Clinical Features of Patients Presenting to the Emergency Department With Cardiovascular Adverse Reactions After COVID-19 mRNA Vaccination

BackgroundSince the implementation of the nationwide coronavirus disease 2019 (COVID-19) vaccination campaign, emergency departments (EDs) have had an increasing number of patients reporting postvaccination cardiovascular adverse effects. We investigated the clinical features of patients who visited the ED for cardiovascular adverse reactions after COVID-19 mRNA vaccination.MethodsWe conducted a retrospective observational study in two EDs. Patients with cardiovascular adverse reactions after COVID-19 mRNA vaccination who visited EDs between June 1, 2021, and October 15, 2021, were selected. The clinical data of these patients were collected by reviewing medical records.ResultsAmong 683 patients, 426 (62.4%) were female. The number of patients in their 20s was the highest (38.9% of males, 28.2% of females) (P < 0.001). More patients visited the ED for adverse reactions following the first vaccine dose than following the second dose (67.6% vs. 32.2%). Chief complaints were chest pain/discomfort (74.4%), dyspnea (14.3%) and palpitation (11.3%). The final diagnosis was a nonspecific cause (63.1%), and 663 (97.1%) patients were discharged from the ED. The admission rate was higher in males than in females (3.9% vs. 1.9%). Myocarditis was diagnosed in four males, who showed mild clinical progression and were discharged within 5 hospital days.ConclusionMost patients who visited the ED with cardiovascular adverse reactions were discharged from the ED, but some were admitted for other medical diseases as well as adverse vaccine reactions. Therefore, further surveillance and a differential diagnosis of cardiovascular adverse events after COVID-19 mRNA vaccination should be considered by emergency physicians.     

Vaccination intention among healthcare workers during the first wave of the coronavirus disease 2019 pandemic in relation to knowledge: a cross-sectional study in Croatia,Slovenia, Serbia,and Poland

AimTo analyze SARS-CoV-2 vaccination intention and acceptance in relation to the knowledge about coronavirus disease 2019 (COVID-19) among healthcare workers (HCWs) in Croatia, Slovenia, Serbia, and Poland.MethodsIn spring 2020, an online survey was distributed among HCWs by using snowball sampling. The questionnaire was fully completed by 623 respondents: 304 from Croatia, 86 from Slovenia, 90 from Serbia, and 143 from Poland. The survey collected data on demographic characteristics (age, gender, education), vaccination acceptance, and knowledge about COVID-19.ResultsA total of 31% of respondents declared their intention to be vaccinated when a vaccine against COVID-19 is available, and 45% were undecided. Vaccination intention was associated with age, educational level, and knowledge about the pandemic, and differed significantly among the countries. Younger HCWs (18-25 years) and those with higher education more frequently expressed vaccination acceptance. Vaccination acceptance score was not associated with gender.ConclusionsHCWs with higher knowledge were more likely to express vaccination intention. Improving the knowledge about COVID-19 and increasing HCWs'' education might also increase vaccination acceptance among HCWs, and consequently in the general population.

When in early March 2020, the SARS-CoV-2 virus began to spread in Europe, the governments of Croatia, Slovenia, Serbia, and Poland relatively quickly imposed containment measures, including a closure of kindergartens and schools, and a ban on public life. The measures seemed to be successful, as in the first wave of the pandemic these countries had lower COVID-19 infection and death rates than some Western European countries such as Italy, France, Spain, and the United Kingdom (1). It soon became clear that, in addition to prevention, diagnosis, and treatment, the pandemic can be limited globally only by the introduction of vaccines against COVID-19 (2). The success of a vaccination program depends on the uptake rates in the population, especially among health care workers (HCWs) (3). Better knowledge about the disease and higher perceived severity of COVID-19 have been shown to increase vaccine acceptance (4).HCWs play an important role as health educators and can help in disease control by disseminating accurate information in communities. According to the theory of knowledge, attitude, and practice, successful disease control requires good knowledge of the disease (5). HCWs'' lack of such knowledge can delay treatment and lead to rapid spread of infection (6,7). Indeed, HCWs were shown to have inadequate knowledge about COVID-19 (8).HCWs have a higher risk of becoming infected with COVID-19 than the general population (3,9,10) and are potential transmitters of the virus in the clinical setting. However, they can also help the lay population understand and accept vaccination. In Southeast Asia, HCWs had higher acceptance of COVID-19 vaccination than the general population, due to a higher perceived risk of COVID-19 infection (11). Chinese HCWs had higher willingness to receive future vaccination compared with lay population (12). Because HCWs are the most important sources of information and the strongest authority when it comes to vaccination decisions (13-15), their opinions and vaccination intentions should be assessed, and the relation between key sociodemographic factors and vaccination intentions should be investigated.Due to the importance of HCWs'' vaccination uptake during the COVID-19 pandemic in Central and Eastern Europe, this study analyzed HCWs'' vaccination acceptance in Croatia, Slovenia, Serbia, and Poland in relation to their knowledge about COVID-19. Based on the findings of previous research on influenza vaccination uptake (17), we hypothesized that the countries would significantly differ in COVID-19 vaccination intention and acceptance among HCWs and that vaccination acceptance would be influenced by gender, education, knowledge, and attitudes.     

Risk categorization and outcomes among healthcare workers exposed to COVID-19: A cohort study from a Thai tertiary-care center

BackgroundA risk categorization tool for healthcare workers (HCWs) exposed to COVID-19 is crucial for preventing COVID-19 transmission and requires validation and modification according to local context.MethodsFrom January to December 2021, a prospective cohort study was conducted among Thai HCWs to evaluate the performance of the specifically-created risk categorization tool, which classified HCWs into low-risk (LR), intermediate-risk (IR), and high-risk (HR) groups based on types of activities, duration of exposure, and protective methods used during exposure. Subsequent measures were determined for the HCWs based on the risk categories.Results1891 HCWs were included; 52%, 25% and 23% were LR, IR, and HR, respectively. COVID-19 was diagnosed in 1.3%, 5.1% and 27.3% of LR, IR and HR HCWs, respectively (P <0.001). Independent factors associated with COVID-19 were household or community exposure [adjusted odds ratio (aOR), 1588.68; P <0.001), being HR (aOR, 11.94; P <0.001), working at outpatient departments (aOR, 2.54; P <0.001), and no history of COVID-19 vaccination (aOR, 2.05; P = 0.01). The monthly rates of COVID-19 among LR, IR, and HR HCWs significantly decreased after the incremental rate of full vaccination. In-hospital transmission between HCWs occurred in 8% and was mainly due to eating at the same table.ConclusionThe study risk categorization tool can differentiate risks of COVID-19 among the HCWs. Prevention of COVID-19 should be focused on HCWs with the identified risk factors and behaviors associated with COVID-19 development and encouraging receipt of full vaccination.     

Effectiveness of mRNA-BNT162b2, mRNA-1273, and ChAdOx1 nCoV-19 vaccines against COVID-19 in healthcare workers: an observational study using surveillance data

ObjectivesHealthcare workers (HCWs) at increased risk of coronavirus disease 2019 (COVID-19) were among the primary targets for vaccine campaigns. We aimed to estimate the protective efficacy of the first three COVID-19 vaccines available in Western Europe.MethodsWe merged two prospective databases that systematically recorded, in our institution: (a) HCWs positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by RT-PCR on nasopharyngeal samples, and (b) HCWs who received at least one dose of COVID-19 vaccine. We excluded HCWs with SARS-CoV-2 infection during the 6 months prior to the study. HCWs were categorized as non-vaccinated if they received no vaccine and until the first injection +13 days, partially vaccinated from the first injection +14 days to the second injection +13 days, and fully vaccinated thereafter.ResultsOf the 8165 HCWs employed in our institution, 360 (4.4%) tested positive for SARS-CoV-2 by RT-PCR during the study period (4th January to 17th May 2021). Incidence was 9.1% (8.2–10.0) in non-vaccinated HCWs, 1.2% (0.7–1.9) after one dose of ChAdOx1 nCoV-19, 1.4% (0.6–2.3) and 0.5% (0.1–1.0) after one and two doses of mRNA BNT162b2, 0.7% (0.1–1.9) and 0% after one and two doses of mRNA-1273 (p < 0.0001). Vaccine effectiveness (Cox model) was estimated at, respectively, 86.2% (76.5–91.0), 38.2% (6.3–59.2), and 49.2% (19.1–68.1) 14 days after the first dose for ChAdOx1 nCoV-19, mRNA-1273, and mRNA-BNT162b2, and 100% (ND) and 94.6% (61.0–99.2) 14 days after the second dose for mRNA-1273 and mRNA-BNT162b2.ConclusionsIn this real-world study, the observed effectiveness of COVID-19 vaccines in HCWs was in line with the efficacy reported in pivotal randomized trials.     

Adverse Events Following Immunization Associated with Coronavirus Disease 2019 Vaccination Reported in the Mobile Vaccine Adverse Events Reporting System

BackgroundVaccination against coronavirus disease 2019 (COVID-19) is underway globally to prevent the infection caused by the severe acute respiratory syndrome coronavirus 2. We aimed to investigate the adverse events following immunization (AEFIs) for COVID-19 among healthcare workers (HCWs).MethodsThis was a retrospective study of the AEFIs associated with the first dose of the ChAdOx1 nCoV-19 vaccine at the Kosin University Gospel Hospital from March 3 to March 22, 2021. We investigated the systemic and local adverse events during the 7 days following the vaccination using the Mobile Vaccine Adverse Events Reporting System (MVAERS) developed by our hospital.ResultsA total of 1,503 HCWs were vaccinated, and the data of 994 HCWs were reported in the MVAERS. The most commonly reported AEFIs were tenderness at the injection site (94.5%), fatigue (92.9%), pain at the injection site (88.0%), and malaise (83.8%). The severity of most AEFIs was mild-to-moderate, and the severity and number of AEFIs were less in the older age group. There were no serious events requiring hospitalization, and most AEFIs improved within a few days.ConclusionThe AEFIs associated with the ChAdOx1 nCoV-19 vaccine were tolerable, and the use of the MVAERS was helpful in monitoring the AEFIs. The use of MVAERS will help in sharing accurate and ample information about vaccination against COVID-19.     

Effectiveness of MRNA booster vaccine among healthcare workers in New York City during the Omicron surge,December 2021 to January 2022

ObjectiveTo describe effectiveness of mRNA vaccines by comparing 2-dose (2D) and 3-dose (3D) healthcare worker (HCW) recipients in the setting of Omicron variant dominance. Performance of 2D and 3D vaccine series against SARS-CoV-2 variants and the clinical outcomes of HCWs may inform return-to-work guidance.MethodsIn a retrospective study from December 15, 2020 to January 15, 2022, SARS-CoV-2 infections among HCWs at a large tertiary cancer centre in New York City were examined to estimate infection rates (aggregated positive tests / person-days) and 95% CIs over the Omicron period in 3D and 2D mRNA vaccinated HCWs and were compared using rate ratios. We described the clinical features of post-vaccine infections and impact of prior (pre-Omicron) COVID infection on vaccine effectiveness.ResultsAmong the 20857 HCWs in our cohort, 20,660 completed the 2D series with an mRNA vaccine during our study period and 12461 had received a third dose by January 15, 2022. The infection rate ratio for 3D versus 2D vaccinated HCWs was 0.667 (95% CI 0.623, 0.713) for an estimated 3D vaccine effectiveness of 33.3% compared to two doses only during the Omicron dominant period from December 15, 2021 to January 15, 2022. Breakthrough Omicron infections after 3D + 14 days occurred in 1,315 HCWs. Omicron infections were mild, with 16% of 3D and 11% 2D HCWs being asymptomatic.DiscussionStudy demonstrates improved vaccine-derived protection against COVID-19 infection in 3D versus 2D mRNA vaccinees during the Omicron surge. The advantage of 3D vaccination was maintained irrespective of prior COVID-19 infection status.     

Long-term evolution of humoral immune response after SARS-CoV-2 infection

ObjectiveWe aimed to characterize the evolution of humoral immune response up to 1 year after SARS-CoV-2 infection in healthcare workers (HCWs) during the first wave of COVID-19 in Paris.MethodsSerum samples from 92 HCWs were tested at month 0 (M0), M6, and M12 after SARS-CoV-2 infection for IgG targeting the nucleocapsid (N), IgG targeting the receptor-binding domain (RBD) of spike (S) protein, IgA targeting S, and anti-RBD neutralizing antibodies. After M6, 46 HCWs received a single dose of COVID-19 vaccine.ResultsWe observed a significant decrease in all SARS-CoV-2 immunologic markers at M6 post-infection: median decreases were 0.26 log binding antibody units/mL (M0: 1.9 (interquartile range (IQR) 1.47–2.27); M6: 1.64 (IQR 1.22–1.92)) for anti-RBD IgG; 4.10 (index) (M0: 4.94 (IQR 2.72–6.82); M6: 0.84 (IQR 0.25–1.55)) for anti-N IgG; 0.64 (index) (M0: 2.50 (IQR 1.18–4.62); M6: 1.86 (IQR 0.85–3.54)) for anti-S IgA; and 24.4% (M0: 66.4 (IQR 39.7–82.5); M6: 42.0 (IQR 16.8–68.8)) inhibition activity for the RBD neutralizing antibodies. Between M6 and M12, anti-RBD IgG level, anti-S IgA index, and anti-RBD neutralizing activity significantly increased among COVID-19 vaccinated HCWs, whereas they remained stable among unvaccinated HCWs. Anti-N IgG index significantly decreased between M6 and M12 among both vaccinated (median: 0.73 (IQR 0.23–1.11) at M6 and 0.52 (IQR 0.20–0.73) at M12) and unvaccinated HCWs (median: 0.79 (IQR 0.21–4.67) at M6 and 0.34 (IQR 0.24–2.78) at M12).DiscussionA steady decline in the anti-N IgG response was observed during the first year after SARS-CoV-2 infection among HCWs, whereas the anti-RBD IgG and the anti-S IgA responses remained stable and could be enhanced by COVID-19 vaccination.     

A cluster of health care workers with COVID-19 pneumonia caused by SARS-CoV-2

BackgroundThe current outbreak of coronavirus disease 2019 (COVID-19) caused by Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Wuhan, Hubei, China, spreads across national and international borders.MethodsWe prospectively collected medical records of 14 health care workers (HCWs) who were infected with SARS-CoV-2, in neurosurgery department of Wuhan Union Hospital, China.ResultsAmong the 14 HCWs, 12 were conformed cases, the other 2 were suspected cases. Most of them were either exposed to the two index patients or infected coworkers, without knowing they were COVID-19 patients. There were 4 male and 10 female infected HCWs in this cohort, whose mean age was 36 years (SD, 6 years). The main symptoms included myalgia or fatigue (100%), fever (86%) and dry cough (71%). On admission, 79% of infected HCWs showed leucopenia and 43% lymphopenia. Reduced complement C3 could be seen in 57% of the infected HCWs and IL-6 was significantly elevated in 86% of them. The proportion of lymphocytes subsets, concentrations of immunoglobulins, complement C4, IL-2, IL-4, IL-10, TNF-α and IFN-γ were within normal range in these 14 infected HCWs. The most frequent findings on pulmonary computed tomographic images were bilateral multifocal ground-glass opacifications (86%).ConclusionsHuman-to-human transmission of COVID-19 pneumonia has occurred among HCWs, and most of these infected HCWs with confirmed COVID-19 are mild cases. Our data suggest that in the epidemic area of COVID-19, stringent and urgent surveillance and infection-control measures should be implemented to protect doctors and nurses from COVID-19 infection.     

Pediatric Emergency Department Utilization and Coronavirus Disease in Daegu,Korea

BackgroundLimited data exist on children''s utilization of the emergency department (ED) in the ongoing coronavirus disease 2019 (COVID-19) pandemic. Thus, we aimed to examine ED utilization among pediatric patients and the impact of COVID-19 in one large city affected by the outbreak.MethodsThis retrospective study included data from six EDs in Daegu, Korea. We compared the demographic and clinical data of patients presenting to the ED during the COVID-19 pandemic (February 1st–June 30th 2020) with those of patients who visited the ED in this period during 2018 and 2019.ResultsFewer patients, particularly children visited the EDs during the study period in 2020 than those in the previous (2018/2019) year period: the number of adult patient decreased by 46.4% and children by 76.9%. Although the number of patients increased from the lowest point of the decrease in March 2020, the number of pediatric patients visiting the ED remained less than half (45.2%) in June 2020 compared with that of previous years. The proportion of patients with severe conditions increased in adults, infants, and school-aged children, and consequently resulted in increased ambulance use and higher hospitalization rates. Fewer infants and young children but more school-aged children visited the ED with febrile illnesses in 2020 than in 2018/2019.ConclusionThe COVID-19 pandemic has led to a substantial decrease in pediatric ED utilization. These findings can help reallocate human and material resources in the EDs during infectious disease outbreaks.     

Changes in Anxiety Level and Personal Protective Equipment Use Among Healthcare Workers Exposed to COVID-19

BackgroundThe relationship between changes in anxiety levels and personal protective equipment (PPE) use is yet to be evaluated. The present study assessed this relationship among healthcare workers (HCWs) involved in the care of patients with coronavirus disease 2019 (COVID-19).MethodsAn online survey was conducted in a municipal hospital with 195 nationally designated negative pressure isolation units in Korea. Anxiety level was measured using the self-rating anxiety scale (SAS), and changes in anxiety levels were assessed based on the time when COVID-19 vaccine was introduced in March 2021 in Korea. Monthly PPE usage between June 2020 and May 2021 was investigated.ResultsThe mean SAS score (33.25 ± 5.97) was within normal range and was lower than those reported in previous studies conducted before COVID-19 vaccination became available. Among the 93 HCWs who participated, 64 (68.8%) answered that their fear of contracting COVID-19 decreased after vaccination. The number of coveralls used per patient decreased from 33.6 to 0. However, a demand for more PPE than necessary was observed in situations where HCWs were exposed to body fluids and secretions (n = 38, 40.9%). Excessive demand for PPE was not related to age, working experience, or SAS score.ConclusionAnxiety in HCWs exposed to COVID-19 was lower than it was during the early period of the pandemic, and the period before vaccination was introduced. The number of coveralls used per patient also decreased although an excessive demand for PPE was observed.     

Investigation of an outbreak of symptomatic SARS-CoV-2 VOC 202012/01-lineage B.1.1.7 infection in healthcare workers,Italy

ObjectivesIn December 2020, Italy began a national immunization campaign using the BNT162b2 coronavirus disease 2019 (COVID-19) mRNA vaccine, prioritizing healthcare workers (HCWs). Immune serum from vaccinated subjects seems (largely) to retain titres of neutralizing antibodies, even against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) VOC 202012/01-lineage B.1.1.7. Here, we describe an outbreak of SARS-CoV-2 lineage B.1.1.7 infection in three HCWs in a hospital setting; two of the HCWs were fully vaccinated (i.e. had received two doses).MethodsTwo physicians and one nurse working on the same shift on 20th February 2021 were involved in the outbreak. Real-time PCR, antigen tests, and serological tests for the IgG anti-spike protein of SARS-CoV-2 were performed, along with whole-genome sequencing (WGS).ResultsSARS-CoV-2 infection was confirmed in all three HCWs; all presented with mild symptoms of COVID-19. The two physicians were fully vaccinated with BNT162b2 vaccine, with the second dose administered 1 month before symptom onset. Both had high titres of IgG anti-spike antibodies at the time of diagnosis. WGS confirmed that all virus strains were VOC 202012/01-lineage B.1.1.7, suggesting a common source of exposure. Epidemiological investigation revealed that the suspected source was a SARS-CoV-2-positive patient who required endotracheal intubation due to severe COVID-19. All procedures were carried out using a full suite of personal protective equipment (PPE).ConclusionsThis mini-outbreak highlights some important issues about the efficacy of vaccines against transmission of SARS-CoV-2 variants, the high risk of exposure among HCWs, and the need for optimized implementation of PPE in hospitals. The wide circulation of VOC 202012/01 in Europe and Italy highlights the need to improve surveillance and genetic sequencing.     

Bacillus Calmette-Guérin vaccine to reduce healthcare worker absenteeism in COVID-19 pandemic,a randomized controlled trial

ObjectivesThe COVID-19 pandemic increases healthcare worker (HCW) absenteeism. The bacillus Calmette-Guérin (BCG) vaccine may provide non-specific protection against respiratory infections through enhancement of trained immunity. We investigated the impact of BCG vaccination on HCW absenteeism during the COVID-19 pandemic.MethodsHCWs exposed to COVID-19 patients in nine Dutch hospitals were randomized to BCG vaccine or placebo in a 1:1 ratio, and followed for one year using a mobile phone application. The primary endpoint was the self-reported number of days of unplanned absenteeism for any reason. Secondary endpoints included documented COVID-19, acute respiratory symptoms or fever. This was an investigator-funded study, registered at ClinicalTrials.gov (NCT03987919).ResultsIn March/April 2020, 1511 HCWs were enrolled. The median duration of follow-up was 357 person-days (interquartile range [IQR], 351 to 361). Unplanned absenteeism for any reason was observed in 2.8% of planned working days in the BCG group and 2.7% in the placebo group (adjusted relative risk 0.94; 95% credible interval, 0.78–1.15). Cumulative incidences of documented COVID-19 were 14.2% in the BCG and 15.2% in the placebo group (adjusted hazard ratio (aHR) 0.94; 95% confidence interval (CI), 0.72–1.24). First episodes of self-reported acute respiratory symptoms or fever occurred in 490 (66.2%) and 443 (60.2%) participants, respectively (aHR: 1.13; 95% CI, 0.99–1.28). Thirty-one serious adverse events were reported (13 after BCG, 18 after placebo), none considered related to study medication.ConclusionsDuring the COVID-19 pandemic, BCG-vaccination of HCW exposed to COVID-19 patients did not reduce unplanned absenteeism nor documented COVID-19.     

Virological and serological kinetics of SARS-CoV-2 Delta variant vaccine breakthrough infections: a multicentre cohort study

ObjectivesHighly effective vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed but variants of concerns are worrisome, especially B.1.617.2 (Delta) which has rapidly spread across the world. We aim to study if vaccination alters virological and serological kinetics in breakthrough infections.MethodsWe conducted a multicentre retrospective cohort study of patients in Singapore who had received a licensed mRNA vaccine and been admitted to hospital with B.1.617.2 SARS-CoV-2 infection. We compared clinical features, virological and serological kinetics (anti-nucleocapsid, anti-spike and surrogate virus neutralization titres) between fully vaccinated and unvaccinated individuals.ResultsOut of 218 individuals with B.1.617.2 infection, 84 received an mRNA vaccine of which 71 were fully vaccinated, 130 were unvaccinated and four received a non-mRNA vaccine. Despite significantly older age in the vaccine breakthrough group, only 2.8% (2/71) developed severe COVID-19 requiring oxygen supplementation compared with 53.1% (69/130) in the unvaccinated group (p < 0.001). Odds of severe COVID-19 following vaccination were significantly lower (adjusted odds ratio 0.07 95% CI 0.015–0.335, p 0.001). PCR cycle threshold values were similar between vaccinated and unvaccinated groups at diagnosis, but viral loads decreased faster in vaccinated individuals. Early, robust boosting of anti-spike protein antibodies was observed in vaccinated patients; however, these titres were significantly lower against B.1.617.2 than the wildtype vaccine strain.DiscussionThe mRNA vaccines are highly effective at preventing symptomatic and severe COVID-19 associated with B.1.617.2 infection. Vaccination is associated with faster decline in viral RNA load and a robust serological response. Vaccination remains a key strategy for control of the COVID-19 pandemic.     

Pediatric and Parents' Attitudes Towards COVID-19 Vaccines and Intention to Vaccinate for Children

BackgroundCoronavirus disease 2019 (COVID-19) vaccination is necessary to reach herd immunity and essential for mitigating the spread of the pandemic. In May 2021, the US FDA and the EU have expanded the emergency use authorization for a COVID-19 vaccine to children aged 12 to 15. The aim of this study was to investigate parental acceptability of COVID-19 vaccination for their children, factors affecting their acceptability, and children''s perceptions of COVID-19 vaccines in Republic of Korea.MethodsWe conducted a questionnaire survey at two tertiary hospitals from May 25, 2021 to June 3, 2021. Subjects were parents having children under 18 years and children aged 10–18 years.ResultsTwo hundred twenty-six parents and 117 children aged 10–18 years were included in the final analysis. Overall, 76.5% and 64.2% of parents intended to get vaccinated against COVID-19 and intended to have their children vaccinated, respectively. However, only 49.6% of children responded that they would get COVID-19 vaccination. In the multivariate analysis, high confidence in the safety of COVID-19 vaccines (adjusted odds ratio [AOR], 4.87; 95% confidence interval [CI], 1.32–24.12), parents'' willingness to vaccinate themselves (AOR, 19.42; 95% CI, 6.85–64.00), and awareness of the need to vaccinate children against COVID-19 (AOR, 13.15; 95% CI, 4.77–41.27) were associated with positive factors intention to vaccinate their children.ConclusionThis study provides insight into how parents think about the COVID-19 vaccine for their children in South Korea. Our findings could be referenced in establishing a policy for childhood COVID-19 vaccination in the future.     

Association of the COVID-19 Pandemic and Low-rescue Suicide Attempts in Patients Visiting the Emergency Department after Attempting Suicide

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic may increase the total number of suicide attempts and the proportion of low-rescue attempts. We investigated the factors affecting low-rescue suicide attempts using the risk-rescue rating scale (RRRS) among patients who visited the emergency department (ED) after attempting suicide before or during the COVID-19 pandemic.MethodsWe retrospectively investigated suicide attempts made by patients who visited our ED from March 2019 to September 2020. Patients were classified into two groups based on whether they attempted suicide before or during the COVID-19 pandemic. Data on demographic variables, psychiatric factors, suicide risk factors and rescue factors were collected and compared.ResultsA total of 518 patients were included in the study, 275 (53.1%) of whom attempted suicide during the COVID-19 pandemic. The proportion of patients who made low-rescue suicide attempts differed before and during the COVID-19 pandemic (37.1% vs. 28.8%) (P = 0.046). However, the proportions of patients who made high-risk suicide attempts and high-lethality suicide attempts did not significantly differ between the two periods. The independent risk factors for low-rescue suicide attempts were age and the COVID-19 pandemic (odds ratio [OR], 1.02; 95% confidence interval [CI], 1.00–1.03; P = 0.006) (OR, 1.52; 95% CI, 1.03–2.25; P = 0.034).ConclusionThe COVID-19 pandemic was associated with low-rescue suicide attempts in patients visiting the ED after attempting suicide. Thus, we need to consider the implementation of measures to prevent low-rescue suicide attempts during similar infectious disease crises.     

Extremely low prevalence of asymptomatic COVID-19 among healthcare workers caring for COVID-19 patients in Israeli hospitals: a cross-sectional study

ObjectivesWe aimed to compare the prevalence of asymptomatic coronavirus disease 19 (COVID-19) among clinical staff in designated COVID-19 units versus that among staff in similar units with no known or suspected COVID-19 patients.MethodsWe conducted a cross-sectional survey of healthcare workers (HCWs) in eight Israeli general hospitals. The survey involved a questionnaire and a PCR test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We surveyed HCWs in COVID-19 units and comparison units (internal medicine and cardiology) between 30th April and 7th May 2020.ResultsThere were 522 participants: 291 from COVID-19 units and 231 from comparison units. Only one participant (0.2%, 95%CI: 0.005–1.1%)—an asymptomatic nurse on a COVID-19 unit—tested positive for SARS-CoV-2. In participating COVID-19 units there were two symptomatic HCWs with confirmed COVID-19 in the 2 weeks before the survey; both were infected by contact with a co-worker outside of the COVID-19 unit.ConclusionsThe low prevalence of asymptomatic COVID-19 among HCWs, coupled with an absence of symptomatic COVID-19 acquired during patient care, suggest that Israel's national guidelines for personal protective equipment, which are consistent with those of the World Health Organization, adequately protect HCWs.     

Analyses of Confirmed COVID-19 Cases Among Korean Military Personnel After Mass Vaccination

BackgroundThe military was one of the first groups in Korea to complete mass vaccination against the coronavirus disease 2019 (COVID-19) due to their high vulnerability to COVID-19. To confirm the effect of mass vaccination, this study analyzed the patterns of confirmed cases within Korean military units.MethodsFrom August 1 to September 15, 2021, all epidemiological data regarding confirmed COVID-19 cases in military units were reviewed. The number of confirmed cases in the units that were believed to have achieved herd immunity (i.e., ≥ 70% vaccination) was compared with the number of cases in the units that were not believed to have reached herd immunity (< 70% vaccination). Additionally, trends in the incidence rates of COVID-19 in the military and the entire Korean population were compared.ResultsBy August 2021, 85.60% of military personnel were fully vaccinated. During the study period, a total of 174 COVID-19 cases were confirmed in the 39 units. More local transmission (herd immunity group vs. non-herd immunity group [%], 1 [0.91] vs. 39 [60.94]) and hospitalizations (12 [11.01] vs. 13 [27.08]) occurred in the units that were not believed to have achieved herd immunity. The percentage of fully vaccinated individuals among the confirmed COVID-19 cases increased over time, possibly due to the prevalence of the delta variant. Nevertheless, the incidence rate remained lower in military units than in the general Korean population.ConclusionAfter completing mass vaccination, the incidence rates of COVID-19 infection in the military were lower than those in the national population. New cluster infections did not occur in vaccinated units, thereby suggesting that herd immunity has been achieved in these military units. Further research is needed to determine the extent to which levels of non-pharmacological intervention can be reduced in the future.     

Changes in Clinical Characteristics among Febrile Patients Visiting the Emergency Department before and after the COVID-19 Outbreak

PurposeConsidering the risk of coronavirus disease (COVID-19) transmission through infected droplets, emergency department (ED) operations in response to febrile patients should be planned. We investigated the general and clinical characteristics of febrile patients visiting the ED and changes in admission rates via the ED during the COVID-19 outbreak.Materials and MethodsWe performed a retrospective analysis of prospectively collected patients who visited 402 EDs in the Republic of Korea with febrile symptoms between January 27 and May 31, 2020 and compared them to those enrolled before the COVID-19 outbreak. The primary outcome was admission rate; the secondary outcome was length of stay (LOS) in the ED.ResultsIn total, 266519 patients had febrile symptoms at ED presentation after the COVID-19 outbreak. In 2019, before the outbreak, there were 437762 patients. The rate of ED visits among pediatric patients (aged <15 years) decreased to 21.4% after the COVID-19 outbreak, compared with 41.8% in 2019. The proportion of patients admitted after ED management was higher after the outbreak (31.3%) than before (25.2%). The adjusted odds ratio for admission was 1.04 (95% confidence interval: 1.02–1.05) after the outbreak. Compared to before the COVID-19 outbreak, the median ED LOS increased by 16 min after the outbreak.ConclusionThis study confirmed that admission rates and ED LOS increased for febrile patients visiting the ED after the COVID-19 outbreak. This could provide evidence for developing ED-related strategies in response to the ongoing COVID-19 outbreak and other infectious disease pandemics.     

The effect of a third BNT162b2 vaccine on breakthrough infections in health care workers: a cohort analysis

ObjectivesIn August 2021, 6 months after mass vaccination of the Israeli population with the two-dose BNT162b2 mRNA vaccine, a surge of coronavirus disease 2019 infections, mostly from the delta variant, appeared also among the vaccinated. In response, the Israeli Ministry of Health initiated a booster (third dose) vaccination program. We assessed the protective effect of the third dose among health care workers (HCWs).MethodsInfections with severe acute respiratory syndrome coronavirus 2 are monitored systematically among HCWs at the Hadassah tertiary care medical centre in Jerusalem, Israel. In this cohort, we included breakthrough infections, defined as those occurring >180 days since the second vaccine dose. The follow-up period lasted 120 days. We compared infection rates between HCWs who received the booster dose and those who received only the two-dose regimen.ResultsThe rate of breakthrough infections among HCWs who received only the two-dose regimen was 21.4% (85 of 398). The rate in the boosted group was 0.7% (35/4973; relative risk 30, 95% CI 20-50). Those results were seen in all age groups.DiscussionThe significantly lower rate of breakthrough infections in boosted HCWs indicates substantial protection by a third vaccine dose.     

Adverse Reactions Following the First Dose of ChAdOx1 nCoV-19 Vaccine and BNT162b2 Vaccine for Healthcare Workers in South Korea

BackgroundWe performed a prospective survey on the adverse reactions following the first dose of two types of vaccines against coronavirus disease 2019 (COVID-19) in healthcare workers (HCWs) in South Korea.MethodsHCWs at a tertiary referral hospital in Seoul, South Korea, received a chimpanzee adenovirus-vectored vaccine (ChAdOx1 nCoV-19) or an mRNA-based vaccine (BNT162b2) between March 5 and March 26, 2021. The HCWs were asked to report adverse reactions through a mobile self-report questionnaire for three days after vaccination.ResultsA total of 7,625 HCWs received the first dose of ChAdOx1 or BNT162b2 vaccine during the study period. Of them, 5,866 (76.9%) HCWs (ChAdOx1, n = 5,589 [95.3%]; BNT162b2, n = 277 [4.7%]) participated at least once in the survey, of whom 77% were female and 86% were younger than 50 years. The overall adverse reaction rate was 93% in the ChAdOx1 group and 80% in the BNT162b2 group (P < 0.001). Both local and systemic reactions were more commonly reported in the ChAdOx1 group, and the difference was larger in systemic reactions such as fever and fatigue. In the ChAdOx1 group, the incidence of adverse reactions was significantly higher in females and those in the younger age groups, while the BNT162b2 group showed such difference according to age.ConclusionIn our prospective survey, vaccine-associated adverse reactions were more commonly reported in the ChAdOx1 group than in the BNT162b2 group. Females and younger age groups experienced vaccine-associated adverse reactions more frequently.