Longitudinal Study after Sputnik V Vaccination Shows Durable SARS-CoV-2 Neutralizing Antibodies and Reduced Viral Variant Escape to Neutralization over Time.

Recent studies have shown a temporal increase in the neutralizing antibody potency and breadth to SARS-CoV-2 variants in coronavirus disease 2019 (COVID-19) convalescent individuals. Here, we examined longitudinal antibody responses and viral neutralizing capacity to the B.1 lineage virus (Wuhan related), to variants of concern (VOC; Alpha, Beta, Gamma, and Delta), and to a local variant of interest (VOI; Lambda) in volunteers receiving the Sputnik V vaccine in Argentina. Longitudinal serum samples (N = 536) collected from 118 volunteers obtained between January and October 2021 were used. The analysis indicates that while anti-spike IgG levels significantly wane over time, the neutralizing capacity for the Wuhan-related lineages of SARS-CoV-2 and VOC is maintained within 6 months of vaccination. In addition, an improved antibody cross-neutralizing ability for circulating variants of concern (Beta and Gamma) was observed over time postvaccination. The viral variants that displayed higher escape to neutralizing antibodies with respect to the original virus (Beta and Gamma variants) were the ones showing the largest increase in susceptibility to neutralization over time after vaccination. Our observations indicate that serum neutralizing antibodies are maintained for at least 6 months and show a reduction of VOC escape to neutralizing antibodies over time after vaccination. IMPORTANCE Vaccines have been produced in record time for SARS-CoV-2, offering the possibility of halting the global pandemic. However, inequalities in vaccine accessibility in different regions of the world create a need to increase international cooperation. Sputnik V is a recombinant adenovirus-based vaccine that has been widely used in Argentina and other developing countries, but limited information is available about its elicited immune responses. Here, we examined longitudinal antibody levels and viral neutralizing capacity elicited by Sputnik V vaccination. Using a cohort of 118 volunteers, we found that while anti-spike antibodies wane over time, the neutralizing capacity to viral variants of concern and local variants of interest is maintained within 4 months of vaccination. In addition, we observed an increased cross-neutralization activity over time for the Beta and Gamma variants. This study provides valuable information about the immune response generated by a vaccine platform used in many parts of the world.

Sputnik V vaccine elicits seroconversion and neutralizing capacity to SARS-CoV-2 after a single dose.

Massive vaccination offers great promise for halting the global COVID-19 pandemic. However, the limited supply and uneven vaccine distribution create an urgent need to optimize vaccination strategies. We evaluate SARS-CoV-2-specific antibody responses after Sputnik V vaccination of healthcare workers in Argentina, measuring IgG anti-spike titers and neutralizing capacity after one and two doses in a cohort of naive or previously infected volunteers. By 21 days after receiving the first dose of the vaccine, 94% of naive participants develop spike-specific IgG antibodies. A single Sputnik V dose elicits higher antibody levels and virus-neutralizing capacity in previously infected individuals than in naive ones receiving the full two-dose schedule. The high seroconversion rate after a single dose in naive participants suggests a benefit of delaying administration of the second dose to increase the number of people vaccinated. The data presented provide information for guiding public health decisions in light of the current global health emergency.

FUSARIUM SOLANI SUBRETINAL ABSCESS IN A PATIENT WITH ACUTE MYELOID LEUKEMIA.

PURPOSE: To report on a case of Fusarium solani subretinal abscess in a patient with acute myeloid leukemia treated with an allogenic bone marrow transplant. METHODS: A 47-year-old male with a history of acute myeloid leukemia with intermediate cytogenetic risk was admitted in our hospital. The disease relapsed after two cycles of chemotherapy. He was then treated with an allogenic bone marrow transplant, with busulfan, cyclophosphamide, and thymoglobulin. One week after the procedure, a sepsis of unknown origin in neutropenia occurred. Blood cultures and sputum were negative for bacteria and fungi. At the eighth week after the procedure, the patient had acute vision loss of the right eye. Funduscopy in the right eye revealed an inferior temporal yellowish white elevated lesion of approximately 10 disk areas and superficial perifoveal and perilesional hemorrhages. RESULTS: Vitrectomy was performed and samples from the vitreous and the subretinal abscess material were sent for analysis. Vitreous and subretinal specimens grew colonies of a fungus morphologically consistent with F. solani. CONCLUSION: Fusarium solani should be included in the differential diagnosis of subretinal abscesses.

Evaluación de la técnica de reacción en cadena de la polimerasa para la detección temprana de la transmisión congénita de la enfermedad de Chagas / Evaluation of the polymerase chain reaction technique for the early detection of congenital Chagas’ disease

INTRODUCCION: La detección precoz de Chagas congénito es sumamente importante, ya que el tratamiento inmediato aumenta la eficacia y disminuye las complicaciones en el neonato.OBJETIVO: Evaluar si la utilización de la reacción en cadena de la polimerasa (RCP) aumenta significativamente la sensibilidad y la precocidad diagnóstica con respecto al micrométodo para Chagas.METODOS: El diseño del ensayo fue prospectivo, observacional y longitudinal. Se estudió a 43 recién nacidos, hijos de madres con enfermedad de Chagas atendidas en tres hospitales de la provincia de Buenos Aires (Hospital Evita de Lanús, Hospital de Lomas de Zamora y Hospital de Ezeiza) desde enero de 2010 hasta abril de 2011. Antes del alta, se tomó una muestra de sangre a los neonatos con guanidina-EDTA para realizar la RCP y otra con heparina para realizar micrométodo, con un segundo y un tercer control dentro del mes de vida y serología al octavo mes.RESULTADOS: De las 43 muestras extraídas, 2 fueron eliminadas del estudio por dar negativa la RCP para B-actina. De las 41 muestras evaluadas, se obtuvieron los siguientes resultados: 1 con micrométodo y RCP positiva y 40 con micrométodo y RCP negativas. Se realizó serología a los 25 pacientes que llegaron al octavo mes de control, con micrométodo y RCP negativas, que resultaron no reactivas.CONCLUSIONES: Según el estudio, la RCP y el micrométodo tuvieron una sensibilidad y especificidad comparables. Por lo tanto, la RCP es un método alternativo para el control de la transmisión connatal.

INTRODUCTION: The early detection of congenital Chagas is extremely important, because the immediate treatment increases the efficiency and reduces complications in the newborn.OBJECTIVE: To assess whether the implementation of polymerase chain reaction (PCR) significantly improves the sensitivity and precocious diagnosis comparing to the micromethod for Chagas.METHODS: A prospective, observational and longitudinal test was performed. It analyzed 43 newborns from chagasic mothers assissted in 3 hospitals of Buenos Aires province (Lanús, Lomas de Zamora and Ezeiza) from January 2010 until April 2011. Before the discharge a newborn blood sample was taken and preserved in guanidine-EDTA for PCR, while another one was stored in heparin for micromethod, with a second and third control within the first month of life and serodiagnosis at the eighth month.RESULTS: Of the 43 blood samples collected, 2 were eliminated from the study because of the absence of band at PCR with b-actin. The 41 blood samples finally evaluated yielded following results: 1 with positive micromethod and PCR, and 40 with negative micromethod and PCR. Serodiagnosis was carried out to the 25 patients that reached the eighth month control, with negative micromethod and PCR, resultin non-reactive.CONCLUSIONS: According to this study, PCR and micromethod have a comparable sensitivity and specificity. Therefore, PCR is an alternative method to control the transmission of congenital Chagas.

Evaluación de la técnica de reacción en cadena de la polimerasa para la detección temprana de la transmisión congénita de la enfermedad de Chagas / Evaluation of the polymerase chain reaction technique for the early detection of congenital Chagas disease

INTRODUCCION: La detección precoz de Chagas congénito es sumamente importante, ya que el tratamiento inmediato aumenta la eficacia y disminuye las complicaciones en el neonato.OBJETIVO: Evaluar si la utilización de la reacción en cadena de la polimerasa (RCP) aumenta significativamente la sensibilidad y la precocidad diagnóstica con respecto al micrométodo para Chagas.METODOS: El diseño del ensayo fue prospectivo, observacional y longitudinal. Se estudió a 43 recién nacidos, hijos de madres con enfermedad de Chagas atendidas en tres hospitales de la provincia de Buenos Aires (Hospital Evita de Lanús, Hospital de Lomas de Zamora y Hospital de Ezeiza) desde enero de 2010 hasta abril de 2011. Antes del alta, se tomó una muestra de sangre a los neonatos con guanidina-EDTA para realizar la RCP y otra con heparina para realizar micrométodo, con un segundo y un tercer control dentro del mes de vida y serología al octavo mes.RESULTADOS: De las 43 muestras extraídas, 2 fueron eliminadas del estudio por dar negativa la RCP para B-actina. De las 41 muestras evaluadas, se obtuvieron los siguientes resultados: 1 con micrométodo y RCP positiva y 40 con micrométodo y RCP negativas. Se realizó serología a los 25 pacientes que llegaron al octavo mes de control, con micrométodo y RCP negativas, que resultaron no reactivas.CONCLUSIONES: Según el estudio, la RCP y el micrométodo tuvieron una sensibilidad y especificidad comparables. Por lo tanto, la RCP es un método alternativo para el control de la transmisión connatal.

INTRODUCTION: The early detection of congenital Chagas is extremely important, because the immediate treatment increases the efficiency and reduces complications in the newborn.OBJECTIVE: To assess whether the implementation of polymerase chain reaction (PCR) significantly improves the sensitivity and precocious diagnosis comparing to the micromethod for Chagas.METHODS: A prospective, observational and longitudinal test was performed. It analyzed 43 newborns from chagasic mothers assissted in 3 hospitals of Buenos Aires province (Lanús, Lomas de Zamora and Ezeiza) from January 2010 until April 2011. Before the discharge a newborn blood sample was taken and preserved in guanidine-EDTA for PCR, while another one was stored in heparin for micromethod, with a second and third control within the first month of life and serodiagnosis at the eighth month.RESULTS: Of the 43 blood samples collected, 2 were eliminated from the study because of the absence of band at PCR with b-actin. The 41 blood samples finally evaluated yielded following results: 1 with positive micromethod and PCR, and 40 with negative micromethod and PCR. Serodiagnosis was carried out to the 25 patients that reached the eighth month control, with negative micromethod and PCR, resultin non-reactive.CONCLUSIONS: According to this study, PCR and micromethod have a comparable sensitivity and specificity. Therefore, PCR is an alternative method to control the transmission of congenital Chagas.