Several studies reported hematological abnormalities after vaccination against the coronavirus disease 2019 . We evaluated the association between COVID-19 vaccines (CoronaVac and BNT162b2) and hematological abnormalities.We conducted nested case-control and self-controlled case series analyses using the data from the Hong Kong Hospital Authority and the Department of Health, HKSAR.Outcomes of interest were thrombocytopenia, leukopenia, and neutropenia. Adjusted odds ratios (aORs), incidence rate ratios (IRRs), and 95% confidence intervals (CIs) were estimated using conditional logistic regression. In total, 1 643 419 people received COVID-19 vaccination (738 609 CoronaVac; 904 810 BNT162b2). We identified 457 and 422 cases after CoronaVac and BNT162b2 vaccination, respectively. For CoronaVac, the incidence of thrombocytopenia, leukopenia, and neutropenia was 2.51, 1.08, and 0.15 per 10 000 doses. For BNT162b2, the corresponding incidence was 1.39, 1.17, and 0.26 per 10 000 doses. The incidence per 10 000 COVID-19 cases were 1254, 2341, and 884, respectively. We only observed an increased risk of leukopenia following the second dose of BNT162b2 (aOR 1.58, 95% CI 1.24-2.02; day 0-14, IRR 2.21; 95% CI 1.59-3.08). There was no increased risk of

Background: Falls are one of the major causes of injury globally. However, there is a lack of populationbased studies on falls among adolescents, young and middle-aged adults. We therefore aimed to conduct a large-scale population study on the secular trend in incidence of fall-related hospitalization.Methods: A population-wide electronic database, Hong Kong's Clinical Data Analysis and Reporting System (CDARS), was used in this retrospective cohort study. Patients aged ≥10, hospitalized with diagnosis of accidental falls (ICD-9-CM E880-E888) from 2005-2018, were included. Outcome measures included the number, age-and sex-standardized incidence rate of fall-related hospital admissions, their length of stay (LOS) and 1-year all-cause mortality. Linear regression and average annual percentage change (AAPC) using joinpoint regression were computed for trend analysis. Findings: From 2005 to 2018, a total of 336,439 patients aged ≥10 were identified with fall-related hospitalization. Among these fall patients, 33.7% occurred at age < 60. The number of fall-related hospital admissions episodes increased significantly by 83.7% during the study period. The standardized incidence rate of falls per 10 0 0 person-years increased from 3.67 (95% CI 3.62-3.72) in 2005 to 4.79 (95% CI 4.74-4.84) in 2018. Although the total hospitalized bed-days increased from 178,723 days in 2005, to 299,273 days in 2018 ( + 67.5%,p < .0 0 01), the median length of stay per episode of falls decreased from 4.90 days to 3.79 days (p < .0 0 01).Interpretation: Continuous increase in the incidence of fall-related hospitalization in people aged ≥10 was observed. This suggested that falls are a public health issue in all ages. Further studies on the differences in the underlying risk factors and comorbidities between younger and older fall patients are warranted.