Low Performance of Sinovac Vaccine Particularly With Belatacept Therapy in a Study With Different Types of COVID-19 Vaccines in Transplanted Patients.

The huge impact of SARS-CoV-2 infections on organ transplant recipients makes it necessary to optimize vaccine efficacy in this population. To effectively implement multiple strategies, it is crucial to understand the performance of each type of available vaccine. In our study, the antibody titer was measured, and the presence of antibodies against SARS-CoV-2 was evaluated after 90 days of immunization; furthermore, the differences between hybrid immunity, immunity by vaccination, and immunosuppressant type were identified.

Seroprevalence of anti-SARS-CoV-2 antibodies in Colombia, 2020: A population-based study.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to cause very high morbidity and mortality throughout Latin American countries. However, few population-based seroprevalence surveys have been conducted to quantify attack rates and characterize drivers of transmission.

Methods: We conducted a population-based cross-sectional study to assess the seroprevalence of antibodies against SARS-CoV-2 in ten cities in Colombia between September and December 2020.