endorsements, seasonal influenza vaccine acceptance among HCP continues suboptimal worldwide. Infection control is the major objective for healthcare risk management in order to guarantee patient safety, limit the cost of hospitalization and assurance health management in controlling influenza seasons. Vigilance and anticipation are required as globally we are moving from a reactive COVID-19 pandemic response phase to one of planning for the co-circulation of viral respiratory infections. Declining to understand HCP perception of influenza risk and acceptance of vaccination might have impact patient safety as well as healthcare services.

Hepatitis B in Healthcare Personnel: An Update on the Global Landscape.

Despite the outstanding progress that has been made in the prevention, detection, and management of hepatitis B during the past decades, hepatitis B remains a problem among healthcare personnel (HCP) in many countries. We reviewed studies on all aspects of hepatitis B in HCP published from 2017 through April 2023. They revealed wide variations on the prevalence of infection among HCP, ranging from 0.6% in Europe to >8.7% in Africa, almost always in association with very low vaccination rates. Many studies found a significant association between HCP's knowledge about hepatitis B and hepatitis B vaccines, their vaccination status, and practices. This research also discloses global inequities regarding vaccination policies against hepatitis B, free-of-charge vaccinations, and access to post-exposure prophylaxis (PEP). Strategies to prevent and manage accidental exposures are needed in order to reduce the burden of hepatitis B on HCP, while written policies for all aspects of infection prevention, protective equipment, and PEP should be available. Lastly, HCP should be accordingly educated. These are all imperative given the decline of routine vaccinations in the COVID-19 era, particularly in countries with fragile vaccination programs, and the disruptions of interventions for hepatitis B that are expected to provide a pool of virus transmission to future generations.

Absenteeism of Healthcare Personnel in the COVID-19 Era: A Systematic Review of the Literature and Implications for the Post-Pandemic Seasons.

This systematic review aimed to assess COVID-19-associated absenteeism among healthcare personnel (HCP). PubMed was searched on 4 February 2023. Inclusion criteria were the presentation of original data on COVID-19-associated absenteeism among HCP. Exclusion criteria were absenteeism associated with burnout, mental health illness, post-COVID syndrome, or child-care. Nineteen articles were identified; fifteen concerned almost exclusively the first pandemic year. Hospitals accounted for most data. There was heterogeneity across studies in terms of presentation of absenteeism data. Before COVID-19 vaccines became available, COVID-19 was a major driver of HCP absenteeism with excess costs, while the mean duration of absenteeism ranged from 5.82 to 33 days per episode of absence. Determinant factors of absenteeism rates were department of employment, high-risk exposure, age, profession, and work experience of HCP, suspected COVID-19, SARS-CoV-2 testing, SARS-CoV-2 positivity, and return-to-work strategy. Two studies demonstrated that COVID-19 vaccination significantly reduced the burden of absenteeism. Routine testing of asymptomatic HCP and use of personal protective equipment also significantly ameliorated absenteeism. In conclusion, COVID-19 has been a major driver of HCP absenteeism. Research is needed to assess how COVID-19 will impact HCP in the next years, considering the new SARS-CoV-2 variants, the co-circulation of other respiratory viruses, and the newer COVID-19 vaccines. Networks are needed to survey morbidity and absenteeism among HCP in real-time and guide vaccination policies.

Carbapenem-Resistant Pseudomonas aeruginosa Bacteremia, through a Six-Year Infection Control Program in a Hospital.

BACKGROUND: Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a life-threatening healthcare-associated infection affecting especially patients with immunosuppression and comorbidities. We investigated the association between the incidence of CRPA bacteremia, antibiotic consumption, and infection control measures in a hospital during 2013-2018. METHODS: We prospectively recorded the incidence of CRPA bacteremia, antibiotic consumption, use of hand-hygiene solutions, and isolation rates of multidrug-resistant (MDR) carrier patients. FINDINGS: The consumption of colistin, aminoglycosides, and third-generation cephalosporins decreased significantly in the total hospital and its divisions (p-value < 0.001 for all comparisons) while the consumption of carbapenems decreased significantly in the adults ICU (p-value = 0.025). In addition, the incidence of CRPA significantly decreased in the total hospital clinics and departments (p-values = 0.027 and 0.042, respectively) and in adults clinics and departments (p-values = 0.031 and 0.051, respectively), while in the adults ICU, the incidence remained unchanged. Increased isolation rates of MDR carrier patients, even two months before, significantly correlated with decreased incidence of CRPA bacteremia (IRR: 0.20, 95% CI: 0.05-0.73, p-value = 0.015) in the adults ICU. Interestingly, when the use of hand-hygiene solutions (alcohol and/or scrub) increased, the consumption of advanced, nonadvanced, and all antibiotics decreased significantly. CONCLUSION: In our hospital, multimodal infection control interventions resulted in a significant reduction of CRPA bacteremia, mostly due to the reduction of all classes of antibiotics.

Effectiveness of a Self-Decontaminating Coating Containing Usnic Acid in Reducing Environmental Microbial Load in Tertiary-Care Hospitals.

Surfaces have been implicated in the transmission of pathogens in hospitals. This study aimed to assess the effectiveness of an usnic-acid-containing self-decontaminating coating in reducing microbial surface contamination in tertiary-care hospitals. Samples were collected from surfaces 9 days before coating application, and 3, 10, and 21 days after its application (phases 1, 2, 3, and 4, respectively). Samples were tested for bacteria, fungi, and SARS-CoV2. In phase 1, 53/69 (76.8%) samples tested positive for bacteria, 9/69 (13.0%) for fungi, and 10/139 (7.2%) for SARS-CoV-2. In phase 2, 4/69 (5.8%) samples tested positive for bacteria, while 69 and 139 samples were negative for fungi and SARS-CoV-2, respectively. In phase 3, 3/69 (4.3%) samples were positive for bacteria, 1/139 (0.7%) samples tested positive for SARS-CoV-2, while 69 samples were negative for fungi. In phase 4, 1/69 (1.4%) tested positive for bacteria, while no fungus or SARS-CoV-2 were detected. After the coating was applied, the bacterial load was reduced by 87% in phase 2 (RR = 0.132; 95% CI: 0.108-0.162); 99% in phase 3 (RR = 0.006; 95% CI: 0.003-0.015); and 100% in phase 4 (RR = 0.001; 95% CI: 0.000-0.009). These data indicate that the usnic-acid-containing coating was effective in eliminating bacterial, fungal, and SARS-CoV-2 contamination on surfaces in hospitals.Our findings support the benefit ofan usnic-acid-containing coating in reducing the microbial load on healthcare surfaces.

COVID-19 and Respiratory Virus Co-Infections: A Systematic Review of the Literature.

Τhe COVID-19 pandemic highly impacted the circulation, seasonality, and morbidity burden of several respiratory viruses. We reviewed published cases of SARS-CoV-2 and respiratory virus co-infections as of 12 April 2022. SARS-CoV-2 and influenza co-infections were reported almost exclusively during the first pandemic wave. It is possible that the overall incidence of SARS-CoV-2 co-infections is higher because of the paucity of co-testing for respiratory viruses during the first pandemic waves when mild cases might have been missed. Animal models indicate severe lung pathology and high fatality; nevertheless, the available literature is largely inconclusive regarding the clinical course and prognosis of co-infected patients. Animal models also indicate the importance of considering the sequence timing of each respiratory virus infection; however, there is no such information in reported human cases. Given the differences between 2020 and 2023 in terms of epidemiology and availability of vaccines and specific treatment against COVID-19, it is rational not to extrapolate these early findings to present times. It is expected that the characteristics of SARS-CoV-2 and respiratory virus co-infections will evolve in the upcoming seasons. Multiplex real-time PCR-based assays have been developed in the past two years and should be used to increase diagnostic and infection control capacity, and also for surveillance purposes. Given that COVID-19 and influenza share the same high-risk groups, it is essential that the latter get vaccinated against both viruses. Further studies are needed to elucidate how SARS-CoV-2 and respiratory virus co-infections will be shaped in the upcoming years, in terms of impact and prognosis.

Anaphylaxis rates following mRNA COVID-19 vaccination in children and adolescents: Analysis of data reported to EudraVigilance.

AIM: The present study aimed to estimate the anaphylaxis rates following mRNA COVID-19 vaccination in children and adolescents in Europe. METHODS: We retrieved data on 371 anaphylaxis cases following mRNA COVID-19 vaccination in children ≤ 17 years old notified to EudraVigilance as of October 8, 2022. Overall, 27,120,512 doses of BNT162b2 vaccine and 1,400,300 doses of mRNA-1273 vaccine have been delivered to children during the study period. RESULTS: The overall mean anaphylaxis rate was 12.81 [95% confidence interval (CI): 11.49-14.12] per 106 mRNA vaccine doses [12.14 (95% CI: 6.37-17.91) per 106 doses for mRNA-1273 and 12.84 (95% CI: 11.49-14.19) per 106 doses for BNT162b2]. Children 12-17 years old accounted for 317 anaphylaxis cases, followed by 48 cases in children 3-11 years old, and 6 cases in children 0-2 years old. Children 10-17 years old had a mean anaphylaxis rate of 13.52 (95% CI: 12.03-15.00) cases per 106 mRNA vaccine doses and children 5-9 years old had a mean anaphylaxis rate of 9.51 (95% CI: 6.82-12.20) cases per 106 mRNA vaccine doses. There were two fatalities, both in the 12-17 years age group. The fatal anaphylaxis rate was 0.07 cases per 106 mRNA vaccine doses. CONCLUSIONS: Anaphylaxis is a rare adverse event after receiving an mRNA COVID-19 vaccine in children. Continuous surveillance of serious adverse events is needed to guide vaccination policies as we move towards SARS-CoV-2 endemicity. Larger real-world studies on COVID-19 vaccination in children, using clinical case confirmation, are imperative.

Anaphylactic Reactions to COVID-19 Vaccines: An Updated Assessment Based on Pharmacovigilance Data.

This study aimed at producing an updated assessment of the incidence of anaphylaxis associated with COVID-19 vaccines based on pharmacovigilance data. Anaphylactic reaction and anaphylactic shock data post-COVID-19-vaccination reported from week 52, 2020 to week 1 or week 2, 2023 were collected from the VAERS and EudraVigilance databases, respectively, and analyzed comparatively. Incidence rates were calculated using the corresponding administered vaccine doses as denominators for all licensed vaccines and both platform types (mRNA or vectored). The latest data from the present analysis showed lower anaphylaxis incidence associated with COVID-19 vaccination compared to previous estimates from week 52, 2020 to week 39, 2021 (anaphylactic reaction: 8.96 (95% CI 8.80-9.11)/million doses overall (EEA: 14.19 (95% CI 13.92-14.47)/million/US: 3.17 (95% CI 3.03-3.31)/million); anaphylactic shock: 1.46 (95% CI 1.39-1.52)/million doses overall (EEA: 2.47 (95% CI 2.36-2.58)/million/US: 0.33 (95% CI 0.29-0.38)/million)). Incidence rates varied by vaccine and were higher as captured in EudraVigilance compared to the VAERS and for vectored compared to mRNA vaccines. Most reported cases had a favorable outcome. The extremely rare fatalities (overall rates across continents 0.04 (95% CI 0.03-0.06)/million doses for anaphylactic reaction and 0.02 (95% CI 0.01-0.03)/million vaccine doses for anaphylactic shock) were also associated with vector-rather than mRNA-based vaccines. The diminished incidence of anaphylaxis post-vaccination with COVID-19 vaccines offers assurance about their safety, as does the continuous potential adverse events monitoring through specialized pharmacovigilance databases.

COVID-19 vaccination refusal and suspension of work among healthy healthcare personnel in Italy: A cross-sectional study of their knowledge and attitudes toward vaccinations.

Despite the initial optimistic projections from various countries and the evidence that vaccination against coronavirus disease 2019 (COVID-19) reduces the associated hospitalization rates and mortality, vaccine hesitancy and refusal among healthcare personnel (HCP) became a major public health concern globally. The aim of this survey was to estimate the knowledge about the Italian Vaccination Plan for HCP and attitudes about occupational vaccinations for HCP among Italian HCP who refused COVID-19 vaccination and were suspended from work. A total of 52 HCP participated in the study. Nurses were the prevalent profession among vaccination refusers. About COVID-19, 24 (26.2%) of all responders have been involved in COVID-19 care and 21 (40.4%) had a history of COVID-19. None had received influenza and pneumococcus vaccination in the past. Knowledge of vaccinations recommended for HCP was high, ranging from 75% to 98% by vaccine. Instead, all HCP were against any mandatory vaccination policy for all HCP. Finally, most HCP questioned the expected benefits and safety of vaccines in general, raised issues of mistrust of information provided for authorities and of compliance with their HCP' vaccination recommendations. Our study indicates good knowledge of occupational vaccinations but strong anti-vaccination beliefs among Italian HCP who refused COVID-19 vaccination and were suspended from work.

Effectiveness of full (booster) COVID-19 vaccination against severe outcomes and work absenteeism in hospitalized patients with COVID-19 during the Delta and Omicron waves in Greece.

AIM: We estimated vaccine effectiveness (VE) of full (booster) vaccination against severe outcomes in hospitalized COVID-19 patients during the Delta and Omicron waves. METHODS: The study extended from November 15, 2021 to April 17, 2022. Full vaccination was defined as a primary vaccination plus a booster ≥ 6 months later. RESULTS: We studied 1138 patients (mean age: 66.6 years), of whom 826 (72.6 %) had ≥ 1 comorbidity. Of the 1138 patients, 75 (6.6 %) were admitted to intensive care unit (ICU), 64 (5.6 %) received mechanical ventilation, and 172 (15.1 %) died. There were 386 (33.9 %) fully vaccinated, 172 (15.1 %) partially vaccinated, and 580 (51 %) unvaccinated patients. Unvaccinated patients were absent from work for longer periods compared to partially or fully vaccinated patients (mean absence of 20.1 days versus 12.3 and 17.3 days, respectively; p-value = 0.03). Compared to unvaccinated patients, fully vaccinated patients were less likely to be admitted to ICU [adjusted relative risk (ARR: 0.49; 95 % CI: 0.29-0.84)], mechanically ventilated (ARR: 0.43; 95 % CI: 0.23-0.80), and die (ARR: 0.57; 95 % CI: 0.42-0.78), while they were hospitalized for significantly shorter periods (ARR: 0.79; 95 % CI: 0.70-0.89). The adjusted full VE was 48.8 % (95 % CI: 42.7 %-54.9 %) against ICU admission, 55.4 % (95 % CI: 52.0 %-56.2 %) against mechanical ventilation, and 22.6 % (95 % CI: 7.4 %-34.8 %) against death. For patients with ≥ 3 comorbidities, VE was 56.2 % (95 % CI: 43.9 %-67.1 %) against ICU admission, 60.2 % (95 % CI: 53.7 %-65.4 %) against mechanical ventilation, and 43.9 % (95 % CI: 19.9 %-59.7 %) against death. CONCLUSIONS: Full (booster) COVID-19 vaccination conferred protection against severe outcomes, prolonged hospitalization, and prolonged work absenteeism.

Vaccination programs for children aged up to 18 years in Europe, 2020.

Although all European countries have vaccination policies for children, there are no comprehensive studies of pediatric vaccination programs in Europe. We studied vaccination programs for children in Europe. Vaccinations against diphtheria, tetanus, pertussis, poliomyelitis, Haemophilus influenzae type b, hepatitis B, measles, mumps, rubella, and influenza existed in 42 countries, against human papilloma virus in 41 countries, and against pneumococcus in 40 countries. In addition, the following vaccinations existed: against tuberculosis (35 countries), hepatitis A (33), meningococcus A, C, W, Y (30), rotavirus and varicella (28 countries each), meningococcus B (24), tick-born encephalitis (22), and meningococcus C (16). Mandatory vaccinations are implemented in 21 countries, mainly against diphtheria, tetanus, pertussis, poliomyelitis, H. influenzae type b, hepatitis B, measles, mumps, rubella, tuberculosis, and pneumococcus. There are significant differences among pediatric vaccination programs in Europe regarding number, schedules, indications, and regulatory frame (recommended or mandatory vaccinations). A consensus-based vaccination program for all children is needed.

Antimicrobial Effectiveness of an Usnic-Acid-Containing Self-Decontaminating Coating on Underground Metro Surfaces in Athens.

(1) Background: Surfaces have been implicated in the transmission of infections. We aimed to assess how effective an usnic-acid-containing self-decontaminating coating was on the surfaces of the Athens underground metro. (2) Methods: Two samples were collected from each of 60 surfaces of a station and a wagon before the application of the coating and 9 and 20 days after, and they were tested for bacteria, fungi, and SARS-CoV-2 using conventional microbiological and molecular methods. Bacteria and fungi growth were expressed in colony forming units (CFUs)/102cm2. (3) Results: Before the application of the coating, 50% of the samples tested positive for the targeted microbes: 91.7% for bacteria, 18.3% for fungi, and 8.3% for SARS-CoV-2. After nine days, 3.3% of the samples tested positive for bacteria and 6.6% after 20 days. The average amount of bacteria before the coating was applied was 8.5 CFU/102cm2 compared to 0 and 0 CFU/102cm2 after application (100% and 95% reduction); all samples collected after the application were negative for SARS-CoV-2 and fungi (100% reduction). (4) Conclusion: An usnic-acid-containing self-decontaminating coating was highly effective in eliminating bacterial, fungal, and SARS-CoV-2 contamination of surfaces in the underground metro.

Association between COVID-19 vaccination status, time elapsed since the last vaccine dose, morbidity, and absenteeism among healthcare personnel: A prospective, multicenter study.

AIM: We assessed the impact of COVID-19 vaccination status and time elapsed since the last vaccine dose on morbidity and absenteeism among healthcare personnel (HCP) in the context of a mandatory vaccination policy. METHODS: We followed 7592 HCP from November 15, 2021 through April 17, 2022. Full COVID-19 vaccination was defined as a primary vaccination series plus a booster dose at least six months later. RESULTS: There were 6496 (85.6 %) fully vaccinated, 953 (12.5 %) not fully vaccinated, and 143 (1.9 %) unvaccinated HCP. A total of 2182 absenteeism episodes occurred. Of 2088 absenteeism episodes among vaccinated HCP with known vaccination status, 1971 (94.4 %) concerned fully vaccinated and 117 (5.6 %) not fully vaccinated. Fully vaccinated HCP had 1.6 fewer days of absence compared to those not fully vaccinated (8.1 versus 9.7; p-value < 0.001). Multivariable regression analyses showed that full vaccination was associated with shorter absenteeism compared to not full vaccination (OR: 0.56; 95 % CI: 0.36-0.87; p-value = 0.01). Compared to a history of ≤ 17.1 weeks since the last dose, a history of > 17.1 weeks since the last dose was associated with longer absenteeism (OR: 1.22, 95 % CI:1.02-1.46; p-value = 0.026) and increased risk for febrile episode (OR: 1.33; 95 % CI: 1.09-1.63; p-value = 0.004), influenza-like illness (OR: 1.53, 95 % CI: 1.02-2.30; p-value = 0.038), and COVID-19 (OR: 1.72; 95 % CI: 1.24-2.39; p-value = 0.001). CONCLUSIONS: The COVID-19 pandemic continues to impose a considerable impact on HCP. The administration of a vaccine dose in less than four months before significantly protected against COVID-19 and absenteeism duration, irrespective of COVID-19 vaccination status. Defining the optimal timing of boosters is imperative.