Omicron Waves in Argentina: Dynamics of SARS-CoV-2 Lineages BA.1, BA.2 and the Emerging BA.2.12.1 and BA.4/BA.5.

The COVID-19 pandemic has lately been driven by Omicron. This work aimed to study the dynamics of SARS-CoV-2 Omicron lineages during the third and fourth waves of COVID-19 in Argentina. Molecular surveillance was performed on 3431 samples from Argentina, between EW44/2021 and EW31/2022. Sequencing, phylogenetic and phylodynamic analyses were performed. A differential dynamic between the Omicron waves was found. The third wave was associated with lineage BA.1, characterized by a high number of cases, very fast displacement of Delta, doubling times of 3.3 days and a low level of lineage diversity and clustering. In contrast, the fourth wave was longer but associated with a lower number of cases, initially caused by BA.2, and later by BA.4/BA.5, with doubling times of about 10 days. Several BA.2 and BA.4/BA.5 sublineages and introductions were detected, although very few clusters with a constrained geographical distribution were observed, suggesting limited transmission chains. The differential dynamic could be due to waning immunity and an increase in population gatherings in the BA.1 wave, and a boosted population (for vaccination or recent prior immunity for BA.1 infection) in the wave caused by BA2/BA.4/BA.5, which may have limited the establishment of the new lineages.

Immunogenicity and reactogenicity of heterologous immunization against SARS CoV-2 using Sputnik V, ChAdOx1-S, BBIBP-CorV, Ad5-nCoV, and mRNA-1273.

Heterologous vaccination against coronavirus disease 2019 (COVID-19) provides a rational strategy to rapidly increase vaccination coverage in many regions of the world. Although data regarding messenger RNA (mRNA) and ChAdOx1 vaccine combinations are available, there is limited information about the combination of these platforms with other vaccines widely used in developing countries, such as BBIBP-CorV and Sputnik V. Here, we assess the immunogenicity and reactogenicity of 15 vaccine combinations in 1,314 participants. We evaluate immunoglobulin G (IgG) anti-spike response and virus neutralizing titers and observe that a number of heterologous vaccine combinations are equivalent or superior to homologous schemes. For all cohorts in this study, the highest antibody response is induced by mRNA-1273 as the second dose. No serious adverse events are detected in any of the schedules analyzed. Our observations provide rational support for the use of different vaccine combinations to achieve wide vaccine coverage in the shortest possible time.

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.

Pre-treatment drug resistance and HIV-1 subtypes in infants from Argentina with and without exposure to antiretroviral drugs for prevention of mother-to-child transmission.

OBJECTIVES: To assess the prevalence and patterns of pre-treatment HIV drug resistance (PDR) and HIV-1 subtype in infants from Argentina with exposure to different antiretroviral drugs (ARVs) for the prevention of mother-to-child transmission (PMTCT). PATIENTS AND METHODS: HIV-1 genotyping was performed in 115 infants (median age = 2.3 months) born between 2007 and 2014 to screen for drug resistance mutations (DRMs) before starting first-line ART. HIV-1 subtype was characterized by phylogenetic and recombination analysis. RESULTS: Overall, DRMs were found in 34 of 115 infants (PDR level 30% to any ARV, 3.5% to PIs, 12% to NRTIs and 22% to NNRTIs). Of the 115 infants, 22 (19.1%) were ARV-unexposed. Another 93 were ARV-exposed: 28 (24.3%) to short-course zidovudine monotherapy ARV prophylaxis; 25 (21.7%) to nevirapine-based ARV prophylaxis; 12 (10.4%) to perinatal infant zidovudine prophylaxis + maternal combination ART with NNRTIs; and 28 (24.3%) to perinatal infant zidovudine prophylaxis+maternal combination ART with PIs. Transmitted drug resistance among ARV-unexposed infants was 32% (5% to PIs, 9% to NRTIs and 18% to NNRTIs). ART-exposed infants showed multi-class ARV resistance. Importantly, vertical transmission of a triple-class-resistant virus was confirmed in one case. Patterns of DRMs predicted high-level resistance to NNRTIs in a similar and high proportion (>50%) of infants with at least one DRM independently of ARV exposure. BF recombinants were found in 74%, subtype B in 20%, subtype C in 3% and novel AG and AB recombinants in 3%. CONCLUSIONS: PDR in HIV-1-infected children from Argentina is among the highest reported, jeopardizing successful lifelong suppressive ART as well as the efficacy of current PMTCT regimens.

Vigilancia y prevención de gripe A H1N1: estableicmiento del perfil clínico epidemiológico de la morbi-mortalidad en la provincia de Buenos Aires / Surveillance and prevention of H1N1 influenza: stermination of the clinical and epidemiologic profile of morbi-mortality in Buenos Aires province

INTRODUCCION: El virus de Influenza A es un patógeno viral de gran impacto clínico que causa infecciones respiratorias agudas. En 2009 la OMS declaró una pandemia por la emergencia de un nuevo subtipo H1N1 de origen porcino.OBJETIVOS: Describir las características de la infección por Influenza A H1N1 en la Provincia de Buenos Aires a partir de la pandemia de 2009.METODOS: Se realizó un estudio retrospectivo de los datos ingresados al Sistema de Vigilancia Laboratorial (SIVILA) de la Provincia de Buenos Aires y de muestras de aspirados nasofaríngeos en 3 centros de diagnóstico desde mayo de 2009 hasta abril de 2010. Se utilizó RT-PCR y RT-PCR en tiempo real para el diagnóstico.RESULTADOS: Durante 2009 en la provincia se notificaron 2.316 casos de Influenza A H1N1 al SIVILA. La incidencia más baja se observó en mayores de 65 años, en tanto que la mayor fue en pacientes ambulatorios de entre 5 y 9 años y en pacientes internados menores a 4 años. Entre los pacientes fallecidos se observó mayor incidencia en menores a 4 años y 2 picos en pacientes jóvenes (20-24 y 40-44 años). La tasa de mortalidad fue de 2,36/100.000 habitantes y la de letalidad de 7,85%. En 2010 los 3 centros participantes procesaron 1.000 muestras. Se detectó ARN de virus Influenza A en 25 muestras y una fue diagnosticada por RT-PCR como del subtipo pandémico H1N1.CONCLUSIONES: La mayor incidencia de casos observada en pacientes fallecidos, tanto en jóvenes como en menores de 4 años, coincide con lo descrito en pandemias anteriores. Se detectó solamente un caso de H1N1 al año siguiente de la declaración de la pandemia.

INTRODUCTION: The influenza A virus is highly pathogenic and causes acute respiratory infections. In 2009 the World Health Organization declared a pandemic due to an emergent new variant of the influenza virus, the strain H1N1 from porcine origin.OBJECTIVE: To describe the profile of H1N1 infection in Buenos Aires Province since 2009 pandemic.METHODS: A retrospective study was conducted with data collected from the National Laboratory Survey System (SIVILA) of Buenos Aires Province. Samples of nasopharyngeal aspirates were used, obtained between May 2009 and April 2010 from three diagnostic reference centers. RT-PCR and Real Time RT-PCR were used for diagnostic purposes.RESULTS: During 2009, 2.316 cases of H1N1 influenza were reported to SIVILA. The lowest incidence was observed in patients of 65 years or older. On the other hand, the highest incidence was detected among non-hospitalized children aged 5 to 9 years and hospitalized children under 4 years old. Among dead patients, the highest incidence was observed in children under 4 years old and in young people aged 40-40 and 20-24 years. Mortality rate was 2.36/100.000 and lethality was 7.85%. In 2010, the three diagnostic centers screened 1.000 samples. 25 samples were positive for influenza A virus, and only one sample tested positive for H1N1 virus subtype by RT-PCR analysis.CONCLUSIONS: The highest incidence of cases observed in dead patients, both in young people and in children under 4 years old, was compatible with the data of previous influenza pandemics. Onle one case of H1N1 infection was detected one year after the pandemic declaration.

Vigilancia y prevención de gripe A H1N1: estableicmiento del perfil clínico epidemiológico de la morbi-mortalidad en la provincia de Buenos Aires / Surveillance and prevention of H1N1 influenza: stermination of the clinical and epidemiologic profile of morbi-mortality in Buenos Aires province

INTRODUCCION: El virus de Influenza A es un patógeno viral de gran impacto clínico que causa infecciones respiratorias agudas. En 2009 la OMS declaró una pandemia por la emergencia de un nuevo subtipo H1N1 de origen porcino.OBJETIVOS: Describir las características de la infección por Influenza A H1N1 en la Provincia de Buenos Aires a partir de la pandemia de 2009.METODOS: Se realizó un estudio retrospectivo de los datos ingresados al Sistema de Vigilancia Laboratorial (SIVILA) de la Provincia de Buenos Aires y de muestras de aspirados nasofaríngeos en 3 centros de diagnóstico desde mayo de 2009 hasta abril de 2010. Se utilizó RT-PCR y RT-PCR en tiempo real para el diagnóstico.RESULTADOS: Durante 2009 en la provincia se notificaron 2.316 casos de Influenza A H1N1 al SIVILA. La incidencia más baja se observó en mayores de 65 años, en tanto que la mayor fue en pacientes ambulatorios de entre 5 y 9 años y en pacientes internados menores a 4 años. Entre los pacientes fallecidos se observó mayor incidencia en menores a 4 años y 2 picos en pacientes jóvenes (20-24 y 40-44 años). La tasa de mortalidad fue de 2,36/100.000 habitantes y la de letalidad de 7,85%. En 2010 los 3 centros participantes procesaron 1.000 muestras. Se detectó ARN de virus Influenza A en 25 muestras y una fue diagnosticada por RT-PCR como del subtipo pandémico H1N1.CONCLUSIONES: La mayor incidencia de casos observada en pacientes fallecidos, tanto en jóvenes como en menores de 4 años, coincide con lo descrito en pandemias anteriores. Se detectó solamente un caso de H1N1 al año siguiente de la declaración de la pandemia.

INTRODUCTION: The influenza A virus is highly pathogenic and causes acute respiratory infections. In 2009 the World Health Organization declared a pandemic due to an emergent new variant of the influenza virus, the strain H1N1 from porcine origin.OBJECTIVE: To describe the profile of H1N1 infection in Buenos Aires Province since 2009 pandemic.METHODS: A retrospective study was conducted with data collected from the National Laboratory Survey System (SIVILA) of Buenos Aires Province. Samples of nasopharyngeal aspirates were used, obtained between May 2009 and April 2010 from three diagnostic reference centers. RT-PCR and Real Time RT-PCR were used for diagnostic purposes.RESULTS: During 2009, 2.316 cases of H1N1 influenza were reported to SIVILA. The lowest incidence was observed in patients of 65 years or older. On the other hand, the highest incidence was detected among non-hospitalized children aged 5 to 9 years and hospitalized children under 4 years old. Among dead patients, the highest incidence was observed in children under 4 years old and in young people aged 40-40 and 20-24 years. Mortality rate was 2.36/100.000 and lethality was 7.85%. In 2010, the three diagnostic centers screened 1.000 samples. 25 samples were positive for influenza A virus, and only one sample tested positive for H1N1 virus subtype by RT-PCR analysis.CONCLUSIONS: The highest incidence of cases observed in dead patients, both in young people and in children under 4 years old, was compatible with the data of previous influenza pandemics. Onle one case of H1N1 infection was detected one year after the pandemic declaration.

Evaluación externa de calidad en hematología: hemoglobina (período 1989-1991) / External quality assessment in hematology: hemoglobin (1989-1991)

Se exponen los resultados obtenidos en el Programa de Evaluación Externa de Calidad (PEEC) en Hematología de la Federación Bioquímica de la provincia de Buenos Aires, durante el período 1989-1991. Este Programa está inserto en el Programa de Evaluación Externa de Calidad en Bioquímica Clínica. El mismo es de carácter voluntario, explícito o anónimo. Inicialmente fueron 911 los inscriptos, y en la actualidad han superado los 1300, incluyendo laboratorios de otras provincias. En esta etapa sólo se ha implementado la evaluación externa para la hemoglobinometría. Se llevaron a cabo ocho encuestas, una de ellas a dos niveles de concentración, observándose que los porcentajes de respuestas aceptados, es decir que caen dentro de Xñ3 DE, oscilan entre 31-95%, con coeficiente de variación (CV) entre 5.8-14.2%. Los porcentajes de laboratorios que se encuentran dentro del límite de aceptabilidad de ñ5% varían entre 22-51%. El envío simultáneo de muestras a dos niveles arrojó diferencias para ambos valores asignados de -10% y -13.5%, lo que indica presencia de un error sistemático. El grado de estandirización logrado está relacionado con el empleo mayoritario de espectrofotómetros de haz simple, del uso de un solo punto de calibración y, como factor más crítico aún, de la existencia de 7-8% de laboratorios que aún no han adoptado el método recomendado de cianmetahemaglobina, todo lo cual justifica ampliamente la continuidad del PEEC

Evaluación externa de calidad en hematología: hemoglobina (período 1989-1991) / External quality assessment in hematology: hemoglobin (1989-1991)

Se exponen los resultados obtenidos en el Programa de Evaluación Externa de Calidad (PEEC) en Hematología de la Federación Bioquímica de la provincia de Buenos Aires, durante el período 1989-1991. Este Programa está inserto en el Programa de Evaluación Externa de Calidad en Bioquímica Clínica. El mismo es de carácter voluntario, explícito o anónimo. Inicialmente fueron 911 los inscriptos, y en la actualidad han superado los 1300, incluyendo laboratorios de otras provincias. En esta etapa sólo se ha implementado la evaluación externa para la hemoglobinometría. Se llevaron a cabo ocho encuestas, una de ellas a dos niveles de concentración, observándose que los porcentajes de respuestas aceptados, es decir que caen dentro de Xñ3 DE, oscilan entre 31-95%, con coeficiente de variación (CV) entre 5.8-14.2%. Los porcentajes de laboratorios que se encuentran dentro del límite de aceptabilidad de ñ5% varían entre 22-51%. El envío simultáneo de muestras a dos niveles arrojó diferencias para ambos valores asignados de -10% y -13.5%, lo que indica presencia de un error sistemático. El grado de estandirización logrado está relacionado con el empleo mayoritario de espectrofotómetros de haz simple, del uso de un solo punto de calibración y, como factor más crítico aún, de la existencia de 7-8% de laboratorios que aún no han adoptado el método recomendado de cianmetahemaglobina, todo lo cual justifica ampliamente la continuidad del PEEC