Seroconversión rates following covid-19 Pfizer vaccine application among health personnel

Seroconversión posterior a la aplicación de vacuna Pfizer anticovid-19 en personal de la salud

Introduction: the COVID-19 pandemic prompted unprecedented efforts to manufacture vaccines in record time. Given the emergency, to conduct the established pharmacovigilance protocols was not possible, thus, the importance of carrying out local studies which contribute to gain understanding and clinical and pharmacological surveillance. Objectives: to evaluate antibody levels developed in subjects who received the Pfizer vaccine; to determine the most frequent side effects; and describe all-cause 1-year mortality in this group. Methods: a prospective, cross-sectional study in a cohort of 105 patients. Descriptive statistics were conducted by univariate and bivariate analyses of antibody levels. The correlation between age and antibody levels and the crude 1-year mortality rate among patients is described. Results: mean age was 36.45 years (SD 10.11), with a tendency for antibody levels to increase with the second dose and decrease with the third dose. A significant negative correlation was found between age and antibody levels in the second dose. Conclusions: younger subjects had higher antibody titers, which decreased over time. The variability of titer estimates may depend on several factors such as, age, gender, immunosuppressive therapies and comorbidities. Measurements are essential for periodic and individualized vaccination. One-year mortality rate was 0%.

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