Risk of lymphadenopathy from SARS-CoV-2 vaccination in Korea: a self-controlled case series analysis

Abstract

OBJECTIVES: To assess the risk of lymphadenopathy following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination.METHODS: A self-controlled case series design was used to determine whether the risk of lymphadenopathy was higher in the 1-day to 42-day risk interval after coronavirus disease 2019 (COVID-19) vaccination compared to the control period. In addition, subgroup analyses were conducted according to baseline characteristics, time since vaccination, and sensitivity analyses adjusted for the length of the risk interval.RESULTS: The risk of developing lymphadenopathy in the risk interval (1-42 days) after COVID-19 vaccination compared to the control period was significantly increased, with a relative incidence (RI) of 1.17 (95% confidence interval [CI], 1.17 to 1.18) when the first, second, and third doses were combined. The RI was greater on the day of vaccination (1.47; 95% CI, 1.44 to 1.50). In subgroup analyses by baseline characteristics, a significantly increased risk or trend toward increased risk was observed in most subgroups except for those aged 70 years and older, with a significant increase in risk in younger individuals, those with a Charlson’s comorbidity index <5, and those who received mRNA vaccines (mRNA-1273>BNT162b2). Within the 1-day to 42-day post-dose risk period, the relative risk was highest during the 1-day to 7-day post-dose period (1.59; 95% CI, 1.57 to 1.60) compared to the control period, and then the risk declined. In the sensitivity analysis, we found that the longer the risk window, the smaller the RI.CONCLUSIONS: SARS-CoV-2 vaccination is associated with a statistically significant increase in the risk of lymphadenopathy, and this risk was observed only with mRNA vaccines.

Seroprevalence of leptospirosis in a Mexican military population working with animals

“…It can be seen that the highest percentage of seroprevalence is found in the 30-44 age range, with 48.1%, which can be explained because it is the age group where the majority of personnel are in service, but greater than that reported in other military populations, where the risk factor turned out to be in the 18-30-year age range in the EE.UU. and Guam [7,10], or even in those that had less than 6 years in active service in the military personnel of Korea [9].…”

“…Currently, the military population is viewed as highly vulnerable to this illness due to the execution of operations and activities that bring them in direct contact with reservoirs or, in fact, expose them to diverse conditions that increase the risk of infection, such as the deployment of troops in the case of severe flooding. There has been reported seroprevalence in American, Korean, and Malaysian military populations of 11.6%, 10.1%, and 16.2%, respectively [7][8][9].…”