Current strategies and perspectives for active and passive immunization against Respiratory Syncytial Virus in childhood

Abstract Objectives: Despite the global impact of the Respiratory Syncytial Virus (RSV) infection in children, only one monoclonal antibody (Palivizumab) has been approved for clinical use. However, advances in the knowledge of RSV immunology may enable the development of safe and effective new vaccines and monoclonal antibodies in a few years. The purpose of this review is to summarize available data on approved and developing passive and active immunizations against RSV in childhood and pregnancy. Data source: A non-systematic review of RSV immunoprophylaxis in childhood and pregnancy was carried out in PubMed, path.org and clinical trial registries, without language restrictions, up to September 2022. Data synthesis: Three monoclonal antibodies and 17 active immunization candidates are under development in phase 1 to 3 clinical studies. Regarding the first group, Nirsevimab is a monoclonal antibody with a prolonged half-life whose approval for clinical use is expected in the next months. Among the vaccines under development, six techniques are being used: protein subunit, viral particles, live attenuated virus, recombinant viral vector, chimeric, and mRNA. The first two approaches are being tested primarily in pregnancy, while the others are being developed for the pediatric population. Conclusion: The approval of extended half-life monoclonal antibodies is the next expected advance in RSV prevention, although the costs may be a barrier to the implementation. Regarding active immunizations, maternal and infant vaccination are complementary strategies and there are many promising candidates in clinical studies using different platforms.

Rhinovirus as the main co-circulating virus during the COVID-19 pandemic in children

Abstract Objective: Changes in the epidemiology of respiratory infections during the restrictions imposed as a response to the coronavirus disease 2019 (COVID-19) pandemic have been reported elsewhere. The present study's aim was to describe the prevalence of a large array of respiratory pathogens in symptomatic children and adolescents during the pandemic in Southern Brazil. Methods: Hospitalized and outpatients aged 2 months to 18 years with signs and symptoms of acute COVID-19 were prospectively enrolled in the study from May to November 2020 in two hospitals in a large metropolitan area in a Brazilian city. All participants performed a real-time PCR panel assessing 20 respiratory pathogens (three bacteria and 17 viruses). Results: 436 participants were included, with 45 of these hospitalized. Rhinovirus was the most prevalent pathogen (216/436) followed by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, 97/436), with a coinfection of these two viruses occurring in 31/436 participants. The remaining pathogens were found in 24 symptomatic participants (adenovirus, n = 6; Chlamydophila pneumoniae, n = 1; coronavirus NL63, n = 2; human enterovirus, n = 7; human metapneu-movirus, n = 2; Mycoplasma pneumoniae, n = 6). Hospitalization was more common among infants (p = 0.004) and those with pathogens other than SARS-CoV-2 (p = 0.001). Conclusion: During the period of social distancing in response to COVID-19, the prevalence of most respiratory pathogens was unusually low. Rhinovirus remained as the main virus co-circulating with SARS-CoV-2. COVID-19 in symptomatic children was less associated with hospitalization than with other respiratory infections in children and adolescents.

Association between obesity and hospitalization in mild COVID-19 adult outpatients in Brazil: a prospective cohort study

ABSTRACT Objective: To evaluate the association between obesity and hospitalization in mild COVID-19 adult outpatients in Brazil. Subjects and methods: Adults with signs and symptoms suggestive of acute SARS-CoV-2 infection who sought treatment in two hospital (public and private) emergency departments were prospectively enrolled. Patients with confirmed COVID-19 at inclusion were followed by phone calls at days D7, D14 and D28. Multivariable logistic regression models were employed to explore the association between obesity and other potential predictors for hospitalization. Results: A total of 1,050 participants were screened, and 297 completed the 28-day follow-up and were diagnosed with COVID-19 by RT-PCR. The median age was 37.2 (IQR 29.7-44.6) years, and 179 (60.0%) were female. The duration of symptoms was 3.0 (IQR 2.0-5.0) days, and 10.0 (IQR 8.0-12.0) was the median number of symptoms at inclusion. Ninety-five (32.0%) individuals had obesity, and 233 (78.5%) had no previous medical conditions. Twenty-three participants (7.7%) required hospitalization during the follow-up period. After adjusting, obesity (BMI ≥ 30.0 kg/m2) (OR = 2.69, 95% CI 1.63-4.83, P < 0.001) and older age (OR = 1.05, 95% CI 1.01-1.09, P < 0.001) were significantly associated with higher risks of hospitalization. Conclusion: Obesity, followed by aging, was the main factor associated with hospital admission for COVID-19 in a young population in a low-middle income country. Our findings highlighted the need to promote additional protection for individuals with obesity, such as vaccination, and to encourage lifestyle changes.

Low performance of a SARS-CoV-2 point-of-care lateral flow immunoassay in symptomatic children during the pandemic

Abstract Objective: to evaluate the accuracy of an antibody point-of-care lateral flow immunoassay (LFI -Wondfo Biotech Co., Guangzhou, China) in a pediatric population. Methods: children and adolescents (2 months to 18 years) with signs and symptoms suggestive of acute SARS-CoV-2 infection were prospectively investigated with nasopharyngeal RT-PCR and LFI at the emergency room. RT-PCR was performed at baseline, and LFI at the same time or scheduled for those with less than 7 days of the clinical picture. Overall accuracy, sensitivity and specificity were assessed, as well as according to the onset of symptoms (7-13 or ≥14 days) at the time of the LFI test. Results: In 175 children included, RT-PCR and LFI were positive in 51 (29.14%) and 36 (20.57%), respectively. The overall sensitivity, specificity, positive and negative predictive value was 70.6% (95%CI 56.2-82.5), 96.8% (95%CI 91.9-99.1), 90.0% (95%CI 77.2-96.0), and 88.9% (95%CI 83.9-92.5), respectively. At 7-13 and ≥14 days after the onset of symptoms, sensitivity was 60.0% (95%CI 26.2-87.8) and 73.2% (95%CI 57.1-85.8) and specificity was 97.9% (95%CI 88.7-99.9) and 96.1% (95%CI 89.0-99.2), respectively. Conclusion: Despite its high specificity, in the present study the sensitivity of LFI in children was lower (around 70%) than most reports in adults. Although a positive result is informative, a negative LFI test cannot rule out COVID-19 in children.

Evaluation of the direct and indirect impact on pneumonia hospitalization after almost a decade of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine in Brazil

Introduction: Pneumococcal pneumonia is a leading cause of severe disease, leading to approximately 2.2 million hospital admissions in 2019 in Brazil. Since 2010, the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine was introduced in Brazil, as part of the National Immunization Program (NIP) with universal access, approximated coverage of 91.4% in 2019. Although studies from many countries are available, there is still a need to understand the effect of the vaccine introduction on the incidence of pneumonia hospitalizations in Brazil.Methods: Data on hospitalization associated with the diagnosis of pneumonia in the population assisted by the Brazilian Public Health System were accessed to fit a time series analysis, which tested the main hypothesis of the influence of vaccination on the trends for the incidence of pneumonia hospitalizations.Results: The post-vaccination period showed a negative trend, reducing 1.75, 0.16, and 0.11 cases per 100,000 inhabitants per month for the groups < 1, 1­4, and 5­9 years old, respectively. In individuals older than 20 years, the post-vaccination period has a positive trend, but not as great as compared trends before the vaccination period. These results indicate a protective herd effect in the older population, nine years after introducing the pneumococcal vaccine in the NIP.Conclusion: Vaccination with pneumococcal conjugated vaccine reduces hospitalizations associated with pneumonia diagnosis in vaccinated and non-vaccinated populations in a sustained and progressive manner.

Diagnostic accuracy of a SARS-CoV-2 rapid test and optimal time for seropositivity according to the onset of symptoms / Acurácia diagnóstica de um teste rápido para SARS-CoV-2 e tempo ótimo para a soropositividade a partir do início dos sintomas / Precisión diagnóstica del test rápido SARS-CoV-2 y período óptimo para la seropositividad según la aparición de síntomas

Point-of-care serological tests for SARS-CoV-2 have been used for COVID-19 diagnosis. However, their accuracy over time regarding the onset of symptoms is not fully understood. We aimed to assess the accuracy of a point-of-care lateral flow immunoassay (LFI). Subjects, aged over 18 years, presenting clinical symptoms suggestive of acute SARS-CoV-2 infection were tested once by both nasopharyngeal and oropharyngeal RT-PCR and LFI. The accuracy of LFI was assessed in periodic intervals of three days in relation to the onset of symptoms. The optimal cut-off point was defined as the number of days required to achieve the best sensitivity and specificity. This cut-off point was also used to compare LFI accuracy according to participants' status: outpatient or hospitalized. In total, 959 patients were included, 379 (39.52%) tested positive for SARS-CoV-2 with RT-PCR, and 272 (28.36%) tested positive with LFI. LFI best performance was achieved after 10 days of the onset of symptoms, with sensitivity and specificity of 84.9% (95%CI: 79.8-89.1) and 94.4% (95%CI: 91.0-96.8), respectively. Although the specificity was similar (94.6% vs. 88.9%, p = 0.051), the sensitivity was higher in hospitalized patients than in outpatients (91.7% vs. 82.1%, p = 0.032) after 10 days of the onset of symptoms. Best sensitivity of point-of-care LFI was found 10 days after the onset of symptoms which may limit its use in acute care. Specificity remained high regardless of the number of days since the onset of symptoms.

Os testes sorológicos no local de atendimento (point-of-care) para a infecção pelo SARS-CoV-2 têm sidos utilizados para o diagnóstico da COVID-19. Entretanto, não está plenamente elucidada a acurácia dos testes ao longo do tempo em relação ao início dos sintomas. Nosso objetivo foi de avaliar a acurácia, no local de atendimento, do imunoensaio de fluxo lateral (LFI). Pacientes com ≥ 18 anos de idade que apresentavam sintomas clínicos sugestivos de infecção aguda pelo SARS-CoV-2 foram testados uma vez com RT-PCR da nasofaringe e orofaringe, além do LFI. A acurácia do LFI foi avaliada com intervalos periódicos de 3 dias a partir do início dos sintomas. O ponto de corte ótimo foi definido como o número necessário de dias para atingir a melhor sensibilidade e especificidade. Esse ponto foi utilizado também para comparar a acurácia do LFI de acordo com a situação do paciente (ambulatorial ou hospitalizado). Foram incluídos 959 pacientes, dos quais 379 (39,52%) testaram positivos para SARS-CoV-2 pelo RT-PCR e 272 (28,36%) pelo LFI. Foi atingido o melhor desempenho para o LFI com 10 dias a partir do início dos sintomas, com sensibilidade e especificidade de 84,9% (IC95%: 79,8-89,1) e 94,4% (IC95%: 91,0-96,8), respectivamente. Embora a especificidade não tenha sido diferente entre os grupos de pacientes (94,6% vs. 88,9%, p = 0,051), a sensibilidade foi mais alta nos pacientes hospitalizados que nos ambulatoriais (91,7% vs. 82,1%, p = 0,032) no dia 10 depois do início dos sintomas. A melhor sensibilidade do LFI no local de atendimento ocorre 10 dias depois do início dos sintomas, o que pode limitar seu uso no atendimento agudo. A especificidade permanece alta, independentemente do número de dias desde o início dos sintomas.

Los puestos de atención para pruebas serológicas del SARS-CoV-2 han sido usado para la diagnosis de la COVID-19. No obstante, su precisión a lo largo del tiempo, en lo que respecta a la aparición de los síntomas, no se ha comprendido completamente. Nuestro objetivo fue evaluar la precisión de un puesto de atención de inmunoanálisis de flujo lateral (LFI). Se hizo pruebas a individuos ≥ 18 años, presentando síntomas clínicos compatibles con una infección aguda de SARS-CoV-2, tanto vía nasofaríngea y orofaríngea RT-PCR, como LFI. La precisión de LFI fue evaluada en intervalos periódicos de 3 días con respecto a la aparición de los síntomas. El punto óptimo de corte se definió como el número de días requerido para alcanzar la mejor sensibilidad y especificidad. Este punto también se usó para comparar la precisión del LFI, según el estatus de los participantes: ambulatorios u hospitalizados. Se incluyeron a 959 pacientes, 379 (39,52%) dieron positivo en las pruebas de SARS-CoV-2 RT-PCR, y 272 (28,36%) fueron positivos en los LFI. Se alcanzó el mejor rendimiento de los LFI tras 10 días de la aparición de los síntomas, con una sensibilidad y especificidad de un 84,9% (IC95%: 79,8-89,1) y 94,4% (IC95%: 91,0-96,8), respectivamente. A pesar de que la especificidad no fue diferente (94,6% vs. 88,9%, p = 0,051), la sensibilidad fue mayor en pacientes hospitalizados que en los ambulatorios (91,7% vs. 82,1%, p = 0,032) tras 10 días desde la aparición de los síntomas. La mejor sensibilidad LFI del puesto de cuidado se produce tras 10 días de la aparición de los síntomas, lo que quizás limite su uso en el cuidado de urgencias. La especificidad permanece alta independientemente del número de días desde la aparición de los síntomas.

Características clínicas e preditores de ventilação mecânica em pacientes com COVID-19 hospitalizados no sul do país / Clinical characteristics and predictors of mechanical ventilation in patients with COVID-19 hospitalized in Southern Brazil

RESUMO Objetivo: Descrever as características clínicas e os preditores de ventilação mecânica em pacientes adultos internados com COVID-19. Métodos: Conduziu-se um estudo de coorte retrospectiva com inclusão de pacientes hospitalizados entre 17 de março e 3 de maio de 2020, que tiveram o diagnóstico de infecção pelo SARS-CoV-2. As características clínicas e demográficas foram extraídas de registros em prontuário eletrônico. Resultados: Incluíram-se no estudo 88 pacientes consecutivos. A mediana da idade dos pacientes foi de 63 anos (IQR: 49 - 71); 59 (67%) pacientes eram do sexo masculino, 65 (86%) tinham educação universitária e 67 (76%) tinham, no mínimo, uma comorbidade. Dentre eles, 29 (33%) pacientes foram admitidos à unidade de terapia intensiva, 18 (20%) necessitaram de ventilação mecânica e nove (10,2%) morreram durante a hospitalização. O tempo mediano de permanência na unidade de terapia intensiva e o tempo mediano de ventilação mecânica foram, respectivamente, de 23 e 29,5 dias. Idade acima ou igual a 65 anos foi fator de risco independente para ventilação mecânica (RC: 8,4; IC95% de 1,3 - 55,6; valor de p = 0,02). Conclusão: Nossos achados descrevem a primeira onda de pacientes brasileiros hospitalizados por COVID-19. Em nossa população, idade foi o maior preditor de insuficiência respiratória e necessidade de ventilação mecânica.

Abstract Objective: This study aims to describe the clinical characteristics and predictors of mechanical ventilation of adult inpatients with COVID-19 in a single center. Methods: A retrospective cohort study was performed and included adult inpatients hospitalized from March 17th to May 3rd, 2020, who were diagnosed with SARS-CoV-2 infection. Clinical and demographic characteristics were extracted from electronic medical records. Results: Overall, 88 consecutive patients were included in this study. The median age of the patients was 63 years (IQR 49 - 71); 59 (67%) were male, 65 (86%) had a college degree and 67 (76%) had at least one comorbidity. Twenty-nine (33%) patients were admitted to the intensive care unit, 18 (20%) patients needed mechanical ventilation, and 9 (10.2%) died during hospitalization. The median length of stay in the intensive care unit and the median duration of mechanical ventilation was 23 and 29.5 days, respectively. An age ≥ 65 years was an independent risk factor for mechanical ventilation (OR 8.4 95%CI 1.3 - 55.6 p = 0.02). Conclusion: Our findings describe the first wave of Brazilian patients hospitalized for COVID-19. Age was the strongest predictor of respiratory insufficiency and the need for mechanical ventilation in our population.

OM-85 BV for primary prevention of recurrent airway infections: a pilot randomized, double-blind, placebo-controlled study / OM-85 BV para prevenção primária de infecções recorrentes das vias aéreas: estudo piloto, randomizado, duplo-cego, placebo-controlado

ABSTRACT Objective To compare the frequency of respiratory tract infections in children treated with OM-85 BV and placebo during the 3-month therapy period, and observation for a further 3 months after treatment. Methods A randomized, double-blind, placebo-controlled trial was conducted with 54 children (6 months to 5 years old) with no past history of recurrent respiratory infections attending daycare center. Family members were instructed to administer one capsule per day for 10 consecutive days, for 3 months of OM-85 BV or placebo. Telephone interviews were conducted every 30 days. Results There was no significant difference in the number of respiratory infections between the groups. The mean number of respiratory tract infection in the OM-85 BV Group in the first 3 months was 0.92±0.87, and in the Placebo Group was 0.74±1.02, and at 6 months it was 1.62±1.47 and 1.03±1.34, respectively. Conclusion OM-85 BV was not effective in the primary prevention of respiratory tract infections. Although most authors recommend the use of this immunostimulant in children with a history of recurrent respiratory infections, more studies are needed to define its usefulness in the primary prevention of respiratory infections in healthy children exposed to few risk factors.

RESUMO Objetivo Comparar a frequência de infecções do trato respiratório em crianças tratadas com OM-85 BV e placebo durante o período de terapia de 3 meses, e observação por mais 3 meses após o tratamento. Métodos Foi realizado estudo randomizado, duplo-cego, controlado por placebo com 54 crianças (6 meses a 5 anos) sem história prévia de infecções respiratórias recorrentes, que frequentavam creches. Os membros da família foram instruídos a administrar uma cápsula por dia durante 10 dias consecutivos, durante 3 meses, de OM-85 BV ou placebo. Entrevistas telefônicas foram realizadas a cada 30 dias. Resultados Não houve diferença significativa no número de infecções respiratórias entre os grupos. O número médio de infecções do trato respiratório no Grupo OM-85 BV nos primeiros 3 meses foi de 0,92±0,87 e, no Grupo Placebo, de 0,74±1,02, e aos 6 meses foi de 1,62±1,47 e 1,03±1,34, respectivamente. Conclusão O OM-85 BV não foi eficaz na prevenção primária de infecções do trato respiratório. Embora a maioria dos autores recomende o uso deste imunoestimulante em crianças com história de infecções respiratórias recorrentes, mais estudos são necessários para definir sua utilidade na prevenção primária de infecções respiratórias em crianças saudáveis expostas a poucos fatores de risco.

Microcephaly and Zika virus: a clinical and epidemiological analysis of the current outbreak in Brazil / Microcefalia e vírus Zika: um olhar clínico e epidemiológico do surto em vigênciano Brasil

Abstract Objective: This study aimed to critically review the literature available regarding the Zika virus outbreak in Brazil and its possible association with microcephaly cases. Sources: Experts from Instituto do Cérebro do Rio Grande do Sul performed a critical (nonsystematic) literature review regarding different aspects of the Zika virus outbreak in Brazil, such as transmission, epidemiology, diagnostic criteria, and its possible association with the increase of microcephaly reports. The PubMed search using the key word “Zika virus” in February 2016 yielded 151 articles. The manuscripts were reviewed, as well as all publications/guidelines from the Brazilian Ministry of Health, World Health Organization and Centers for Disease Control and Prevention (CDC – United States). Summary of findings: Epidemiological data suggest a temporal association between the increased number of microcephaly notifications in Brazil and outbreak of Zika virus, primarily in the Brazil's Northeast. It has been previously documented that many different viruses might cause congenital acquired microcephaly. Still there is no consensus on the best curve to measure cephalic circumference, specifically in preterm neonates. Conflicting opinions regarding the diagnosis of microcephaly (below 2 or 3 standard deviations) that should be used for the notifications were also found in the literature. Conclusion: The development of diagnostic techniques that confirm a cause–effect association and studies regarding the physiopathology of the central nervous system impairment should be prioritized. It is also necessary to strictly define the criteria for the diagnosis of microcephaly to identify cases that should undergo an etiological investigation.

Resumo Objetivos: O objetivo deste estudo foi realizar uma revisão crítica da literatura sobre o surto de vírus Zika no Brasil e sua possível associação com casos de microcefalia. Fonte de dados: Especialistas em áreas afins do Instituto do Cérebro do Rio Grande do Sul realizaram uma revisão crítica (não sistemática) da literatura sobre o vírus Zika, suas formas de transmissão, a epidemia no Brasil, critérios diagnósticos e a possível associação com os casos crescentes de microcefalia. O uso da palavra chave “Zika virus” na base de dados do PubMed em fevereiro de 2016, retorna 151 publicações. Estes textos foram revisados assim como todas as publicações e recomendações do Ministério da Saúde, Organização Mundial da Saúde e Centro de Controle de Doenças (CDC – USA). Síntese dos dados: Os dados epidemiológicos sugerem uma relação temporal entre aumento da notificação de casos de microcefalia e o surto de vírus Zika, principalmente no Nordeste do Brasil. Agentes virais comprovadamente podem ser causadores de microcefalia congênita adquirida. Não existe um consenso sobre a melhor curva de perímetro cefálico a ser utilizada, principalmente nos prematuros. Assim como também existem divergências sobre a definição de microcefalia (abaixo de 2 ou 3 desvios padrões) a ser padronizada nas notificações. Conclusão: Deve-se priorizar o desenvolvimento de técnicas diagnósticas que confirmem uma relação causa–efeito e estudos sobre mecanismos da patogênese da infecção pelo Zika no sistema nervoso central. Também é necessário definir e universalizar os critérios diagnósticos para a identificação dos casos de microcefalia que devem ser submetidos à investigação etiológica.

Gastroenterite na infância: diagnóstico e manejo / Gastroenteritis in child: diagnosis and management

Gastroenterite em crianças pode ser causada por vários tipos de patógenos como vírus, bactérias e protozoários. O diagnóstico é baseado em achados clínicos: aumento do número evacuações e pode ter sintomas associados como náuseas, vômitos e cólicas abdominais. O tratamento visa principalmente a reposição das perdas líquidas e, em casos específicos, terapia antimicrobiana.

Gastroenteritis in children can be caused by various types of pathogens such as viruses, bacteria and protozoa. Diagnosis is based on clinical findings: increased number of evacuation and may have associated symptoms such as nausea, vomiting and abdominal cramps. Treatment is aimed mainly the replacement of fluid losses and, in specific cases, antimicrobial therapy.