Antibody- and T Cell-Dependent Responses Elicited by a SARS-CoV-2 Adenoviral-Based Vaccine in a Socially Vulnerable Cohort of Elderly Individuals.

BACKGROUND: In spite of compelling evidence demonstrating safety and immunogenicity of adenoviral-based SARS-CoV-2 vaccines in the general population, its effects in socially vulnerable elderly individuals are poorly understood. Here we aimed to investigate the efficacy of two doses of combined vector vaccine, the Gam-COVID-Vac (Sputnik-V vaccine), at 14, 42, and 180 days after immunization, in a nursing home for underprivileged population and homeless individuals. METHODS: A phase 3, open-label clinical trial involving administration of two adenoviral vectors (Ad26-Ad5) vaccine, in elderly individuals over the ages of 60 years was performed. SARS-CoV-2 Spike RBD-specific IgG antibodies at days 21-, 42- and 180 post-vaccination was analyzed in sera of individuals receiving two doses of the Sputnik-V vaccine with an interval of 21 days. SARS-CoV-2-specific CD8+ T cell responses, measured by intracellular tumor necrosis factor (TNF) was determined by flow cytometry following antigen-specific cultures. RESULTS: A total of 72 elderly adults with a mean age of 72.6 ± 9.5 years-old was selected after applying the inclusion criteria, all corresponding to an underprivileged population. Two-doses vaccination with Sputnik-V vaccine elicited an antibody-mediated immune response (revealed by quantitative detection of SARS-CoV-2-specific IgG antibodies, CMIA) 70% at day 21, 90% at day 42, and 66.1% at day 180. Fully vaccinated individuals had robust SARS-CoV-2-specific T cell responses, evidenced by TNF production in CD4+ and CD8+ T cells in all time periods analyzed. CONCLUSION: Six months after receipt of the second dose of the Gam-COVID-Vac vaccine, SARS-CoV-2-specific IgG levels declined substantially among the tested population, whereas CD4+ and CD8+ T-cell-mediated immunity remained at high levels. These data suggest that two doses of combined adenoviral-based vaccine elicits a considerable level of SARS-CoV-2 immune responses in elderly individuals, highlighting its safety and immunogenicity in this highly vulnerable population.

Prevalence, risk factors and molecular characterization of Chlamydia trachomatis in pregnant women from Córdoba, Argentina: A prospective study.

BACKGROUND: Chlamydia trachomatis causes the most prevalent bacterial Sexual Transmitted Infection. In pregnant women, untreated chlamydial infections are associated with abortions, premature rupture of membranes, postpartum endometritis, low birth weight and transmission to the newborn. In Córdoba, Argentina, there is little knowledge about the prevalence of Chlamydia trachomatis in women in their third trimester of pregnancy, so, the aim of this study was to evaluate Chlamydia trachomatis prevalence and genotypes present in Cordovan pregnant women with different age and socioeconomic status. METHODS AND FINDINGS: Design: prospective study. Settings: Women population from Cordoba city, Argentina. Population: Pregnant women having 35 to 37 weeks of gestation. Methods: Five hundred and nine cervical swabs were collected. Each sample was subjected to DNA extraction and PCR for Chlamydia trachomatis using primers NRO/NLO and CTP1/CTP2. Positives samples were sequenced to determine genotype. Main outcome measures: Demographic data of the patients were collected to detect a population at risk for this infection. RESULTS: A prevalence of 6.9% (35/509) for Chlamydia trachomatis infection was detected, with 32/295 and 3/214 from pregnant women with low or better economic resources respectively (p = 0,0001). Results showed a significantly increased rate of 11.6% (30/258) in women under 25 years compared with 2% (5/251) in patients over that age (p = 0,00003). Genotype E was the most prevalent. CONCLUSIONS: With these results, we can say that pregnant women under 25 years old and low economic resources are one of the populations in which the screening programs of Chlamydia trachomatis should focus.

Prevalencia de chlamydia trachomatis en embarazadas asistidas en Centros de Salud Municipales de la ciudad de Córdoba

Chlamydia trachomatis (C.trachomatis) produce una de las infecciones de transmisión sexual (ITS) más frecuentes en el mundo. Esta bacteria se asocia a abortos, endometritis posterior al parto y ruptura prematura de membranas. Cuando la infección se transmite al recién nacido puede ocasionar bronquitis, neumonía, conjuntivitis y bajo peso. Objetivo: Determinar la prevalencia de la infección por C. trachomatis en mujeres que cursan el tercer trimestre de embarazo evaluando los factores de riesgo asociados, caracterizando a nivel molecular los genotipos presentes y analizando el costo/beneficio de la implementación del tamizaje de esta infección bacteriana

SUMMARY: Chlamydia trachomatis (C. trachomatis) causes one of the most common sexually transmitted infections (STIs) in the world. This bacterium is associated with abortions, endometritis postpartum, and premature rupture of membranes. When the infection is transmitted to newborns, it may cause bronchitis, pneumonia, conjunctivitis and low weight. Objective: Determinate the prevalence of C. trachomatis infection in women on their third trimester of pregnancy, evaluating associated risk factors, characterizing the genotypes at the molecular level, analyzing the cost / benefit rate of implementing the screening of the bacterial infection