Comparison of the effectiveness of four SARS-COV-2 v accines in Nuevo Leon, Mexico: A test-negative control study.

OBJECTIVE: The objective of the present study was to provide statewide estimates of real-world effectiveness in reducing the odds of one primary (symptomatic COVID-19 infection) and two secondary outcomes (hospitalization and severe COVID-19 infection) by four vaccines BNT162b2 (Pfizer-BioNTech), ChAdOx1 (AstraZeneca), Ad5-nCoV (CanSinoBIO), and CoronaVac (Sinovac Life Sciences), used in Northeast Mexico. DESIGN: We conducted a test-negative case-control study and analyzed statewide surveillance data from December 2020 to August 2021. SITE: Primary attention and hospitalization. PARTICIPANTS: Two inclusion criteria were applied, age≥18 years and having a real-time reverse-transcriptase-polymerase-chain-reaction assay or a rapid test for antigen detection in postnasal samples (N=164,052). The vaccination was considered complete if at least 14 days had passed since the application of the single or second dose and the beginning of symptomatology. INTERVENTIONS: Does not apply. MAIN MEASUREMENTS: Point and 95% confidence intervals (CI) of vaccine effectiveness were calculated per type of vaccine using the formula 1 - odds ratio, adjusted by sex and age. RESULTS: Complete vaccination offered from none (CoronaVac - Sinovac) to 75% (95%CI 71, 77) (BNT162b2 - Pfizer) effectiveness in reducing symptomatic COVID-19 infection, regardless of sex and age. The fully ChAdOx1 (AstraZeneca) scheme reached the maximum effectiveness in hospitalization (80%, 95%CI 69, 87) and the fully BNT162b2 (Pfizer) scheme the maximum effectiveness in severity (81%, 95%CI 64, 90). CONCLUSIONS: More studies are needed to compare benefits of different vaccines and guide policy makers select the best option for their population.

Severe COVID-19 patients have severe vitamin D deficiency in Northeast Mexico.

Introduction: Objective: the association between vitamin D and COVID-19 severity is not consistent. We compared prevalences and analyzed the association between vitamin D deficiency and COVID-19 severity in Northeast Mexico. Methods: this was a cross-sectional study with individuals consecutively included at a referral diagnostic center during March-September 2020 (n = 181). Concurrently, every patient admitted to intensive care was also consecutively included (n = 116). Serum 25(OH)D < 20 ng/mL was considered vitamin D deficiency. Descriptive, ANOVA, and multivariate ordinal regression analyses were performed. Results: vitamin D deficiency prevalence was 63.8 % (95 % CI, 54.7, 72.0) in severe COVID-19; 25.6 % (95 % CI, 17.4, 36.0) in mild COVID-19; and 42.4 % (95 % CI, 33.2, 52.3) in non-diseased individuals. Vitamin D deficiency increased 5 times the odds of severe COVID-19 (95 % CI, 1.1, 24.3), independently of sex, age, body mass index, and inflammatory markers. Conclusions: this study is the first report of vitamin D deficiency in Northeast Mexico. Vitamin D deficiency was associated with COVID-19 severity.

Introducción: Objetivo: la asociación entre la vitamina D y la gravedad de la COVID-19 no es consistente. Se comparó la prevalencia y se analizó la asociación de la deficiencia de vitamina D con la gravedad de los pacientes con COVID-19 en el noreste de México. Métodos: este fue un estudio transversal. Se incluyó consecutivamente a individuos de un centro de diagnóstico de referencia durante marzo-septiembre de 2020 (n = 181). Paralelamente, se reclutó a todos los pacientes que ingresaron a cuidados intensivos en ese mismo periodo (n = 116). Se consideró que había deficiencia de vitamina D ante cifras de 25(OH)D sérica < 20 ng/ml. Se realizaron un análisis descriptivo, un ANOVA y una regresión ordinal multivariante. Resultados: la prevalencia de la deficiencia de vitamina D fue del 63,8 % (IC del 95 %: 54,7; 72,0) en la COVID-19 grave, del 25,6 % (IC del 95 %: 17,4; 36,0) en la COVID-19 leve y del 42,4 % (IC del 95 %: 33,2; 52,3) sin COVID-19. La deficiencia aumentó 5 veces las probabilidades de una COVID-19 grave (IC del 95 %: 1,1; 23,9) independientemente del sexo, la edad, el índice de masa corporal y los marcadores inflamatorios. Conclusiones: este estudio es el primer informe de la deficiencia de vitamina D en el noreste de México. La deficiencia de vitamina D se asoció con la gravedad de la COVID-19.

Prevalence of IgG antibodies induced by the SARS-COV-2 virus in asymptomatic adults in Nuevo Leon, Mexico.

Population-based immunoglobulin G (IgG) seroprevalence studies in asymptomatic individuals in Latin America are scarce. The objective of the study was to estimate the prevalence and geographic distribution of IgG antibodies induced by natural SARS-CoV-2 infection in asymptomatic adults, 5-8 months after the first case was reported in a northeastern state of Mexico. This was a population-based cross-sectional study carried out in Nuevo Leon during August-November 2020. Individuals ≥18 years with no previous diagnosis or symptoms suggestive of COVID-19 were consecutively screened in one of the busiest subway stations. Also, a search for eligible individuals was done from house-to-house, after selecting densely populated geographic sectors of each of the municipalities of the metropolitan area (n = 4495). The IgG antibodies to SARS-CoV-2 nucleocapsid protein were analyzed. The IgG antibody positivity rate was 27.1% (95% confidence interval [CI]: 25.8, 28.4); there were no differences by sex or age (p > 0.05). Analysis by month showed a gradual increase from 11.9% (August) to 31.9% (November); Week 39 had the highest positivity rate (42.2%, 95% CI: 34.2, 50.7). Most people did not have evidence of previous SARS-CoV-2 infection. Preventive measures and promotion of the COVID-19 vaccine should be strengthened.