Correlation between COVID-19 vaccination and inflammatory musculoskeletal disorders (preprint)

ImportanceEarlier research on COVID-19 vaccines identified a range of adverse reactions related to proinflammatory actions that can lead to an excessive immune response and sustained inflammation. However, no study has been conducted on the association between inflammatory musculoskeletal disorders and COVID-19 vaccines. ObjectiveTo investigate the incidence rates of inflammatory musculoskeletal disorders following COVID-19 vaccination and to compare them with those of unvaccinated individuals. Design, Setting, and ParticipantsThis retrospective nationwide cohort study used data from the Korean National Health Insurance Service (NHIS) database, involving 2,218,715 individuals. Data were collected from January 1, 2021, to 12 weeks after the second dose of vaccine for vaccinated individuals and 12 weeks after September 30, 2021, for unvaccinated individuals. ExposuresStatus was categorized as unvaccinated and vaccinated with mRNA vaccine, viral vector vaccine, and mixing and matching. Main Outcomes and MeasuresThe primary outcome was the occurrence of inflammatory musculoskeletal disorders that were selected as plantar fasciitis (ICD code, M72.2), rotator cuff syndrome (M75.1), adhesive capsulitis (M75.0), herniated intervertebral disc (HIVD) (M50.2/M51.2), spondylosis (M47.9), bursitis (M71.9), Achilles tendinitis (M76.6), and de-Quervain tenosynovitis (M65.4). Multivariate logistic regression analysis was used to determine the risk factors of musculoskeletal disorders after adjusting for potential confounders. ResultsAmong the 2,218,715 individuals, 1,882,640 (84.9%) received two doses of the COVID-19 vaccine, and 336,075 (15.1%) did not. At 12 weeks after vaccination, the incidences of plantar fasciitis (0.14-0.17%), rotator cuff syndrome (0.29-0.42%), adhesive capsulitis (0.29-0.47%), HIVD (0.18-0.23%), spondylosis (0.14-0.23%), bursitis (0.02-0.03%), Achilles tendinitis (0.0-0.05%), and de-Quervain tenosynovitis (0.04-0.05%) were higher in all three vaccinated groups (mRNA, cDNA, and mixing and matching vaccines) when compared to the unvaccinated group. All COVID-19 vaccines were identified as significant risk factors for each inflammatory musculoskeletal disorder (odds ratio, 1.404-3.730), except for mixing and matching vaccines for de-Quervain tenosynovitis. Conclusions and RelevanceThis cohort study found that individuals who received any COVID-19 vaccine were more likely to be diagnosed with inflammatory musculoskeletal disorders than those who did not. This information will be useful in clarifying the adverse reactions to COVID-19 vaccines and informing people about their potential for inflammatory musculoskeletal disorders after vaccination.

The spectrum of non-fatal immune-related adverse events following COVID-19 vaccination: The population-based cohort study in Seoul, South Korea (preprint)

ObjectiveTo examine the incidence rate and risk of non-fatal irAEs, including gynecological, hematological, dermatological, ophthalmological, otologic, and dental problems following the COVID-19 vaccination. MethodsWe conducted a population-based cohort study from the National Health Insurance Service (NHIS) database in Seoul, South Korea. The non-fatal irAEs included gynecological, hematological, dermatological, ophthalmological, ear, and periodontal problems as reported by the Vaccine Adverse Event Reporting Center. The cumulative incidence rate per 10,000 population, Odds ratio, and Hazard ratio (HR) with 95% Confidence Interval (CI) were measured to assess the non-fatal irAEs after COVID-19 vaccination. ResultsThe cIR of non-fatal irAEs for three months was significantly higher in vaccinated subjects than in non-vaccinated subjects, except for endometriosis. The vaccination significantly increased the risks of all the non-fatal irAEs except for visual impairment. The risk of inner ear disease showed the highest HRs (HR [95% CI] = 2.368 [2.153-2.604]) among the non-fatal irAEs following COVID-19 vaccination. Among the vaccinated subjects, heterologous vaccination was associated with the increased risk of most of the non-fatal irAEs. ConclusionsThe three-month risks of incidental non-fatal irAEs are substantially higher in the COVID-19 vaccinated subjects than in non-vaccinated controls. Our findings suggested that vaccinated subjects with predisposition are potentially vulnerable to the occurrence of diverse irAEs although the COVID-19 vaccines may not be fatal.

Hematologic abnormalities after COVID-19 vaccination: A large Korean population-based cohort study (preprint)

Adverse hematologic events have been reported after COVID-19 vaccination. The objective of this study was to investigate whether hematologic abnormalities develop after COVID-19 vaccination. Retrospective cohort analyses of data from the Korean National Health Insurance Service (KNHIS) database were conducted from July 2022 to August 2023. We randomly selected data of half of those living in Seoul City as of January 1, 2021 with their diagnostic records up to December 31, 2021. The included participants were vaccinated and nonvaccinated persons aged 20 years or older (n= 4,203,887). Hematologic abnormalities after COVID-19 vaccination were identified as nutritional anemia, hemolytic anemia, aplastic anemia, coagulation defects, and neutropenia using International Classification of Diseases, Tenth Revision codes after index date. Incidence rates of hematologic abnormalities in the vaccination group 3 months after vaccination were significantly higher than those in the nonvaccinated group: 14.79 vs. 9.59 (P<.001) for nutritional anemia, 7.83 vs. 5.00 (P<.001) for aplastic anemia, and 4.85 vs. 1.85 (P<.001) for coagulation defects. COVID-19 mRNA vaccine was associated with higher development of nutritional anemia (odds ratio [OR], 1.230 [95% CI, 1.129-1.339], P<.001) and aplastic anemia (OR, 1.242 [95% CI, 1.110-1.390], P<.001) than the viral vector vaccine. The risk of coagulation defects was increased (OR, 1.986 [95% CI, 1.523-2.589], P<.001) after vaccination, and there was no risk difference between mRNA vaccine and viral vector vaccine (OR, 1.075 [95% CI, 0.936-1.233], P=.306). In conclusions, COVID-19 vaccination increased the risk of hematologic abnormalities. When administering the COVID-19 vaccine, careful observation will be necessary after vaccination.