Acute effects of COVID-19 vaccination on inflammatory, macrovasular and microvascular biomarkers

ABSTRACT

Purpose: 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. Methods: 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. 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), microvascular function that was estimated with hyperemic mean blood flow velocity (HMBFV) of the brachial artery, and inflammation measured by high-sensitivity C-reactive protein (hsCRP) and interleukins (hsIL-6 and hsIL-1b) in blood samples. The outcomes were assessed prior to, and at 8h, 24h post the 1st dose of vaccination, and 8h, 24h and 48h post the 2nd. Results: There was an increase in hsCRP that was apparent at 24h 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 48h −6.60 [95% CI −9.80 to −3.40], p<0.001) compared to sham. Similarly, interleukins also increased. The vaccine did not change PWV. FMD remained unchanged during the 1st dose but decreased significantly by 1.5% (95% CI 0.1% to 2.9%, p=0.037) at 24h post the 2nd dose (Figure). FMD values returned towards baseline at 48h. HMBFV remained unchanged during the 1st dose but at 48h post the 2nd dose was numerically lower than the sham procedure but the difference between the 2 sessions was not statistically significant (max mean difference at 48h 8.6 [95% CI −0.6 to 17.8], p=0.067). 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 24h that returns towards baseline at 48h. These results confirm the short-term cardiovascular safety of the vaccine. Funding Acknowledgement Type of funding sources None.Figure 1