[The new generation of messenger RNA (mRNA) vaccines against influenza]. / La nueva generación de vacunas de ARN mensajero (ARNm) frente a la gripe.

Today there are multiple types of flu vaccines. The emergence of nucleic acid technology used in vaccines against SARS-CoV-2 suggests its future application against this infection. Against influenza, two types of vaccines have been developed based on messenger RNA (mRNA): conventional or non-replicative and self-amplifying or replicative (auRNA), both included in lipid nanoparticles. Animal studies carried out with the former have shown their strong capacity to induce Th-1 antibodies and cellular immunity against influenza haemagglutinin (HA) with few side effects. Human trials have shown 87% seroconversion and 100% seroprotection. The auRNA vaccines have obtained similar results in animals but at a concentration 64 times lower than the conventional one. Vaccines based on mRNA platforms meet the WHO requirements for next generation influenza vaccines.

Varicella precipitating febrile ulceronecrotic Mucha-Habermann disease.

We report a 9-year-old boy with skin lesions clinically and histologically compatible with pityriasis lichenoides et varioliformis acuta that evolved to the severe variant febrile ulceronecrotic Mucha-Habermann disease and finally to pityriasis lichenoides chronica. Varicella-zoster virus (VZV) was isolated in culture medium from the skin lesions and serum serology was positive for VZV. This is the first time that a virus has been isolated in culture in this condition.

The new generation of messenger RNA (mRNA) vaccines against influenza.

Today there are multiple types of flu vaccines. The emergence of nucleic acid technology used in vaccines against SARS-CoV-2 suggests its future application against this infection. Against influenza, two types of vaccines have been developed based on messenger RNA (mRNA): conventional or non-replicative and self-amplifying or replicative (auRNA), both included in lipid nanoparticles. Animal studies carried out with the former have shown their strong capacity to induce Th-1 antibodies and cellular immunity against influenza haemagglutinin (HA) with few side effects. Human trials have shown 87% seroconversion and 100% seroprotection. The auRNA vaccines have obtained similar results in animals but at a concentration 64 times lower than the conventional one. Vaccines based on mRNA platforms meet the WHO requirements for next generation influenza vaccines.

[Vaccines against monkeypox]. / Vacunas frente a la viruela del mono (monkeypox).

The monkeypox virus is a virus that has 90% genomic homology with the human (smallpox), but it is naturally transmitted between different wild animal reservoirs and is considered a zoonosis. Throughout the 20th century, different vaccines based on the vaccinia poxvirus were developed and used for vaccination against smallpox. After the eradication of smallpox, these vaccines were no longer used. Current vaccines against monkeypox virus are classified by the WHO as replicative (ACAM2000), minimally replicative (LC16m8) and non-replicative (MVA-BN), the latter being the one currently used. The 2022 extra-African monkeypox virus epidemic has highlighted the lack of vaccines with proven efficacy and low reactogenicity. It is considered that the use of this vaccine in the current outbreak may play a role in the prevention or attenuation of the disease as pre-exposure prophylaxis in close contacts of confirmed cases.

Vaccines against monkeypox.

The monkeypox virus is a virus that has 90% genomic homology with the human (smallpox), but it is naturally transmitted between different wild animal reservoirs and is considered a zoonosis. Throughout the 20th century, different vaccines based on the vaccinia poxvirus were developed and used for vaccination against smallpox. After the eradication of smallpox, these vaccines were no longer used. Current vaccines against monkeypox virus are classified by the WHO as replicative (ACAM2000), minimally replicative (LC16m8) and non-replicative (MVA-BN), the latter being the one currently used. The 2022 extra-African monkeypox virus epidemic has highlighted the lack of vaccines with proven efficacy and low reactogenicity. It is considered that the use of this vaccine in the current outbreak may play a role in the prevention or attenuation of the disease as pre-exposure prophylaxis in close contacts of confirmed cases.

El virus de la viruela de los monos es un virus que presenta un 90% de homología genómica con el humano (smallpox), pero se trasmite de forma natural entre diferentes reservorios animales salvajes y es considerado una zoonosis. A lo largo del siglo XX se desarrollaron diferentes vacunas basadas en el poxvirus vaccinia que fueron utilizadas para la vacunación frente a la viruela humana. Tras la erradicación de la viruela humana estas vacunas dejaron de utilizarse. Las vacunas actuales frente a la viruela de los monos se clasifican por la OMS como replicativas (ACAM2000), mínimamente replicativas (LC16m8) y no replicativas (MVA-BN), siendo esta última la utilizada en la actualidad. La epidemia extraafricana de viruela de los monos de 2022 ha puesto en evidencia la falta de vacunas de eficacia demostrada y de baja reactogenicidad. Se considera que la utilización de esta vacuna en el brote actual puede desempeñar un papel en la prevención o atenuación de la enfermedad como profilaxis preexposición en contactos estrechos de casos confirmados.

Circulation of other respiratory viruses and viral co-infection during the 2009 pandemic influenza.

Coinciding with the pandemic wave of the influenza A(H1N1)pdm09 virus, other respiratory viruses have co-circulated in our area and were responsible for many acute respiratory infections and influenza-like illness (ILI). Apart from the pandemic virus that was responsible for most ILI cases, incidence rates of other viruses have varied among geographical areas. In general, human rhinovirus was the most frequent among individuals from the community, and respiratory syncytial virus among hospitalized patients. Detection rates of other respiratory viruses such as human metapneumovirus, adenovirus or parainfluenza viruses have been much lower. On the basis of an interference mechanism, human rhinovirus may contribute to modulate the pandemic wave, although available data are not conclusive to support this hypothesis. In contrast, the epidemic wave of respiratory syncytial virus during 2009-2010 was similar to previous seasons. Overall, incidence rates of respiratory viruses other than influenza did not change significantly during the pandemic season compared to other seasons. No association has been found between coinfection of pandemic influenza and other respiratory viruses with the prognosis of patients with influenza. The involvement of clinical virology laboratories in the etiological diagnosis of ILI cases has improved and has optimized diagnostic procedures.

Surveillance for Enteroviruses Associated with Hand, Foot, and Mouth Disease, and Other Mucocutaneous Symptoms in Spain, 2006-2020.

Hand, foot, and mouth disease (HFMD) is a mild illness caused by enteroviruses (EV), although in some Asian countries, large outbreaks have been reported in the last 25 years, with a considerable incidence of neurological complications. This study describes epidemiological and clinical characteristics of EV infections involved in HFMD and other mucocutaneous symptoms from 2006 to 2020 in Spain. EV-positive samples from 368 patients were included. EV species A were identified in 85.1% of those typed EV. Coxsackievirus (CV) A6 was the prevalent serotype (60.9%), followed by EV-A71 (9.9%) and CVA16 (7.7%). Infections affected children (1-6 years old) mainly, and show seasonality with peaks in spring-summer and autumn. Clinical data indicated few cases of atypical HFMD as well as those with neurological complications (associated with the 2016 EV-A71 outbreak). Phylogenetic analysis of CVA6 VP1 sequences showed different sub-clusters circulating from 2010 to present. In conclusion, HFMD or exanthemas case reporting has increased in Spain in recent years, probably associated with an increase in circulation of CVA6, although they did not seem to show greater severity. However, EV surveillance in mucocutaneous manifestations should be improved to identify the emergence of new types or variants causing outbreaks and more severe pathologies.

Development and implementation of influenza a virus subtyping and detection of genotypic resistance to neuraminidase inhibitors.

Influenza virus hemagglutinin and neuraminidase, surface glycoproteins with an essential role in viral pathogenesis, are important antigen determinants and essential markers for epidemiological surveillance. Neuraminidase is also a suitable target for designing antiviral drugs. The introduction into clinical practice of neuraminidase inhibitors and the development of random point mutations have increased the emergence of drug-resistant viruses. A universal RT nested PCR-based system has been developed for subtyping H1, H3, N1 and N2, in influenza A viruses of human or animal origin. The subsequent sequencing and analysis of the hemagglutinin and neuraminidase templates reveal antigenic and receptor binding changes in the HA1 subunit and mutations of clinical relevance concerning resistance to neuraminidase inhibitors. The specificity and sensitivity of the method were evaluated using 113 influenza A isolates, 105 influenza A positive respiratory samples obtained from patients and 29 prototype strains of both human and animal origin. The resulting analytical sensitivity of the subtyping techniques is one to at least 100 molecules of cloned DNA product in a final reaction volume of 50 microl. In the course of implementing the method, two H1N1 isolates with the H274Y mutation in the neuraminidase segment have been detected and their molecular features analyzed. The emergence of influenza virus resistance makes the neuraminidase genetic characterization and surveillance activities to detect antiviral resistance necessary.

[Comparison study of a real-time reverse transcription polymerase chain reaction assay with an enzyme immunoassay and shell vial culture for influenza A and B virus detection in adult patients]. / Estudio comparativo entre una técnica de reacción en cadena de la polimerasa en transcripción reversa en tiempo real, un método de enzimoinmunoanálisis y el cultivo shell-vial en la detección de virus gripales A y B en pacientes adultos.

INTRODUCTION: The age of the patients and the type of sample are major problems in the diagnosis of influenza. Most available diagnostic techniques are highly effective in pediatric patients and in nasopharyngeal aspirates. However, in the adult population and using throat swabs, these techniques are much less reliable. AIM: We performed a prospective study comparing the efficacy of a commercial real-time reverse transcription PCR assay (RT-PCR) with that of an enzyme immunoassay (EIA) or shell vial culture (SV) in the detection of influenza A and B viruses in 125 throat swabs from adults with clinically suspected influenza during the 2007-2008 flu season. MATERIAL AND METHODS: Throat swabs were subjected to rapid antigen detection for influenza viruses by means of a commercial dot-blot EIA. For the RT-PCR technique, RNA was extracted from 200 microL of each sample by the automated extraction system, EZ1 virus minikit (version 2.0). Genomic amplification of the extracted viral RNA was carried out using the OneStep RT-PCR FluA+FluB automated system with the SmartCycler amplification system. Each sample was inoculated into 2 SV of the MDCK cell line. Turnaround times were calculated from the time specimens were received in the laboratory to the time the result was reported to clinicians. RESULTS: The EIA system detected 27 (21.6%) positive samples, RT-PCR 62 (49.6%) positive samples, and SV 56 (44.8%) positive samples. Among the 62 positive samples, EIA detected 27 (43.5%), RT-PCR 62 (100%) and SV 56 (90.3%). With the use of RT-PCR, 38.4% of the adults studied were diagnosed on the same day samples were received. Among the total, 67.2% of diagnostic results were obtained within the first 24 hours; turnaround time was 1.1 days. CONCLUSION: The real-time RT-PCR method studied displayed high sensitivity and specificity in the detection of influenza virus in adult patients, when compared with the conventional techniques. With real-time RT-PCR, large numbers of samples can be rapidly tested and results provided the same day samples are received.

Enterovirus D68-associated respiratory and neurological illness in Spain, 2014-2018.

During 2014, enterovirus D68 (EV-D68) outbreaks were described globally, causing severe respiratory diseases in children and, in some cases, subsequent paralysis. In this study, the type characterization of enterovirus (EV) detected in respiratory illnesses and the epidemiology and clinical association of EV-D68 infections in Spain over a five-year period were described. A total of 546 EV-positive samples from hospitalized patients with respiratory infections were included. EV-D68 was the most frequently detected type (46.6%, 191/410 typed EV). Other EV from species A (25.1%), B (27.8%) and C (0.5%) were also identified. EV-D68 infections were more associated with bronchitis while EV-A/B types were more frequent in upper respiratory illness (p < 0.01). EV-D68 was also detected in patients with neurological symptoms (nine meningitis/meningoencephalitis and eight acute flaccid paralysis cases). Phylogenetic analysis of 3'-VP1 region showed most Spanish EV-D68 sequences from 2014 to 2016 belonged to subclades B2/B3, as other American and European strains circulating during the same period. However, those detected in 2017 and 2018 clustered to the emerged subclade D1. In summary, different EV can cause respiratory infections but EV-D68 was the most prevalent, with several strains circulating in Spain at least since 2014. Association between EV-D68 infection and neurological disease was also described.

EDP-938, un nuevo antiviral con actividad inhibidora frente a la nucleoproteína del virus respiratorio sincitial / EDP-938, a new antiviral with inhibitory activity against the nucleoprotein of the respiratory syncytial virus

La ausencia de una vacuna eficaz frente al virus respiratorio sincitial (VRS) ha determinado el desarrollo de diversos fármacos con capacidad para inhibir o bloquear su actividad replicadora. Los de primera generación, denominados inhibidores de la fusión, se fijan a la proteína F de la superficie viral y evitan la unión y entrada del virus en la célula. Sin embargo su baja eficacia ha determinado el inicio de los estudios con los compuestos de segunda generación capaces de unirse o bloquear la nucleoproteína (N); la mayoría de estos compuestos son análogos de las 1,4-benzodiacepinas. El EDP-938 ha mostrado una elevada eficacia frente al VRS. Los primeros ensayos realizados en humanos han mostrado que este antiviral se absorbe de forma rápida tras su administración oral y presenta una vida media de entre 11-18 horas La administración durante siete días de múltiples dosis orales de hasta 600 mg/día o 300 mg/2 veces al día, no presentaban apenas efectos adversos significativos y disminuía significativamente la carga viral a nivel del tracto respiratorio inferior. (AU)

The absence of an effective vaccine against respiratory syncytial virus (RSV) has led to the development of various drugs with the ability to inhibit or block its replicative activity. The first generation, called fusion inhibitors, bind to the protein on the viral surface and prevent the virus from binding and entering the cell. However, its low efficacy has determined the start of studies with second-generation compounds capable of binding or blocking the nucleoprotein (N); most of these compounds are analogs of 1,4-benzodiazepines. EDP-938 has shown high efficacy against RSV. The first trials in humans have shown that this antiviral is rapidly absorbed after oral administration and has a half-life of between 11-18 hours Administration for seven days of multiple oral doses of up to 600 mg/day or 300 mg/day/twice a day, there were hardly any significant adverse effects and the viral load in the lower respiratory tract decreased significantly. (AU)

Usefulness of Ct value in acute respiratory infections caused by respiratory syncytial virus A and B and influenza virus A (H1N1)pdm09, A (H3N2) and B. / Utilidad del valor Ct en las infecciones respiratorias agudas causadas por el virus respiratorio sincitial A y B y los virus gripales A (H1N1)pdm09, A (H3N2) y B.

INTRODUCTION: Acute respiratory infections of viral cause are very frequent entities. The difficulty in evaluating the detection of a virus in these entities could be solved by determining the viral load. METHODS: A prospective study on the mean Ct value (cycle threshold value) detected against RSV-A, RSV-B and influenza A (H1N1)pdm09, A (H3N2) and B viruses in patients of different origin and age was performed. Detection was performed using a commercial molecular amplification (RT-PCR) technique. RESULTS: Different mean Ct values were detected for each virus. In RSV infections, no differences were observed between those caused by RSV-A or RSV-B in children. Depending on the patient's age, the only statistical significance was observed in those included in the 0-4 month groups for RSV-A and this group and the 5-12 months group for RSV-B (higher values). A lower viral load was detected in adult patients than in paediatric patients. In influenza infections, no statistical significance was observed in the mean values detected in patients from the Red Centinela («sentinel network¼, a Spanish network of doctors aimed at research and surveillance of diseases), those diagnosed in the adult emergency room or in hospital admissions. In the adult patients admitted to the ICU, only a slightly lower mean value was observed in those infected with influenza A (H1N1)pdm09, but without statistical significance. There were no patients admitted to the ICU with influenza B infection. CONCLUSION: The detection of viral load could be a good tool for the evaluation, monitoring and prognosis of acute viral respiratory infections. With the exception of those caused by RSV, no significant differences were observed in influenza infections except in younger paediatric patients.

Comparison of different cell lines and incubation times in the isolation by the shell vial culture of human metapneumovirus from pediatric respiratory samples.

We report a prospective study concerning the efficacy of LLC-MK2 (continuous monkey kidney cell), Hep-2, MDCK (Madin-Darby Canine Kidney), Vero and MRC-5 cell lines, by shell vial assay, and incubation time in the isolation of hMPV from pediatric respiratory samples. The overall sensitivity of the cell lines studied were: 100% for the LLC-MK2, 68.7% for the Hep-2, 28.1% for the Vero, 3.1% for the MDCK and 0% for the MRC-5. Only one strain (3.1%) showed growth in the four cell lines studied and 10 (31.2%) strains only grew in the LLC-MK2 cell line. The analysis of incubation times showed that only 14 strains (43.7%) were able to grow after 3 days of incubation, while all strains (100%) showed growth after 5 days. The use of shell vials with commercial LLC-MK2 cells could be a method for isolating hMPV from respiratory samples in the pediatric population.