Cell immunity to SARS-CoV-2 after natural infection and/or different vaccination regimens.

Background: The aim of the study was to evaluate the humoral and cellular immunity after SARS-CoV-2 infection and/or vaccination according to the type of vaccine, number of doses and combination of vaccines. Methods: Volunteer subjects were sampled between September 2021 and July 2022 in Hospital Clínico San Carlos, Madrid (Spain). Participants had different immunological status against SARS-CoV-2: vaccinated and unvaccinated, with or without previous COVID-19 infection, including healthy and immunocompromised individuals. Determination of IgG against the spike protein S1 subunit receptor-binding domain (RBD) was performed by chemiluminescence microparticle immunoassay (CMIA) using the Architect i10000sr platform (Abbott). The SARS-CoV-2-specific T-cell responses were assessed by quantification of interferon gamma release using QuantiFERON SARS-CoV-2 assay (Qiagen). Results: A total of 181 samples were collected, 170 were from vaccinated individuals and 11 from unvaccinated. Among the participants, 41 were aware of having previously been infected by SARS-CoV-2. Vaccinated people received one or two doses of the following vaccines against SARS-CoV-2: ChAdOx1-S (University of Oxford-AstraZeneca) (AZ) and/orBNT162b2 (Pfizer-BioNTech)(PZ). Subjects immunized with a third-booster dose received PZ or mRNA-1273 (Moderna-NIAID)(MD) vaccines. All vaccinees developed a positive humoral response (>7.1 BAU/ml), but the cellular response varied depending on the vaccination regimen. Only AZ/PZ combination and 3 doses of vaccination elicited a positive cellular response (median concentration of IFN- γ > 0.3 IU/ml). Regarding a two-dose vaccination regimen, AZ/PZ combination induced the highest humoral and cellular immunity. A booster with mRNA vaccine resulted in increases in median levels of IgG-Spike antibodies and IFN-γ as compared to those of two-dose of any vaccine. Humoral and cellular immunity levels were significantly higher in participants with previous infection compared to those without infection. Conclusion: Heterologous vaccination (AZ/PZ) elicited the strongest immunity among the two-dose vaccination regimens. The immunity offered by the third-booster dose of SARS-CoV-2 vaccine depends not only on the type of vaccine administered but also on previous doses and prior infection. Previous exposure to SARS-CoV-2 antigens by infection strongly affect immunity of vaccinated individuals.

Monkeypox virus genomic accordion strategies.

The 2023 monkeypox (mpox) epidemic was caused by a subclade IIb descendant of a monkeypox virus (MPXV) lineage traced back to Nigeria in 1971. Person-to-person transmission appears higher than for clade I or subclade IIa MPXV, possibly caused by genomic changes in subclade IIb MPXV. Key genomic changes could occur in the genome's low-complexity regions (LCRs), which are challenging to sequence and are often dismissed as uninformative. Here, using a combination of highly sensitive techniques, we determine a high-quality MPXV genome sequence of a representative of the current epidemic with LCRs resolved at unprecedented accuracy. This reveals significant variation in short tandem repeats within LCRs. We demonstrate that LCR entropy in the MPXV genome is significantly higher than that of single-nucleotide polymorphisms (SNPs) and that LCRs are not randomly distributed. In silico analyses indicate that expression, translation, stability, or function of MPXV orthologous poxvirus genes (OPGs), including OPG153, OPG204, and OPG208, could be affected in a manner consistent with the established "genomic accordion" evolutionary strategies of orthopoxviruses. We posit that genomic studies focusing on phenotypic MPXV differences should consider LCR variability.

Efficacy of delafloxacin alone and incombination with cefotaxime againstcefotaxime non-susceptible invasive isolatesof Streptococcus pneumoniae / Eficacia de delafloxacino solo y en combinación con cefotaxima frente a aislados invasivos de Streptococcus pneumoniae no sensible acefotaxima

Objectives. We assessed the in vitro activity of delafloxacin and the synergy between cefotaxime and delafloxacin among cefotaxime non-susceptible invasive isolates of Streptococcus pneumoniae (CNSSP). Material and methods. A total of 30 CNSSP (cefotaxime MIC > 0.5 mg/L) were studied. Serotyping was performed by the Pneumotest-Latex and Quellung reaction. Minimum inhibitory concentrations (MICs) of delafloxacin, levofloxacin, penicillin, cefotaxime, erythromycin and vancomycin were determined by gradient diffusion strips (GDS). Synergistic activity of delafloxacin plus cefotaxime against clinical S. pneumoniae isolates was evaluated by the GDS cross method. Results. Delafloxacin showed a higher pneumococcal activity than its comparator levofloxacin (MIC50, 0.004 versus 0.75 mg/L and MIC90, 0.047 versus >32 mg/L). Resistance to delafloxacin was identified in 7/30 (23.3%) isolates, belonging to serotypes 14 and 9V. Synergy between delafloxacin and cefotaxime was detected in 2 strains (serotypes 19A and 9V). Antagonism was not observed. Addition of delafloxacin increased the activity of cefotaxime in all isolates. Delafloxacin susceptibility was restored in 5/7 (71.4%) strains. Conclusions. CNSSP showed a susceptibility to delafloxacin of 76.7%. Synergistic interactions between delafloxacin and cefotaxime were observed in vitro among CNSSP by GDS cross method. (AU)

Objetivos. Evaluamos la actividad in vitro de delafloxacino y la sinergia entre cefotaxima y delafloxacino entre aislados invasivos de Streptococcus pneumoniae no sensibles a cefotaxima (SPNSC). Material y métodos. Se estudiaron un total de 30 SPNSC (CIM de cefotaxima > 0,5 mg/L). El serotipado se realizó mediante la reacción Pneumotest-Latex y Quellung. Las concentraciones mínimas inhibitorias (CMI) de delafloxacino, levofloxacino, penicilina, cefotaxima, eritromicina y vancomicina se determinaron mediante tiras de difusión en gradiente (GDS). La actividad sinérgica de delafloxacino y cefotaxima frente aislados clínicos de S. pneumoniae se evaluó mediante el método cruzado GDS. Resultados. Delafloxacino mostró una mayor actividad neumocócica que su comparador levofloxacino (CIM50, 0,004 versus 0,75 mg/L y MIC90, 0,047 versus > 32 mg/L). Se identificó resistencia a delafloxacino en 7/30 (23,3%) aislados, pertenecientes a los serotipos 14 y 9V. Se detectó sinergia entre delafloxacino y cefotaxima en 2 cepas (serotipos 19A y 9V). No se observó antagonismo. La adición de delafloxacino aumentó la actividad de cefotaxima en todos los aislados. La sensibilidad a delafloxacino se restableció en 5/7 (71,4%) cepas. Conclusiones. SPNSC mostraron una susceptibilidad a delafloxacino del 76,7%. Se observaron interacciones sinérgicas in vitro entre delafloxacino y cefotaxima entre SPNSC mediante el método cruzado GDS. (AU)

Incidence of sexually transmitted infections and screening models among pre-exposure prophylaxis users.

INTRODUCTION: There is discussion about the frequency of STI screening among pre-exposure prophylaxis (PrEP) users. The aim of this study was to analyse the incidence of STIs and to evaluate different screening models in order to optimise the follow-up. METHODOLOGY: A prospective study was conducted between 2017 and 2023, including 138 PrEP users in a STI clinic. Participants were tested for STIs every three months. Unscheduled visits were performed for those with STI-related symptoms or for people who were notified for an STI by a sexual partner. We performed a survival analysis of repeated events, estimating the cumulative incidence (CI) and incidence rate (IR). RESULTS: The overall CI by quarterly screening was 8.3 (95% CI: 7.6-9.1) infections per person over six years, with a decreasing trend. The most frequently diagnosed pathogen was Neisseria gonorrhoeae, with a IR of 0.76 (95% CI: 0.68-0.84). If the frequency of screening is reduced to every six months, the IR of STIs is reduced by (95% CI: 0.5-0.66) infections per user per year, and at 12 months by 0.82 (95% CI: 0.73-0.89). In the case of no pharyngeal or urethral screening, IR is reduced by 0.37 (95% CI: 0.32-0.42) infections per person per year and in those over 35 years of age by 0.33 (95% CI: 0.25-0.4). Eliminating unscheduled visits, the reduction in IR is 0.33 (95% CI: 0.24-0.42). CONCLUSIONS: The incidence of STIs among PrEP users is high, especially in the rectum, but it does not increase over time. STI screening could be optimised reducing the frequency of pharyngeal and urethral testing, particularly in those over 35 years of age. It is essential to redistribute health resources for unscheduled visits, which have been shown to be the most cost-effective screening.

Respiratory syncytial virus infection in adults: Differences with influenza.

INTRODUCTION: Respiratory syncytial virus (RSV) causes an acute respiratory illness similar to influenza, although there are few data comparing both of them in adults. The existence of clinical differences between these two infections could have implications for their management. MATERIALS AND METHODS: Retrospective observational cohort study including 63 adults with positive PCR for RSV and 221 for influenza during winter 2018-2019. Epidemiological, clinical characteristics and outcomes were contrasted between both groups. RESULTS: Compared to influenza, RSV-positive patients presented a higher association with active neoplasia (OR=2.9; 95% CI: 1.2-6.9), dependence for basic activities of daily living (OR=3.4; 95% CI: 1.4-8.2) and immunosuppression due to chronic glucocorticoid administration (OR=7.6; 95% CI: 1.6-36.1). At diagnosis, fever was less common (OR=0.3; 95% CI: 0.2-0.7), and C-reactive protein level ≥100mg/l was more frequent (OR=2.1; 95% CI: 1.0-4.5). They developed bacterial co-infection by Staphylococcus aureus in a higher proportion (OR=8.3; 95% CI: 1.5-46.9) and presented a greater need for admission to the intensive care unit (OR=5.4; 95% CI: 1.4-19.2). CONCLUSION: RSV is an important cause of respiratory illness in adults during the influenza season. It especially affects vulnerable patients with chronic underlying diseases, and has a higher morbidity than influenza. For all these reasons, specific detection, prevention and treatment of RSV is necessary in order to reduce the consumption of health care resources due to RSV disease in adults.

Role of Hologic® Panther Aptima™ SARS-CoV-2 assay in the detection of SARS-CoV-2: screening or diagnostic technique? / Papel del ensayo Hologic® Panther Aptima™ SARS-CoV-2 en la detección del SARS-CoV-2: ¿técnica de cribado o de diagnóstico?

During the multiple waves of COVID-19 suffered all over the world, having a rapid and sensitive diagnostic test has be come a priority for microbiology laboratories. The AptimaTM SARS-CoV-2 transcription-mediated amplification (TMA) assay running on the Panther system (Hologic) was presented as a very good option to cover this need. To evaluate this system, 570 respiratory samples were included in the study and were processed both by the Panther (Hologic) system and by qRT PCR (Thermo Fisher Science, Waltham, USA), current assay for the diagnosis of severe acute respiratory syndrome coronavi rus 2 (SARS-CoV-2). A high number of false positives (n=76) was obtained with Panther system (Hologic), but the number of false positives decreases as the relative light units (RLU) val ue increases. These results show that this technique can be a good option for sample screening but checking for positive results should be mandatory, especially those with low RLU values (AU)

Durante las múltiples oleadas de COVID-19 sufridas en todo el mundo, disponer de una prueba diagnóstica rápida y sensible se ha convertido en una prioridad para los laborato transcripción (TMA) AptimaTM SARS-CoV-2 que se ejecuta en el sistema Panther (Hologic) se presentó como una muy bue na opción para cubrir esta necesidad. Para evaluar este sis tema, se incluyeron en el estudio 570 muestras respiratorias y se procesaron tanto por el sistema Panther (Hologic) como por qRT-PCR (Thermo Fisher Science, Waltham, EE. UU.), téc nica utilizada actualmente para el diagnóstico del síndrome respiratorio agudo severo por coronavirus 2 (SARS-CoV-2). Se obtuvo un alto número de falsos positivos (n=76) con el sistema Panther (Hologic), pero el número de falsos positivos disminuye a medida que aumenta el valor de las unidades re lativas de luz (RLU). Estos resultados muestran que esta técnica puede ser una buena opción como técnica de screening, pero la verificación de resultados positivos debería ser obligatoria, especialmente aquellos con valores bajos de RLU (AU)

High performance of the automated ADVIA Centaur Systems SARS-CoV-2 Antigen Assay in nasopharyngeal samples with high viral load / Alto rendimiento del ensayo de antígeno ADVIA Centaur Systems SARS-CoV-2 automatizado en muestras nasofaríngeas con alta carga viral

ADVIA Centaur SARS-CoV-2 Antigen (COV2Ag) Assay (Siemens Healthineers) was evaluated for SARS-CoV-2 detection. A total of 141 nasopharyngeal samples were analyzed by this technique and results were compared with those obtained by quantitative reverse-transcription polymerase chain reaction (RT-PCR). The overall sensitivity and specificity of the test were 68.70% and 70%, respectively. Regarding cycle threshold (Ct) values, the COV2Ag test showed a sensitivity of 93.75% and 100% for nasopharyngeal samples with Ct < 25 and < 20, respectively. ADVIA Centaur COV2Ag Assay is a useful, automated, and rapid technique for early SARS-CoV-2 diagnosis and isolation of the infected individuals, avoiding its transmission.(AU)

Specific Cellular and Humoral Immune Responses to the Neoantigen RBD of SARS-CoV-2 in Patients with Primary and Secondary Immunodeficiency and Healthy Donors.

Patients with antibody deficiency disorders, such as primary immunodeficiency (PID) or secondary immunodeficiency (SID) to B-cell lymphoproliferative disorder (B-CLPD), are two groups vulnerable to developing the severe or chronic form of coronavirus disease caused by SARS-CoV-2 (COVID-19). The data on adaptive immune responses against SARS-CoV-2 are well described in healthy donors, but still limited in patients with antibody deficiency of a different cause. Herein, we analyzed spike-specific IFN-γ and anti-spike IgG antibody responses at 3 to 6 months after exposure to SARS-CoV-2 derived from vaccination and/or infection in two cohorts of immunodeficient patients (PID vs. SID) compared to healthy controls (HCs). Pre-vaccine anti-SARS-CoV-2 cellular responses before vaccine administration were measured in 10 PID patients. Baseline cellular responses were detectable in 4 out of 10 PID patients who had COVID-19 prior to vaccination, perceiving an increase in cellular responses after two-dose vaccination (p < 0.001). Adequate specific cellular responses were observed in 18 out of 20 (90%) PID patients, in 14 out of 20 (70%) SID patients and in 74 out of 81 (96%) HCs after vaccination (and natural infection in some cases). Specific IFN-γ response was significantly higher in HC with respect to PID (1908.5 mUI/mL vs. 1694.1 mUI/mL; p = 0.005). Whereas all SID and HC patients mounted a specific humoral immune response, only 80% of PID patients showed positive anti-SARS-CoV-2 IgG. The titer of anti-SARS-CoV-2 IgG was significantly lower in SID compared with HC patients (p = 0.040), without significant differences between PID and HC patients (p = 0.123) and between PID and SID patients (p =0.683). High proportions of PID and SID patients showed adequate specific cellular responses to receptor binding domain (RBD) neoantigen, with a divergence between the two arms of the adaptive immune response in PID and SID patients. We also focused on the correlation of protection of positive SARS-CoV-2 cellular response to omicron exposure: 27 out of 81 (33.3%) HCs referred COVID-19 detected by PCR or antigen test, 24 with a mild course, 1 with moderate symptoms and the remaining 2 with bilateral pneumonia that were treated in an outpatient basis. Our results might support the relevance of these immunological studies to determine the correlation of protection with severe disease and for deciding the need for additional boosters on a personalized basis. Follow-up studies are required to evaluate the duration and variability in the immune response to COVID-19 vaccination or infection.

Evolution of antibody titers after two doses of mRNA Pfizer-BioNTech vaccine and effect of the third dose in nursing home residents.

OBJECTIVES: We evaluated the IgG antibody titer against SARS-CoV-2 in 196 residents of a Spanish nursing home after the second dose of the BNT162b2 vaccine and the evolution of this titer over time. The role of the third dose of the vaccine on immune-response is also analysed in 115 of participants. METHODS: Vaccine response was evaluated 1, 3 and 6 months after second dose of Pfizer-BioNTech COVID-19 Vaccine and 30 days after booster vaccination. Total anti-RBD (receptor binding domain) IgG immunoglobulins were measured to assess response. Six month after the second dose of vaccine and previously to the booster, T-cell response was also measured in 24 resident with different antibody levels. T-spot Discovery SARS-CoV-2 kit was used to identify cellular immunogenicity. RESULTS: As high as 99% of residents demonstrated a positive serological response after second dose. Only two patients showed no serologic response, two men without records of previous SARS-CoV-2 infection. A higher immune response was associated with prior SARS-CoV-2 infection regardless of the gender or age. The anti-S IgG titers decreased significantly in almost all the participants (98.5%) after six months of vaccination whatever previous COVID-infection. The third dose of vaccine increased antibody titers in all patients, although initial vaccination values were not restored in the majority of cases. CONCLUSION: The main conclusion of the study is that vaccine resulted in good immunogenicity in this vulnerable population. Nevertheless more data are needed on the long-term maintenance of antibody response after booster vaccination.

Infección por virus respiratorio sincitial en adultos: diferencias con la gripe / Respiratory syncytial virus infection in adults: Differences with influenza

Introducción: El virus respiratorio sincitial (VRS) produce una enfermedad respiratoria aguda parecida a la gripe, aunque en adultos existen pocos datos que las comparen. La existencia de diferencias clínicas entre ambas infecciones podría conllevar implicaciones en su manejo. Materiales y métodos: Estudio observacional de cohortes retrospectivo incluyendo 63 adultos con PCR positiva para VRS y 221 para gripe durante el invierno 2018-2019. Se contrastaron las características epidemiológicas, clínicas y desenlaces entre ambos grupos. Resultados: En comparación con la gripe los pacientes VRS positivos asociaron mayor relación con neoplasia activa (OR=2,9; IC 95%: 1,2-6,9), dependencia para las actividades básicas de la vida diaria (OR=3,4; IC 95%: 1,4-8,2) e inmunosupresión por administración crónica de glucocorticoides (OR=7,6; IC 95%: 1,6-36,1). Al diagnóstico era menos común la presencia de fiebre (OR=0,3; IC 95%: 0,2-0,7) y más frecuente un nivel de proteína C reactiva≥100mg/l (OR=2,1; IC 95%: 1,0-4,5). Desarrollaron coinfección bacteriana por Staphylococcus aureus en mayor proporción (OR=8,3; IC 95%: 1,5-46,9) y presentaron una mayor necesidad de ingreso en la unidad de cuidados intensivos (OR=5,4; IC 95%: 1,4-19,2). Conclusión: El VRS es una causa importante de enfermedad respiratoria en adultos durante la época de gripe. Afecta especialmente a pacientes vulnerables con enfermedades crónicas de base, y presenta una morbilidad clínica superior a la gripe. Por todo ello es necesaria la detección, prevención y tratamiento específicos del VRS con el objetivo de reducir el consumo de recursos sanitarios que supone la enfermedad por VRS en adultos.(AU)

Introduction: Respiratory syncytial virus (RSV) causes an acute respiratory illness similar to influenza, although there are few data comparing both of them in adults. The existence of clinical differences between these two infections could have implications for their management. Materials and methods: Retrospective observational cohort study including 63 adults with positive PCR for RSV and 221 for influenza during winter 2018–2019. Epidemiological, clinical characteristics and outcomes were contrasted between both groups. Results: Compared to influenza, RSV-positive patients presented a higher association with active neoplasia (OR=2.9; 95% CI: 1.2–6.9), dependence for basic activities of daily living (OR=3.4; 95% CI: 1.4–8.2) and immunosuppression due to chronic glucocorticoid administration (OR=7.6; 95% CI: 1.6–36.1). At diagnosis, fever was less common (OR=.3; 95% CI: .2–.7), and C-reactive protein level ≥100mg/L was more frequent (OR=2.1; 95% CI: 1.0–4.5). They developed bacterial co-infection by Staphylococcus aureus in a higher proportion (OR=8.3; 95% CI: 1.5–46.9) and presented a greater need for admission to the intensive care unit (OR=5.4; 95% CI: 1.4–19.2). Conclusion: RSV is an important cause of respiratory illness in adults during the influenza season. It especially affects vulnerable patients with chronic underlying diseases, and has a higher clinical morbidity than influenza. For all these reasons, specific detection, prevention and treatment of RSV is necessary in order to reduce the consumption of health care resources due to RSV disease in adults.(AU)

Carbapenemase-Producing Klebsiella pneumoniae in COVID-19 Intensive Care Patients: Identification of IncL-VIM-1 Plasmid in Previously Non-Predominant Sequence Types.

During the COVID-19 pandemic, intensive care units (ICUs) operated at or above capacity, and the number of ICU patients coinfected by nosocomial microorganisms increased. Here, we characterize the population structure and resistance mechanisms of carbapenemase-producing Klebsiella pneumoniae (CP-Kpn) from COVID-19 ICU patients and compare them to pre-pandemic populations of CP-Kpn. We analyzed 84 CP-Kpn isolates obtained during the pandemic and 74 CP-Kpn isolates obtained during the pre-pandemic period (2019) by whole genome sequencing, core genome multilocus sequence typing, plasmid reconstruction, and antibiotic susceptibility tests. More CP-Kpn COVID-19 isolates produced OXA-48 (60/84, 71.4%) and VIM-1 (18/84, 21.4%) than KPC (8/84, 9.5%). Fewer pre-pandemic CP-Kpn isolates produced VIM-1 (7/74, 9.5%). Cefiderocol (97.3-100%) and plazomicin (97.5-100%) had the highest antibiotic activity against pandemic and pre-pandemic isolates. Sequence type 307 (ST307) was the most widely distributed ST in both groups. VIM-1-producing isolates belonging to ST307, ST17, ST321 and ST485, (STs infrequently associated to VIM-1) were detected during the COVID-19 period. Class 1 integron Int1-blaVIM-1-aac(6')-1b-dfrB1-aadAI-catB2-qacEΔ1/sul1, found on an IncL plasmid of approximately 70,000 bp, carried blaVIM-1 in ST307, ST17, ST485, and ST321 isolates. Thus, CP-Kpn populations from pandemic and pre-pandemic periods have similarities. However, VIM-1 isolates associated with atypical STs increased during the pandemic, which warrants additional monitoring and surveillance.

High performance of the automated ADVIA Centaur Systems SARS-CoV-2 Antigen Assay in nasopharyngeal samples with high viral load.

ADVIA Centaur SARS-CoV-2 Antigen (COV2Ag) Assay (Siemens Healthineers) was evaluated for SARS-CoV-2 detection. A total of 141 nasopharyngeal samples were analyzed by this technique and results were compared with those obtained by quantitative reverse-transcription polymerase chain reaction (RT-PCR). The overall sensitivity and specificity of the test were 68.70% and 70%, respectively. Regarding cycle threshold (Ct) values, the COV2Ag test showed a sensitivity of 93.75% and 100% for nasopharyngeal samples with Ct < 25 and < 20, respectively. ADVIA Centaur COV2Ag Assay is a useful, automated, and rapid technique for early SARS-CoV-2 diagnosis and isolation of the infected individuals, avoiding its transmission.

Valoración de dos pruebas inmunocromatográficas para la detección de anticuerpos frente a SARS-CoV-2 / Evaluation of two immunocromatographic tests for the detection of antibodies against SARS-CoV-2

Introducción. Las pruebas serológicas han resultado una herramienta de gran valor en el transcurso de la pandemia por SARS-CoV-2, tanto en la detección, apoyando a los métodos moleculares, como en el seguimiento de la respuesta inmune, provocada por la vacunación o por la infección natural. Dentro de todas estas técnicas, las pruebas rápidas resultan interesantes por su fácil uso, rápida respuesta y bajo coste económico. Material y métodos. Se evaluaron dos técnicas inmunológicas diferentes: Realy Tech y Mikrogen Diagnostik recomLine SARS-CoV-2 IgG. Como técnicas de referencia se utilizaron pruebas automatizadas: SARS-CoV-2 IgG II Quant antibody test y SARS-CoV-IgG assay, ambos de Abbott Diagnostics. Resultados. Mikrogen Diagnostik fue el que, en conjunto, ofreció mejores resultados (S=0,985; E=0,839). Las dos técnicas mostraron buenos valores predictivos positivos, pero los valores predictivos negativos de Realy Tech estuvieron lejos de lo deseable. Conclusiones. Mikrogen Diagnostik recomLine SARS-CoV-2 IgG ofreció muy buenos resultados en la detección de anticuerpos frente a SARS-CoV-2 y podría ser utilizada como alternativa a las técnicas automatizadas. (AU)

Introduction. Serological tests have been a valuable tool during the SARS-CoV-2 pandemic, supporting molecular methods for detection, and monitoring the immune response, caused by vaccination or by natural infection. Within all these techniques, rapid tests are interesting due to their ease of use, rapid response and low cost. Methods. Two different immunological techniques were evaluated: Realy Tech and Mikrogen Diagnostik recomLine SARS-CoV-2 IgG. SARS-CoV-2 IgG II Quant antibody test and SARS-CoV-IgG assay, both from Abbott Diagnostics, were used as reference techniques. Results. Mikrogen Diagnostik recomLine SARS-CoV-2 IgG shows the best results (S=0.985; E=0.839). Three techniques offered good positive predictive values, but Realy Tech and Healgen negative predictive values left to be desired. Conclusions. Mikrogen Diagnostik recomLine SARS-CoV-2 IgG showed good results in the detection of antibodies against SARS-CoV-2 and could be used as an alternative to automated techniques. (AU)

Analysis of Adverse Effects of COVID-19 Vaccines in Spain following Booster Dose.

The present study evaluates the adverse effects of three vaccines: AstraZeneca (Vaxzevria), Pfizer/BioNTech (Comirnaty) and Moderna (Spikevax) according to the dose. From 733 participants collected, the vaccine schedule was as follows: 330 (45%) received a double dose of the AstraZeneca vaccine, 382 (52.1%) received a double dose of Pfizer, 18 (2.5%) received a heterologous prime boost and 3 (0.4%) received a single dose. Pfizer and Moderna vaccines were administered as a third dose in 70 and 121 individuals, respectively. Local and systemic reactions observed in the three vaccines were mild to moderate in severity. Only one AstraZeneca recipient (0.3%) presented a serious adverse effect: blurred vision. Adverse events were more frequent after the first dose of AstraZeneca and after the second dose of Pfizer. As the third dose, Moderna causes more adverse effects than Pfizer regardless of the type of vaccine previously administered, whereas the reactogenicity of a third dose of Pfizer is slightly higher in the group previously vaccinated with Pfizer than in that group with AstraZeneca. In short, secondary effects of the third dose of COVID-19 vaccines were similar to those after dose 2, but their frequency depends on the type of vaccine and the combinations of vaccines.

Monkeypox outbreak in Madrid (Spain): Clinical and virological aspects.

BACKGROUND: Monkeypox is the most prevalent Orthopoxvirus zoonosis infection since the eradication of smallpox. The current multi-country outbreak involves five WHO regions affecting mainly Europe. Accurate clinical and virological aspects of the disease outside endemic areas are needed. METHODS: We performed an observational study of cases diagnosed in Madrid (Spain) (May/June 2022). Confirmation from vesicular lesions swabs, Orthopoxvirus real-time PCR, sequencing, phylogenetic analysis, and direct detection by Electron microscopy was performed. In addition, a structured epidemiological questionnaire was completed systematically to gather sociodemographic, clinical, and behavioral data from all confirmed cases. FINDINGS: We extracted data from 48 patients, all cisgender men. The median age was 35 years (IQR 29 - 44), and 87.5% were MSM. The most prevalent symptoms were the presence of vesicular-umbilicated and pseudo-pustular skin lesions (93.8%), asthenia (66.6%), and fever (52.1%). In addition, the location of the lesions in the genital or perianal area was related to the role in sexual intercourse (p<0.001). Sequencing analysis indicated the virus circulating in Spain belongs to the western African clade. Like the other European cases in the outbreak, the Spanish isolates are a direct descendant of viruses previously detected in Nigeria, the UK, Singapore, and Israel in 2017-2018. CONCLUSIONS: Monkeypox is an emerging infectious disease in Europe where community transmission is reported, mainly in MSM. The first symptom was skin lesions instead of classical fever and rash. The disease follows a self-limited course, and there have been no cases with a serious presentation or severe complications.

Seroprevalence of anti-SARS-CoV-2 IgG antibodies: relationship with COVID-19 diagnosis, symptoms, smoking, and method of transmission.

Aims: The study of SARS-CoV-2 antibodies in the population is a crucial step towards overcoming the COVID-19 pandemic. Seroepidemiological studies allow an estimation of the number of people who have been exposed to the virus, as well as the number of people who are still susceptible to infection. Methods: In total, 13 560 people from Arganda del Rey, Madrid (Spain) were assessed between January and March 2021 for the presence of IgG antibodies, using rapid tests and histories of symptoms compatible with COVID-19. Results: 24.2% of the participants had IgG antibodies and 9% had a positive COVID-19 diagnosis. Loss of smell/taste was the most discriminating symptom of the disease. The main transmitters of infection were found to be household members. Unexpectedly, in smokers, the incidence of positive COVID-19 diagnoses was significantly lower. Additionally, it was found that there was a discrepancy between COVID-19 diagnosis and the presence of IgG antibodies. Conclusions: Rapid anti-IgG tests are less reliable in detecting SARS-CoV-2 infection at an individual level, but are functional in estimating SARS-CoV-2 infection rates at an epidemiological level. The loss of smell/taste is a potential indicator for establishing COVID-19 infection.

A Prospective Study of the Serological, Clinical, and Epidemiological Features of a SARS-CoV-2 Positive Pediatric Cohort.

Background: SARS-CoV-2 was a global pandemic. Children develop a mild disease and may have a different rate of seroconversion compared to adults. The objective was to determine the number of seronegative patients in a pediatric cohort. We also reviewed the clinical−epidemiological features associated with seroconversion. Methods: A multicenter prospective observational study during September−November 2020, of COVID-19, confirmed by reverse transcription-polymerase chain reaction. Data were obtained 4−8 weeks after diagnosis. Blood samples were collected to investigate the humoral response, using three different serological methods. Results: A total of 111 patients were included (98 symptomatic), 8 were admitted to hospital, none required an Intensive Care Unit visit. Median age: 88 months (IQR: 24−149). Median time between diagnosis and serological test: 37 days (IQR: 34−44). A total of 19 patients were non-seroconverters when using three serological techniques (17.1%; 95% CI: 10.6−25.4); most were aged 2−10 years (35%, p < 0.05). Univariate analysis yielded a lower rate of seroconversion when COVID-19 confirmation was not present amongst household contacts (51.7%; p < 0.05). Conclusions: There was a high proportion of non-seroconverters. This is more commonly encountered in childhood than in adults. Most seronegative patients were in the group aged 2−10 years, and when COVID-19 was not documented in household contacts. Most developed a mild disease. Frequently, children were not the index case within the family.

Usefulness of SARS-CoV-2 antigen test sample as input for SARS-CoV-2 RT-PCR analysis.

SARS-CoV-2 rapid detection is of great interest to prevent viral dissemination. In that sense, antigen tests appeared as a very valuable tool to reach this goal. However, it is possible to obtain a negative result in those patients with low viral loads, and consequently, reverse transcription-polymerase chain reaction (RT-PCR) should be performed on samples from patients with a negative antigen test in which there is a strong suspicion of COVID infection. The common diagnostic algorithm involves taking a second sample for RT-PCR testing. This study evaluates the usefulness of the antigen test sample for carrying out RT-PCR analysis when necessary. Results obtained indicate that can be used a unique sample for both antigen test and RT-PCR. This data showed that it is possible to reduce excessive suspected individuals managing and so on increase staff security and patient comfort.

Clinitest rapid COVID-19 antigen test for the diagnosis of SARS-CoV-2 infection: A multicenter evaluation study.

OBJECTIVES: RT-PCR assay is the reference method for diagnosis of COVID-19, but it is also a laborious and time-consuming technic, limiting the availability of testing. Rapid antigen-detection tests are faster and less expensive; however, the reliability of these tests must be validated before they can be used widely. The objective of this study was to determine the performance of the Clinitest Rapid COVID-19 Antigen Test (ClinitestRT) (SIEMENS) for SARS-CoV-2 in nasopharyngeal swab specimens. METHODS: This prospective multicenter study was carried out in three Spanish university hospitals including individuals with clinical symptoms or epidemiological criteria for COVID-19. Only individuals with ≤7 days from the onset of symptoms or from exposure to a confirmed case of COVID-19 were included. Two nasopharyngeal samples were taken to perform the ClinitestRT, as a point-of-care test, and a diagnostic RT-PCR test. RESULTS: Overall sensitivity and specificity for the ClinitestRT among the 450 patients studied were 93.3% (CI 95%: 89.7-96.8) and 99.2% (CI 95%: 97.2-99.8), respectively. Sensitivity in participants with ≤5 days of the clinical course was 93.6% (CI 95%: 89.2-96.3), and in participants who had a CT < 25 for the RT-PCR test was 98.4% (CI 95%: 94.5-99.6). Agreement between techniques was 96.7% (kappa score: 0.93; CI 95%: 0.90-0.97). CONCLUSIONS: The ClinitestRT provides good clinical performance, with more reliable results for patients with a higher viral load. The results must be interpreted based on the local epidemiological context.