Thrombotic events following Covid-19 vaccines compared to Influenza vaccines.

IMPORTANCE: The actual risk of thrombotic events after Covid-19 vaccination is unknown. OBJECTIVE: To evaluate the risk of thrombotic events after Covid-19 vaccination. DESIGN: Retrospective cohort study which included consecutive adult patients vaccinated with the first dose of Covid-19 vaccine between January 1 and May 30, 2021, and a historic control group, defined as consecutive patients vaccinated with influenza vaccine between March 1 and July 30, 2019. SETTING: Hospital Italiano de Buenos Aires, a tertiary hospital in Argentina. PARTICIPANTS: Non-Hospitalized Adults vaccinated with the first dose of a Covid-19 vaccine. EXPOSURE: Vaccination with Covid-19 vaccines available during the study period: Gam-COVID-Vac (Sputnik), ChAdOx1 nCoV-19 (AstraZeneca/Oxford or Covishield), BBIBP-CorV (Beijing Institute of Biological Products) (Sinopharm). Active comparator group exposure was Influenza vaccine. MAIN OUTCOME: Primary endpoint was cumulative incidence of any symptomatic thrombotic event at 30 days, defined as the occurrence of at least one of the following: symptomatic acute deep venous thrombosis (DVT); symptomatic acute pulmonary embolism (PE); acute ischemic stroke (AIS); acute coronary syndrome (ACS) or arterial thrombosis. RESULTS: From a total of 29,985 adult patients who received at least a first dose of Covid-19 vaccine during study period and 24,777 who received Influenza vaccine in 2019, we excluded those who were vaccinated during hospitalization. We finally included 29,918 and 24,753 patients respectively. Median age was 73 years old (IQR 75-81) and 67% were females in both groups. Thirty six subjects in the Covid-19 vaccination group (36/29,918) and 15 patients in the Influenza vaccination group (15/24,753) presented at least one thrombotic event. The cumulative incidence of any thrombotic event at 30 days was 12 per 10,000 (95%CI 9-17) for Covid-19 group and 6 per 10,000 (95%CI 4-10) for Influenza group (p-value=0.022). CONCLUSIONS AND RELEVANCE: This study shows a significant increase in thrombotic events in subjects vaccinated with Covid-19 vaccines in comparison to a control group. The clinical implication of these findings should be interpreted with caution, in light of the high effectiveness of vaccination and the inherent risk of thrombosis from Covid-19 infection itself.

Incidence of COVID-19 after pulmonary function tests: a retrospective cohort study.

INTRODUCTION: It has been proposed that exposure to pulmonary function tests (PFT) could be associated with a higher risk of viral transmission. The risk of the Coronavirus Disease 2019 (COVID-19) transmission after performing PFT is unknown. We aimed to assess the incidence  of COVID-19 after a PFT at an academic teaching facility in Buenos Aires, Argentina. MATERIALS AND METHODS: We conducted a retrospective cohort study including all consecutive adult patients that performed PFT between April 1, 2020 and September 30, 2020. Patients with prior COVID-19 were excluded. We defined a 15-day time window to  ascertain PFT related COVID-19. The primary outcome was ascertained by consulting a national database, which has information on all patients with nasopharyngeal swabs for SARS-CoV-2 in Argentina. RESULTS: We included 278 patients who performed a PFT. Fifty percent were women, the mean age was 54 years (SD 18), and the main comorbidities were obesity (31%), smoking (31%), hypertension (29%), and chronic lung disease (28%). The main indication for performing PFT was anesthetic preoperative risk assessment. Swabs were collected from 27 patients (10%). Twenty-two swabs (8%) were taken according to surgical protocols; five swabs (2%) were taken due to clinical suspicion of COVID-19, with only one testing positive. The cumulative incidence of COVID-19 after PFT was 0.36% (95% CI 0.01-20%). None of the technicians developed symptomatic disease. CONCLUSION: Given the right setting and strict adherence to international recommendations, the SARS-CoV-2 infection after having a PFT appears to be low, which follows that these procedures can be performed safely for both patients and staff.

Introducción: Se ha propuesto que las pruebas de función respiratorias (PFR) podrían estar asociadas con un mayor riesgo de transmisión viral. El riesgo de presentar la enfermedad por coronavirus 2019 (COVID-19) después de realizar una PFR es desconocido. El objetivo del estudio fue estimar la incidencia de COVID-19 después de llevar a cabo una PFR, en un Hospital Universitario de la ciudad Autónoma de Buenos Aires, Argentina. Se realizó una cohorte retrospectiva que incluyó a todos los pacientes que realizaron una PFR entre el 1 de abril de 2020 y el 30 de septiembre de 2020. Se excluyeron los pacientes con antecedentes de COVID-19. Definimos una ventana de tiempo de 15 días para determinar la presencia de COVID-19 relacionada con la realización de la PFR. El resultado primario se determinó consultando una base de datos nacional, que contiene información sobre todos los pacientes que se han realizado hisopados nasofaríngeos para detección del SARS-CoV-2 en Argentina. Materiales y métodos: Se incluyeron 278 pacientes, el 50% fueron mujeres, el promedio de edad fue de 54 años (DE 18) y las principales comorbilidades fueron: obesidad (31%), tabaquismo (31%), hipertensión (29%) y enfermedades respiratorias crónicas (28%). La principal indicación de la PFR fue la evaluación pre operatoria o anestésica. A 27 pacientes (10%) se les realizó un hisopado nasofaríngeo para búsqueda de SARS-CoV-2. Veintidós hisopados (8%) se solicitaron por evaluación pre quirúrgica, cinco hisopados (2%) por sospecha clínica de infección y solamente uno fue positivo. La incidencia de COVID-19 fue de 0.36% (IC95% 0.01-20%). Durante el período del estudio ninguno de los operadores que realizaron las PFR presentaron síntomas compatibles con COVID-19. Conclusión: Siguiendo las recomendaciones internacionales, la frecuencia de detección de COVID-19 después de las PFR parece ser bajo, por lo que estos procedimientos se podrían llevar a cabo de forma segura tanto para los pacientes como para el personal.