Antibody Avidity Maturation Following Recovery From Infection or the Booster Vaccination Grants Breadth of SARS-CoV-2 Neutralizing Capacity.

BACKGROUND: Cross-neutralizing capacity of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants is important in mitigating (re-)exposures. Role of antibody maturation, the process whereby selection of higher affinity antibodies augments host immunity, to determine SARS-CoV-2 neutralizing capacity was investigated. METHODS: Sera from SARS-CoV-2 convalescents at 2, 6, or 10 months postrecovery, and BNT162b2 vaccine recipients at 3 or 25 weeks postvaccination, were analyzed. Anti-spike IgG avidity was measured in urea-treated ELISAs. Neutralizing capacity was assessed by surrogate neutralization assays. Fold change between variant and wild-type neutralization inferred the breadth of neutralizing capacity. RESULTS: Compared with early-convalescent, avidity indices of late-convalescent sera were significantly higher (median, 37.7 [interquartile range 28.4-45.1] vs 64.9 [57.5-71.5], P < .0001). Urea-resistant, high-avidity IgG best predicted neutralizing capacity (Spearman r = 0.49 vs 0.67 [wild-type]; 0.18-0.52 vs 0.48-0.83 [variants]). Higher-avidity convalescent sera better cross-neutralized SARS-CoV-2 variants (P < .001 [Alpha]; P < .01 [Delta and Omicron]). Vaccinees only experienced meaningful avidity maturation following the booster dose, exhibiting rather limited cross-neutralizing capacity at week 25. CONCLUSIONS: Avidity maturation was progressive beyond acute recovery from infection, or became apparent after the booster vaccine dose, granting broader anti-SARS-CoV-2 neutralizing capacity. Understanding the maturation kinetics of the 2 building blocks of anti-SARS-CoV-2 humoral immunity is crucial.

Safety and immunogenicity of different booster vaccination schemes for COVID-19 used in El Salvador.

Purpose: The effectiveness of coronavirus disease 2019 (COVID-19) vaccination schemes and the combination of vaccines of various platforms for administering booster doses is still being studied since it will depend on the population's response to vaccines. We aimed to evaluate the safety, protection, and immunogenicity of the Salvadorean population's third dose booster COVID-19 vaccine and the potential benefit of homologous vs. heterologous regimens. Materials and Methods: This is an analytical observational cohort study in a population aged 18 to 65 years that was primarily vaccinated with AstraZeneca, Sinovac, or Pfizer/BioNTech. Volunteers were recruited (n=223) and followed up for 3 months after receiving the 3rd vaccine (BNT162b2) as a booster. Adverse reactions were monitored, serum anti-spike immunoglobulin G (IgG) was assessed by chemiluminescence, and a polymerase chain reaction was carried out when subjects developed clinical signs. Results: The cohorts finally included 199 participants, and we observed only mild adverse effects in all cohorts. A significant increase in specific IgG levels was found after the booster dose in all cohorts. The heterologous scheme with Sinovac showed the greatest increase in antibody titer, and a decrease was observed in all participants after 3 months. During the follow-up period, 30 participants showed symptomatology compatible with COVID-19, but only four were laboratory-confirmed and they showed mild clinical signs. Conclusion: These findings indicate that the booster doses used were safe and promoted an immediate increase in immunogenicity, which decreased over time. The heterologous regimen showed stronger immunogenicity compared to the messenger RNA-based homologous scheme.

Estimating averted illnesses from influenza vaccination for children and pregnant women - El Salvador, Panama, and Peru, 2011-2018.

BACKGROUND: Estimating the burden of disease averted by vaccination can assist policymakers to implement, adjust, and communicate the value of vaccination programs. Demonstrating the use of a newly available modeling tool, we estimated the burden of influenza illnesses averted by seasonal influenza vaccination in El Salvador, Panama, and Peru during 2011-2018 among two influenza vaccine target populations: children aged 6-23 months and pregnant women. METHODS: We derived model inputs, including incidence, vaccine coverage, vaccine effectiveness, and multipliers from publicly available country-level influenza surveillance data and cohort studies. We also estimated changes in illnesses averted when countries' vaccine coverage was achieved using four different vaccine deployment strategies. RESULTS: Among children aged 6-23 months, influenza vaccination averted an estimated cumulative 2,161 hospitalizations, 81,907 medically-attended illnesses, and 126,987 overall illnesses during the study period, with a prevented fraction ranging from 0.3 % to 12.5 %. Among pregnant women, influenza vaccination averted an estimated cumulative 173 hospitalizations, 6,122 medically attended illnesses, and 16,412 overall illnesses, with a prevented fraction ranging from 0.2 % to 10.9 %. Compared to an influenza vaccine campaign with equal vaccine distribution during March-June, scenarios in which total cumulative coverage was achieved in March and April consistently resulted in the greatest increase in averted illness (23 %-3,129 % increase among young children and 22 %-3,260 % increase among pregnant women). DISCUSSION: Influenza vaccination campaigns in El Salvador, Panama, and Peru conducted between 2011 and 2018 prevented hundreds to thousands of influenza-associated hospitalizations and illnesses in young children and pregnant women. Existing vaccination programs could prevent additional illnesses, using the same number of vaccines, by achieving the highest possible coverage within the first two months of an influenza vaccine campaign.

Seroprevalence of Anti-SARS-CoV-2 IgG Antibodies in Healthcare Personnel in El Salvador Prior to Vaccination Campaigns.

COVID-19, caused by the SARS-CoV-2 virus, is a highly pathogenic emerging infectious disease. Healthcare personnel (HCP) are presumably at higher risk of acquiring emerging infections because of occupational exposure. The prevalence of COVID-19 in HCP is unknown, particularly in low- to middle-income countries like El Salvador. The goal of this study was to determine the seroprevalence of anti-SARS-CoV-2 antibodies among HCP in El Salvador just prior to vaccine rollout in March 2021. We evaluated 2176 participants from a nationally representative sample of national healthcare institutions. We found 40.4% (n = 880) of the study participants were seropositive for anti-spike protein antibodies. Significant factors associated with infection included younger age; living within the central, more populated zone of the country; living in a larger household (≥7 members); household members with COVID-19 or compatible symptoms; and those who worked in auxiliary services (i.e., housekeeping and food services). These findings provide insight into opportunities to mitigate SARS-CoV-2 risk and other emerging respiratory pathogens in HCP in El Salvador.

Prophylactic treatment abandonment in people bitten by suspected rabid animals, El Salvador, 2013-2017.

Introduction: Around the world 60,000 people die from rabies each year. The main form of exposure to rabies is by the bite of animals infected with the virus. More than 20,000 cases of rabies-transmitting animal bites are reported each year, in El Salvador, a country located in Central America. People exposed should be managed with rabies prophylaxis. Objective: To determine the abandonment of post-exposure prophylaxis (PEP) cumulative incidence (CI) in humans bitten by suspected rabid animals in El Salvador from 2013 to 2017. Methodology: This is an ecological study based on the cases of bites by suspected rabid animals reported between 2013 and 2017 in the public health system of El Salvador. Descriptive and correlation analysis was performed using Statistical Package for the Social Sciences (SPSS) version 24. The municipality CI, expressed per 100,000 inhabitants. Results: The national CI of abandonment PEP in humans bitten by suspected rabid animals was 25.6 × 100,000 inhabitants. Simple bivariate correlation analysis shows that the departments with the highest CI of bites caused by cats, wild animals, and bites on the neck (R 2 = 0.99 P < 0.05) are mostly associated with dropping out of the PEP. Conclusion: In El Salvador, the abandonment CI of PEP is lower than other countries, however, bites by rabid suspected animal are frequent, this represents a public health problem due to the presence of the rabies virus in wild animals and the high lethality of the disease. Municipalities where head bites are common are the most related to the abandonment of PEP.

Incidence of influenza and other respiratory viruses among pregnant women: A multi-country, multiyear cohort.

OBJECTIVE: To quantify rates of influenza illness and assess value of influenza vaccination among pregnant women in Panama and El Salvador. METHODS: Pregnant women were enrolled and followed each week in a prospective cohort study to identify acute respiratory illnesses (ARI). Nasopharyngeal swabs obtained from women with febrile ARI were tested by reverse-transcription polymerase chain reaction for influenza and other respiratory viruses. RESULTS: We enrolled 2556 women between October 2014 and April 2017. Sixteen percent developed at least one ARI; 59 had two ARI, and five had three ARI for a total of 463 ARI. Women in El Salvador and Panama contributed 297 person-years (py) and 293 py, respectively, during influenza circulation. Twenty-one (11%) of 196 sampled women tested positive for influenza. Influenza incidence was 5.0/100 py (5.7/100 py in El Salvador and 4.3/100 py in Panama). Only 13% of women in El Salvador and 43% in Panama had been vaccinated against influenza before influenza epidemics (P < 0.0001). CONCLUSIONS: One in six pregnant women developed ARI and more than one in ten ARI were attributable to vaccine-preventable influenza. While women were at risk of influenza, few had been vaccinated before each epidemic. Such findings suggest the utility of evaluations to optimize vaccine timing and coverage.

Incidence of respiratory virus illness and hospitalizations in a Panama and El Salvador birth cohort, 2014-2018.

Background: Respiratory viruses remain a key cause of early childhood illness, hospitalization, and death globally.The recent pandemic has rekindled interest in the control of respiratory viruses among paediatric populations. We estimate the burden of such viruses among children <2 years. Methods: Enrolled neonates were followed until two years of age. Weekly active symptom monitoring for the development of acute respiratory illnesses (ARI) defined as cough, rhinorrhoea, difficulty breathing, asthenia, anorexia, irritability, or vomiting was conducted. When the child had ARI and fever, nasopharyngeal swabbing was performed, and samples were tested through singleplex RT-PCR. Incidence of respiratory viruses was calculated by dividing the number of laboratory-confirmed detections by the person-time accrued during weeks when that virus was detectable through national surveillance then corrected for under-ascertainment among untested children. Findings: During December 2014-November 2017, 1567 enrolled neonates contributed 2,186.9 person-years (py). Six in ten (64·4%) children developed ARI (total 2493 episodes). Among children <2 years, incidence of respiratory syncytial virus (RSV)-associated ARI episodes (21·0, 95%CI 19·3-22·8, per 100py) and rhinovirus-associated (20·5, 95%CI 20·4-20·7) were similar and higher than parainfluenza 1-3-associated (14·2, 95%CI 12·2-16·1), human metapneumovirus-associated (9·2, 95%CI 7·7-10·8), influenza-associated (5·9, 95%CI 4·4-7·5), and adenovirus-associated ARI episodes (5·1, 95%CI 5·0-5·2). Children aged <3 months had the highest rates of RSV ARI (49·1, 95%CI 44·0-54·1 per 100py) followed by children aged 3-5 (25·1, 95%CI 20·1-30·0), 6-11 (17·6, 95%CI 13·2-21·9), and 12-23 months (11·9, 95%CI 10·8-12·9). One in ten children with RSV was referred to the hospital (2·5, 95%CI 2·1-2·8, per 100py). Interpretation: Children frequently developed viral ARI and a substantive proportion required hospital care. Such findings suggest the importance of exploring the value of new interventions and increasing uptake of existing prevention measures to mitigate burden of epidemic-prone respiratory viruses. Funding: The study was supported by the Centers for Disease Control and Prevention.

Multi-site clinical validation of Isothermal Amplification based SARS-COV-2 detection assays using different sampling strategies.

BACKGROUND: Isothermal amplification-based tests were developed as rapid, low-cost, and simple alternatives to real-time reverse transcriptase-polymerase chain reaction (RT-PCR) tests for SARS-COV-2 detection. METHODS: Clinical performance of two isothermal amplification-based tests (Atila Biosystems iAMP COVID-19 detection test and OptiGene COVID-19 Direct Plus RT-LAMP test) was compared to clinical RT-PCR assays using different sampling strategies. A total of 1378 participants were tested across four study sites. RESULTS: Compared to standard of care RT-PCR testing, the overall sensitivity and specificity of the Atila iAMP test for detection of SARS-CoV-2 were 76.2% and 94.9%, respectively, and increased to 88.8% and 89.5%, respectively, after exclusion of an outlier study site. Sensitivity varied based on the anatomic collected site. Sensitivity for nasopharyngeal was 65.4% (range across study sites:52.8%-79.8%), mid-turbinate 88.2%, saliva 55.1% (range across study sites:42.9%-77.8%) and anterior nares 66.7% (range across study sites:63.6%-76.5%). The specificity for these anatomic collection sites ranged from 96.7% to 100%. Sensitivity improved in symptomatic patients (overall 82.7%) and those with a higher viral load (overall 92.4% for ct≤25). Sensitivity and specificity of the OptiGene Direct Plus RT-LAMP test, conducted at a single study-site, were 25.5% and 100%, respectively. CONCLUSIONS: The Atila iAMP COVID test with mid-turbinate sampling is a rapid, low-cost assay for detecting SARS-COV-2, especially in symptomatic patients and those with a high viral load, and could be used to reduce the risk of SARS-COV-2 transmission in clinical settings. Variation of performance between study sites highlights the need for site-specific clinical validation of these assays before clinical adoption.

Multisite Clinical Validation of Isothermal Amplification-Based SARS-CoV-2 Detection Assays Using Different Sampling Strategies.

Isothermal amplification-based tests have been introduced as rapid, low-cost, and simple alternatives to real-time reverse transcriptase PCR (RT-PCR) tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection. The clinical performance of two isothermal amplification-based tests (Atila Biosystems iAMP coronavirus disease of 2019 [COVID-19] detection test and OptiGene COVID-19 direct plus RT-loop-mediated isothermal amplification [LAMP] test) was compared with that of clinical RT-PCR assays using different sampling strategies. A total of 1,378 participants were tested across 4 study sites. Compared with standard of care RT-PCR testing, the overall sensitivity and specificity of the Atila iAMP test for detection of SARS-CoV-2 were 76.2% and 94.9%, respectively, and increased to 88.8% and 89.5%, respectively, after exclusion of an outlier study site. Sensitivity varied based on the anatomic site from which the sample was collected. Sensitivity for nasopharyngeal sampling was 65.4% (range across study sites, 52.8% to 79.8%), for midturbinate was 88.2%, for saliva was 55.1% (range across study sites, 42.9% to 77.8%), and for anterior nares was 66.7% (range across study sites, 63.6% to 76.5%). The specificity for these anatomic collection sites ranged from 96.7% to 100%. Sensitivity improved in symptomatic patients (overall, 82.7%) and those with a higher viral load (overall, 92.4% for cycle threshold [CT] of ≤25). Sensitivity and specificity of the OptiGene direct plus RT-LAMP test, which was conducted at a single study site, were 25.5% and 100%, respectively. The Atila iAMP COVID test with midturbinate sampling is a rapid, low-cost assay for detecting SARS-CoV-2, especially in symptomatic patients and those with a high viral load, and could be used to reduce the risk of SARS-CoV-2 transmission in clinical settings. Variation of performance between study sites highlights the need for site-specific clinical validation of these assays before clinical adoption. IMPORTANCE Numerous SARS-CoV-2 detection assays have been developed and introduced into the market under emergency use authorizations (EUAs). EUAs are granted primarily based on small studies of analytic sensitivity and specificity with limited clinical validations. A thorough clinical performance evaluation of SARS-CoV-2 assays is important to understand the strengths, limitations, and specific applications of these assays. In this first large-scale multicentric study, we evaluated the clinical performance and operational characteristics of two isothermal amplification-based SARS-CoV-2 tests, namely, (i) iAMP COVID-19 detection test (Atila BioSystems, USA) and (ii) COVID-19 direct plus RT-LAMP test (OptiGene Ltd., UK), compared with those of clinical RT-PCR tests using different sampling strategies (i.e., nasopharyngeal, self-sampled anterior nares, self-sampled midturbinate, and saliva). An important specific use for these isothermal amplification-based, rapid, low-cost, and easy-to-perform SARS-CoV-2 assays is to allow for a safer return to preventive clinical encounters, such as cancer screening, particularly in low- and middle-income countries that have low SARS-CoV-2 vaccination rates.

Síntesis de evidencia. Covid persistente / Evidence synthesis. persistent covid

El término Covid persistente fue utilizado por primera vez por la Dra. Elisa Perego, como un hashtag de Twitter en mayo de 2020. Describía su propia experiencia de una condición cíclica multifásica, que difería de la evolución clínica característica de Covid-19 tanto en sintomatología como en tiempo. El término Covid persistente o 'Long Covid' tiene varios nombres dependiendo de la literatura consultada: 'secuelas post-agudas de Covid-19', 'Covid¬-19 en curso', 'síndrome crónico de Covid', 'Covid de larga distancia' (Long haulers) y 'condición post-Covid-19', esta última es la utilizada por la Organización Mundial de la Salud (OMS) y todas son consideradas por los Centros para el Control y la Prevención de Enfermedades (CDC) como 'condiciones pos Covid. Aún no existe consenso en cuanto al reconocimiento de Covid persistente como entidad clínica, así como tampoco en cuanto a su nombre y criterios diagnósticos. Sin embargo, dada la alta prevalencia de la sintomatología a la que se le asocia, es imperativo que los servicios y las políticas de salud prioricen su atención. A la vez, es necesario efectuar estudios a futuro para identificar en detalle los diferentes subtipos de Covid persistente y, permitir así, su atención médica estratificada sin que los servicios de salud no se vean abrumados.

The term persistent Covid was used for the first time by Dr. Elisa Perego, as a Twitter hashtag in May 2020. It described her own experience of a multiphasic cyclical condition, which differed from the characteristic clinical evolution of Covid-19 both in symptomatology as in time The term persistent Covid or 'Long Covid' has several names depending on the literature consulted: 'post-acute sequelae of Covid-19', 'Covid¬-19 in progress', 'chronic Covid syndrome', 'Long-distance Covid ' (Long haulers) and 'post-Covid-19 condition', the latter is the one used by the World Health Organization (WHO) and all are considered by the Centers for Disease Control and Prevention (CDC) as ' post covid conditions. There is still no consensus regarding the recognition of persistent Covid as a clinical entity, nor regarding its name and diagnostic criteria. However, given the high prevalence of the symptoms to which it is associated, it is imperative that health services and policies prioritize care. At the same time, it is necessary to carry out future studies to identify in detail the different subtypes of persistent Covid and, thus, allow their stratified medical care without the health services being overwhelmed.

Recomendaciones de tamizaje para cáncer de mama / Screening recommendations for breast cancer

El cáncer de mama no es una enfermedad transmisible ni infecciosa. A diferencia de algunos tipos de cáncer que tienen causas relacionadas con infecciones, como la infección por el virus del papiloma humano (VPH) y el cáncer de cuello uterino, no se conocen infecciones virales o bacterianas relacionadas con el desarrollo del cáncer de mama. Aproximadamente la mitad de los cánceres de mama se desarrollan en mujeres que no tienen un factor de riesgo de cáncer de mama identificable aparte del sexo (mujeres) y la edad (mayores de 40 años). Ciertos factores aumentan el riesgo de cáncer de mama, incluidos el aumento de la edad, la obesidad, el consumo nocivo de alcohol, los antecedentes familiares de cáncer de mama, los antecedentes de exposición a la radiación, los antecedentes reproductivos (como la edad en que comenzaron los períodos menstruales y la edad del primer embarazo), el consumo de tabaco y terapia hormonal posmenopáusica. Las pruebas recomendadas como tamizaje del cáncer de mama deben individualizarse según las siguientes características encontradas en cada paciente: edad, presencia o ausencia de factores de riesgo y densidad mamaria

Breast cancer is not a communicable or infectious disease. Unlike some cancers that have infection-related causes, such as human papillomavirus (HPV) infection and cervical cancer, there are no known viral or bacterial infections associated with the development of breast cancer. About half of breast cancers develop in women who do not have an identifiable risk factor for breast cancer other than gender (female) and age (over 40). Certain factors increase the risk of breast cancer, including increasing age, obesity, harmful use of alcohol, family history of breast cancer, history of radiation exposure, reproductive history (such as age at menstrual periods began and age at first pregnancy), tobacco use, and postmenopausal hormone therapy. The tests recommended for breast cancer screening must be individualized according to the following characteristics found in each patient: age, presence or absence of risk factors, and breast density.

Síntesis de evidencia. Opciones terapéuticas contra COVID-19 / Evidence synthesis. Therapeutic options against COVID-19

La enfermedad Covid-19, causada por el virus SARS-CoV-2, ha generado la necesidad de desarrollar y reutilizar estrategias terapéuticas que permitan el manejo adecuado y oportuno de esta infección viral. A nivel mundial, cada semana se registran nuevas investigaciones sobre las opciones terapéuticas contra Covid-19 y al momento, solo se han identificado efectos beneficiosos en algunos anticuerpos monoclonales, los glucocorticoides, los corticosteroides inhalados, el tocilizumab y el baricitinib, fundamentados con evidencia de certeza moderada a alta. Este documento tiene como objetivo presentar la evidencia disponible sobre las opciones terapéuticas contra Covid-19 a partir de mayo de 2021. Se presentan dos tablas, la primera, resume la descripción de cada medicamento y la conclusión con respecto a su uso como tratamiento contra el SARS-CoV-2, de acuerdo con la evidencia disponible al momento; en la segunda, se muestra esta evidencia. Se evaluó la calidad de la evidencia de los artículos según los parámetros establecidos por el Joanna Briggs Institute/University of Adelaide de Australia. En el caso de las revisiones sistemáticas y/o meta-análisis, se utilizó la herramienta Amstar 2

The Covid-19 disease, caused by the SARS-CoV-2 virus, has generated the need to develop and reuse therapeutic strategies that allow the adequate and timely management of this viral infection. Globally, new research on therapeutic options against Covid-19 is reported every week and, to date, beneficial effects have only been identified for some monoclonal antibodies, glucocorticoids, inhaled corticosteroids, tocilizumab and baricitinib, supported by evidence from moderate to high certainty. This document aims to present the available evidence on therapeutic options against Covid-19 as of May 2021. Two tables are presented, the first, summarizes the description of each drug and the conclusion regarding its use as a treatment against Covid-19. SARS-CoV-2, according to the evidence available at the time; in the second, this evidence is shown. The quality of the evidence of the articles was evaluated according to the parameters established by the Joanna Briggs Institute/University of Adelaide in Australia. In the case of systematic reviews and/or meta-analyses, the Amstar 2 tool was used

Opinión técnica: Uso de vacunas contra COVID-19 en mujeres embarazadas y mujeres que lactan / Technical Opinion: Use of COVID-19 Vaccines in Pregnant and Lactating Women

A nivel mundial las políticas sobre la vacunación contra el Covid-19 durante el embarazo varían ampliamente. Mientras 41 paises recomiendan no hacerlo, 91 paises tienen políticas que permiten que algunas mujeres embarazadas reciban las vacunas. La evidencia sugiere que las mujeres embarazadas tienen mayor riesgo de desarrollar COVID-19 grave.

Globally, policies on vaccinating against Covid-19 during pregnancy vary widely. While 41 countries recommend against doing so, 91 countries have policies that allow some pregnant women to receive the vaccines. Evidence suggests that pregnant women are at higher risk of developing severe COVID-19

Opciones terapéuticas contra el Covid-19 / Therapeutic options against Covid-19

Este documento tiene como objetivo presentar la evidencia disponible sobre las opciones terapeutas contra el Covid-19. Se presentan 2 Tablas, la primera resume la descripción de cada medicamento y la conclusión con respecto a su uso como tratamiento contra el SARS-Covid-2, de acuerdo con la evidencia disponible al momento y en la segunda tabla se muestra esta evidencia

This document aims to present the available evidence on the therapeutic options against Covid-19. Two tables are presented, the first one summarizes the description of each drug and the conclusion regarding its use as a treatment against SARS-Covid-2, according to the evidence available at the time and the second table shows this evidence