Background: Solid-organ transplant recipients (SOTR) have a higher risk of COVID-19 complications and death, and a less powerful and lasting response to vaccines and to natural infection. In Colombia, this population was prioritized in the National Vaccination Plan against COVID-19 and received vaccines from different platforms. The aim of this study was to estimate the effectiveness of the complete vaccination schedule and of the vaccine booster for COVID-19 administered to SOTR in Colombia. Methods: A nested-cohort was assembled within the population-based ESPERANZA cohort and included the subset of 16 and older SOTR (n= 6963); the follow-up period spanned from March 11, 2021 to May 11, 2022. The vaccine effectiveness was estimated with Cox proportional-hazards models, so that the overall effectiveness of the complete vaccination schedule, the vaccine booster, each used vaccine and the homologous and heterologous schedules were estimated, adjusting by the main confounders. Results: The overall effectiveness of being fully vaccinated was 73.7% (IC95% 68.9%-77.0%) to prevent COVID-19 infection; 83.7% (IC95% 78.7%-87.5%) to prevent hospitalization; and 92.1% (IC95%: 88.8%-94.4%) to prevent death due to COVID-19. Similarly, the effectiveness of the vaccine booster was 76.7% (IC95% 70.6%-81.5%); 86.9% (IC95% 79.4%-91.6%); and 94.5% (IC95% 89.8%-97.1%) to prevent confirmed COVID-19 infection, hospitalization and death due to COVID-19, respectively. In both cases, there were no statistically significant differences across age groups. Conclusions: Findings from this work show a high protection of vaccination against infection, hospitalization and death due to COVID-19 in SOTR, which increases with the vaccine booster.