THE EFFECT OF COVID-19 VACCINE ON ARTERIAL FUNCTION

ABSTRACT

Objective: To fight the COVID-19 pandemic, messenger RNA (mRNA) vaccines were the first to be adopted by vaccination programs worldwide. We sought to investigate the short-term effect of mRNA vaccine administration on endothelial function and arterial stiffness. Design and method: Thirty-two participants (mean age 37 ± 8 years, 20 men) that received the BNT162b2 mRNA COVID-19 vaccine were studied in 3 sessions in a sequence-randomized, sham-controlled, assessor-blinded, cross-over design. The primary outcome was endothelial function assessed by brachial artery flow-mediated dilatation (FMD), and secondary outcomes were aortic stiffness, evaluated with carotid-femoral pulse wave velocity (PWV) and augmentation index (AIx@75), and inflammation measured by high-sensitivity C-reactive protein (hsCRP) in blood samples. The outcomes were assessed prior to, and at 8 h, 24 h post the 1st dose of vaccination, and 8 h, 24 h, and 48 h post the 2nd. Results: There was an increase in hsCRP that was apparent at 24 h after both the 1st dose (-0.60 [95% Confidence intervals [CI] -1.60 to -0.20], p = 0.013) and the 2nd dose (max median difference at 48 h -6.60 [95% CI -9.80 to -3.40], p < 0.001) compared to sham. The vaccine did not change PWV or AIx@75. FMD remained unchanged during the 1st dose but decreased significantly by 1.5% (95% CI 0.1% to 2.9%, p = 0.037) at 24 h post the 2nd dose. FMD values returned towards baseline at 48 h. Conclusions: Our study shows that the mRNA vaccine causes a prominent increase in inflammatory markers, especially after the 2nd dose, and a transient deterioration of endothelial function at 24 h that returns towards baseline at 48 h. These results confirm the short-term cardiovascular safety of the vaccine.