Results
VIRUS
In this work, we determined NAbs titers in a cohort of SOTRs inoculated with the two-dose regimen of the mRNA vaccine BNT162b2 or the inactivated virus vaccine CoronaVac and receiving two boosters of BNT162b2 five months apart (Study flow-chart and protocol of the observational clinical cohort study.The vaccination process in SOTRs began at a median of 24.7 months (IQR 7.6 - 48) after the transplant. All the patients were on immunosuppression (described in In a previous report, we showed that neutralization levels of antibodies elicited by CoronaVac and BNT162b2 against the SARS-CoV-2 Wuhan-Hu-1 Spike are not affected by the D614G mutation that originated the B.1 lineage (First, we compared NAb titers induced by the two-dose scheme of BNT162b2 or CoronaVac in SOTRs and healthy volunteers against the D614G pseudovirus at 90 days after the second dose (Neutralization titers of serum from Healthy and SOTRs 90 days after the two-dose BNT162b2 and CoronaVac vaccines. 50% pseudovirus neutralization titers (pVNTImportantly, we assessed the seropositivity of the samples by a lateral flow rapid test kit to detect IgG anti-SARS-CoV-2 Spike antibodies (We then looked at the neutralizing ability of antibodies against the SARS-CoV-2 variant of concern Omicron (Neutralization titers of serum from SOTRs across the homologous and heterologous boosters. We then analyzed the impact of one and two BNT162b2 booster doses inoculated with a 5-month interval in those SOT recipients who do not drop out of the study (CoronaVac (n=21; 1Finally, we evaluated whether NAbs induced by one or two booster doses were able to neutralize the Omicron variant. Interestingly, NAbs elicited by a heterologous booster in SOTRs neutralize the Omicron variant in a 5.9-fold increase (