COVID-19 vaccination and long COVID among 50 years older and above European: The role of chronic multimorbidity.

ABSTRACT

BACKGROUND AND AIMS: We aimed to explore the association between coronavirus disease-19 (COVID-19) vaccination and long COVID according to the status of chronic multimobidity. METHODS: A total of 1913 participants were recruited in the cross-sectional study on the basis of the Survey of Health and Retirement in Europe. COVID-19 vaccination was defined as vaccination within the last 12 months. Chronic multimorbidity was defined as history of 2 + chronic disease. The study outcome was long COVID during the 12-month follow-up. Multivariable logistic models were performed to estimate the influence of chronic multimorbidity on the association of vaccination with long COVID. Net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were calculated. RESULTS: Chronic multimorbidity significantly modified the association of COVID-19 vaccination with long COVID (Pinteraction = 0.024). The rates of study outcome were significantly lower among vaccinated participants in the chronic multimorbidity subgroup, but not in the other subgroup. Multivariable odds ratios (95 % confidence intervals) of study outcome for unvaccination vs. vaccination were 1.494 (1.013-2.203) in those with multimorbidity and 0.915 (0.654-1.280) in those without multimorbidity, respectively. Adding COVID-19 vaccination to a model containing conventional risk factors significantly improved risk reclassification for study outcome among those with chronic multimobidity (continuous NRI was 25.39 % [P = 0.002] and IDI was 0.42 % [P = 0.075]) CONCLUSION: An inverse association of COVID-19 vaccination with long COVID was found among participants with chronic multimorbidity, but not among those without chronic multimorbidity. Chronic multimorbidity might expand the influence of unvaccination on developing long COVID among European aged ≥50 years.