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Many recent outbreaks of influenza A (H1N1) in the world, especially in Brazil, it has become clear that the severity of the disease is not known in the same form. On Wednesday, June 7, 2023, Brazil notified the WHO of a fatal case of human infection with a variant of the influenza A(H1N1) virus of swine origin, this case was confirmed in a laboratory in the region of the interior state of Paraná. This is the first human infection caused by an influenza A (H1N1) virus reported in 2023 nationwide in Brazil. To mitigate H1N1 flu in Brazil, we urge the Brazillian government through its Ministry of Health to improve on mass awareness about the signs and symptoms of H1N1 flu among the Brazillians. The Brazillian government should also implement the One Health approach towards the control of H1N1 flu in Brazil, as we believe that these recommendations would go a long way in preventing future cases and the spread of H1N1 flu in Brazil. This article aims to present the clinical presentations of the H1N1 flu and the implications, recommendations and the way forward to protect the Brazilian population against the H1N1 flu.
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BACKGROUND: Hospital-acquired influenza (HAI) is under-recognized despite its high morbidity and poor health outcomes. The early detection of HAI is crucial for curbing its transmission in hospital settings. AIM: This study aimed to investigate factors related to HAI, develop predictive models, and subsequently compare them to identify the best performing machine learning algorithm for predicting the occurrence of HAI. METHODS: This retrospective observational study was conducted in 2022 and included 111 HAI and 73,748 non-HAI patients from the 2011-2012 and 2019-2020 influenza seasons. General characteristics, comorbidities, vital signs, laboratory and chest X-ray results, and room information within the electronic medical record were analysed. Logistic Regression (LR), Random Forest (RF), Extreme Gradient Boosting (XGB), and Artificial Neural Network (ANN) techniques were used to construct the predictive models. Employing randomized allocation, 80% of the dataset constituted the training set, and the remaining 20% comprised the test set. The performance of the developed models was assessed using metrics such as the area under the receiver operating characteristic curve (AUC), the count of false negatives (FN), and the determination of feature importance. RESULTS: Patients with HAI demonstrated notable differences in general characteristics, comorbidities, vital signs, laboratory findings, chest X-ray result, and room status compared to non-HAI patients. Among the developed models, the RF model demonstrated the best performance taking into account both the AUC (83.3%) and the occurrence of FN (four). The most influential factors for prediction were staying in double rooms, followed by vital signs and laboratory results. CONCLUSION: This study revealed the characteristics of patients with HAI and emphasized the role of ventilation in reducing influenza incidence. These findings can aid hospitals in devising infection prevention strategies, and the application of machine learning-based predictive models especially RF can enable early intervention to mitigate the spread of influenza in healthcare settings.
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Infecção Hospitalar , Influenza Humana , Aprendizado de Máquina , Humanos , Influenza Humana/epidemiologia , Influenza Humana/diagnóstico , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Infecção Hospitalar/epidemiologia , Idoso , Adulto , Algoritmos , Curva ROC , Redes Neurais de Computação , Adulto Jovem , Idoso de 80 Anos ou mais , Modelos LogísticosRESUMO
BACKGROUND: During the 2019 severe influenza season, New South Wales (NSW) experienced the highest number of cases in Australia. This study retrospectively investigated the genetic characteristics of influenza viruses circulating in NSW in 2019 and identified genetic markers related to antiviral resistance and potential virulence. METHODS: The complete genomes of influenza A and B viruses were amplified using reverse transcription-polymerase chain reaction (PCR) and sequenced with an Illumina MiSeq platform. RESULTS: When comparing the sequencing data with the vaccine strains and reference sequences, the phylogenetic analysis revealed that most NSW A/H3N2 viruses (n = 68; 94%) belonged to 3C.2a1b and a minority (n = 4; 6%) belonged to 3C.3a. These viruses all diverged from the vaccine strain A/Switzerland/8060/2017. All A/H1N1pdm09 viruses (n = 20) showed genetic dissimilarity from vaccine strain A/Michigan/45/2015, with subclades 6B.1A.5 and 6B.1A.2 identified. All B/Victoria-lineage viruses (n = 21) aligned with clade V1A.3, presenting triple amino acid deletions at positions 162-164 in the hemagglutinin protein, significantly diverging from the vaccine strain B/Colorado/06/2017. Multiple amino acid substitutions were also found in the internal proteins of influenza viruses, some of which have been previously reported in hospitalized influenza patients in Thailand. Notably, the oseltamivir-resistant marker H275Y was present in one immunocompromised patient infected with A/H1N1pdm09 and the resistance-related mutation I222V was detected in another A/H3N2-infected patient. CONCLUSIONS: Considering antigenic drift and the constant evolution of circulating A and B strains, we believe continuous monitoring of influenza viruses in NSW via the high-throughput sequencing approach provides timely and pivotal information for both public health surveillance and clinical treatment.
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Herpesvirus Cercopitecino 1 , Vacinas contra Influenza , Influenza Humana , Humanos , Estudos Retrospectivos , Herpesvirus Cercopitecino 1/genética , Vírus da Influenza A Subtipo H3N2/genética , New South Wales/epidemiologia , Filogenia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Austrália , Estações do Ano , Sequenciamento Completo do GenomaRESUMO
Objective@#To analyze the characteristics of influenza virus detection in an influenza outbreak in schools, so as to provide a strategic basis for the treatment of influenza outbreaks in schools.@*Methods@#A total of 1 702 samples were collected from 52 school influenza outbreaks reported in Linyi City in 2021-2022. The samples were divided into 3 types according to different symptoms during the management of the epidemic [group A:influenzalike illness (ILI) group; group B:mild illness group; group C:close contacts group]. Rt-PCR was used to detect influenza virus nucleic acid in the collected samples. The detection rate of influenza virus in the outbreaks was analyzed by χ2 test.@*Results@#In total, 1 071 samples (62.93%) tested positive for influenza virus nucleic acid. Among them, 610 out of 726 samples (84.02%) were detected in group A, while 331 out of 634 samples (52.21%) were detected in group B. In group C, 130 out of 342 samples (38.01%) tested positive. The differences were statistically significant (χ2=260.71, P<0.01). In group A, males had a detection rate of 80.83% for influenza virus nucleic acid, compared to 91.36% for females. For group B, the rates were 53.31% for males and 50.87% for females. In group C, males had a rate of 30.72%, while females had a rate of 43.92%. Statistical significance for gender differences was observed only in groups A and C (χ2=12.67, 6.25, P<0.05). According to the days of onset, the detection rates of influenza virus nucleic acid among patients with onset 0-6 days were 56.30%, 74.49%, 89.35%, 86.23%, 69.67%, 62.75%, 34.33%, respectively, and the difference was statistically significant (χ2=128.27, P<0.01).@*Conclusions@#Mild cases and close contacts are likely key factors contributing to the prolonged emergence of new cases within classrooms during school influenza outbreaks. The progression of influenza symptoms is related to the risk of transmission.
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BACKGROUND: Co-circulation of SARS-CoV-2 and influenza virus can lead to double epidemics and increased pressure on health systems. To evaluate the effect of both vaccines, we estimated the adjusted vaccine effectiveness (aVE) of influenza and Covid-19 vaccines against related severe disease in the elderly population in Norway during the 2022/2023 season. METHODS: In this population-based cohort study, we included data from the Emergency preparedness register for Covid-19 (Beredt C19) on all individuals ≥ 65 years living in Norway between 3 October 2022 and 20 June 2023. Using Cox-proportional hazard models, we estimated aVE of both influenza and Covid-19 vaccines (bivalent BA.1 and BA.4-5) against associated hospitalisation and death. Vaccine status was included as a time-varying covariate and all models were adjusted for potential confounders, including the other vaccine. RESULTS: We identified 2,437 influenza-associated hospitalisations and 178 deaths, alongside 5,824 Covid-19-associated hospitalisations and 621 deaths. The aVE was highest in the first three months after receiving either vaccine. Against influenza-associated hospitalisation the aVE was 34 % (26 %-42 %) among 65-79-year-olds and 40 % (30 %-48 %) among ≥ 80-year-olds, and 6.6 % (-64 %-47 %) and 37 % (0.5 %-61 %) against influenza-associated death, respectively. The aVE against Covid-19-associated hospitalisation was 65 % (61 %-69 %) among 65-79-year-olds and 55 % (49 %-60 %) among ≥ 80-year-olds (compared to having received the vaccine ≥ 180 days ago). Similarly, the aVE against Covid-19-associated death was 68 % (48 %-80 %) and 78 % (65 %-86 %), respectively. For Covid-19 we show a reduction in aVE with time since dose. CONCLUSION: Covid-19 and influenza vaccines reduced the risk of severe disease in the same high-risk population. Ensuring high uptake of both vaccines could thus limit the overall health care burden.
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COVID-19 , Vacinas contra Influenza , Influenza Humana , Humanos , Idoso , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Vacinas contra COVID-19 , Estudos de Coortes , Eficácia de Vacinas , COVID-19/epidemiologia , COVID-19/prevenção & controle , SARS-CoV-2 , Noruega/epidemiologia , Hospitalização , HospitaisRESUMO
RATIONALE: Several authors have compared COVID-19 infection with influenza in the ICU. OBJECTIVE: This study aimed to compare the baseline clinical profiles, care procedures, and mortality outcomes of patients admitted to the intensive care unit, categorized by infection status (Influenza vs. COVID-19). METHODS: Retrospective observational study. Data were extracted from the Toulouse University Hospital from March 2014 to March 2021. To compare survival curves, we plotted the survival at Day-90 using the Kaplan-Meier curve and conducted a log-rank test. Additionally, we performed propensity score matching to adjust for confounding factors between the COVID-19 and influenza groups. Furthermore, we use the CART model for multivariate analysis. RESULTS: The study included 363 patients admitted to the ICU due to severe viral pneumonia: 152 patients (41.9 %) with influenza and 211 patients (58.1 %) with COVID-19. COVID-19 patients exhibited a higher prevalence of cardiovascular risk factors, whereas influenza patients had significantly higher severity scores (SOFA: 10 [6-12] vs. 6 [3-9], p<0.01 and SAPS II: 51 [35-67] vs. 37 [29-50], p<0.001). Overall mortality rates were comparable between the two groups (27.6 % (n = 42) in the influenza group vs. 21.8 % (n = 46) in the COVID-19 group, p=NS). Mechanical ventilation was more commonly employed in the influenza group (76.3 % (n = 116) vs. 59.7 % (n = 126), p<0.001); however, COVID-19 patients required longer durations of mechanical ventilation (18 [9-29] days vs. 13 [5-24] days, p<0.006) and longer hospital stays (23 [13-34] days vs. 18.5 [9-34.5] days, p = 0.009). The CART analysis revealed that the use of extra renal replacement therapy was the most influential prognostic factor in the influenza group, while the PaO2/FiO2-PEEP ratio played a significant role in the COVID-19 group. CONCLUSIONS: Despite differences in clinical presentation and prognostic factors, the mortality rates at 90 days, after adjusting for confounding factors, were similar between COVID-19 and influenza patients.
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COVID-19 , Influenza Humana , Pneumonia Viral , Humanos , COVID-19/epidemiologia , Influenza Humana/epidemiologia , Unidades de Terapia Intensiva , Respiração Artificial , Estudos RetrospectivosRESUMO
It has been suggested that the outcomes of coronavirus disease 2019 (COVID-19) are better in individuals having recently received an influenza vaccine than in non-vaccinated individuals. We hypothesized that this association depends on the humoral responses against influenza viruses. We aim to assess the relationship between the humoral immunity against influenza and the 3-month all-cause mortality among hospitalized older patients with COVID-19. We performed an exploratory retrospective study of older patients (aged 65 and over) hospitalized for confirmed COVID-19 between November 2020 and June 2021. Previous humoral responses to influenza viruses were assessed using a hemagglutination inhibition assay on routinely collected blood samples. The study's primary outcome was the 3-month all-cause mortality, and the secondary outcomes were severe COVID-19 (oxygen requirement ≥ 6 L/min or ventilatory support) and complications (kidney or heart failure, thrombosis and bacterial infection). In the cohort of 95 patients with COVID-19, immunity against influenza vaccine subtypes/lineages was not significantly associated with 3-month all-cause mortality, with an OR [95%CI] of 0.22 [0.02-1.95] (p = 0.174) for the H1N1pdm09 subtype, 0.21 [0.03-1.24] (p = 0.081) for A/Hong Kong/2671/2019 H3N2 subtype, 1.98 [0.51-8.24] (p = 0.329) for the B/Victoria lineage, and 1.82 [0.40-8.45] (p = 0.437) for the B/Yamagata lineage. Immunity against influenza vaccine subtypes/lineages was also not significantly associated with severity and complication. Immunity against influenza subtypes/lineages included in the 2020-2021 vaccine was not associated with a lower 3-month all-cause mortality among COVID-19 hospitalized patients.Trial registration: The study was approved by a hospital committee with competency for research not requiring approval by an institutional review board (Tours University Medical Center, Tours, France: reference: 2021_015). All patients give the informed consent.
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COVID-19 , Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza , Influenza Humana , Humanos , Idoso , Influenza Humana/prevenção & controle , Estudos Retrospectivos , Vírus da Influenza A Subtipo H3N2RESUMO
BACKGROUND: Despite being a vaccine-preventable disease, influenza remains a major public health threat with vaccine safety concerns reducing vaccine acceptability. Immune responses to vaccines and adverse events may differ between males and females, but most studies do not report results by sex. Using data from clinical trials, we explored sex differences in adverse events following seasonal influenza vaccines. METHODS: We obtained data for phase III randomised controlled trials identified through a systematic review and clinical trials registries, and performed a two-stage meta-analysis. Risk ratios (RR) and 95% confidence intervals (95% CI) comparing solicited reactions in females versus males were pooled using the Mantel-Haenszel method and a random-effects model. We used the ROBINS-I tool to assess risk of bias and the I2 statistic for heterogeneity. Main analysis was stratified by age: 18-64 years and ≥65 years. RESULTS: The dataset for this analysis included 34 343 adults from 18 studies (12 with individual-level data and 6 with aggregate data). There was a higher risk of injection site reactions in females compared with males for both younger and older participants, with RRs of 1.29 (95% CI 1.21 to 1.37) and 1.43 (95% CI 1.28 to 1.60), respectively. Higher risk in females was also observed for systemic reactions, with RRs of 1.25 (95% CI 1.20 to 1.31) and 1.27 (95% CI 1.20 to 1.34) for younger and older participants, respectively. We also observed elevated risks of severe reactions in females, with a higher RR in younger versus older participants for systemic reactions (RRs 2.12 and 1.48, p=0.03, I2=79.7%). RRs were not found to vary between quadrivalent and trivalent vaccines. CONCLUSION: This meta-analysis suggested a higher risk of solicited reactions following influenza vaccines for females compared with males, irrespective of age and vaccine type. Transparent communication of this risk could increase the trust in vaccines and limit vaccine hesitancy. Future studies should report results stratified by sex and explore the role of gender in the occurrence of adverse events.
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Vacinas contra Influenza , Influenza Humana , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Vacinas contra Influenza/efeitos adversos , Influenza Humana/prevenção & controle , Estações do Ano , Caracteres Sexuais , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
OBJECTIVE: This study aimed to evaluate the performance of the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) case definitions for influenza-like illness (ILI) in diagnosing influenza during the 2022-2023 flu season in Mexico. STUDY DESIGN: We conducted a cross-sectional analysis of national epidemiological surveillance data in Mexico, focusing on respiratory viral pathogens. METHODS: We analyzed data from 6027 non-hospitalized patients between 5 and 65 years old who underwent molecular testing for respiratory viral pathogens. The performance of both case definitions was evaluated in terms of sensitivity, specificity, and the area under the receiver operating characteristic (AUROC) curve. RESULTS: Overall, the diagnostic accuracy of the evaluated ILI definitions in identifying influenza patients was low, particularly among older patients. When compared to the CDC, the WHO definition had a lower sensitivity but a higher specificity, resulting in a higher AUROC (P = 0.031) for the WHO criteria. CONCLUSIONS: Our findings suggest that the WHO and CDC ILI case definitions have limited accuracy for diagnosing influenza in non-hospitalized patients and highlight the need for more specific diagnostic tools to improve the detection of influenza cases during the flu season.
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Influenza Humana , Viroses , Estados Unidos , Humanos , Pré-Escolar , Criança , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Estações do Ano , Estudos Transversais , México/epidemiologia , Organização Mundial da Saúde , Centers for Disease Control and Prevention, U.S.RESUMO
Introduction: Seasonal influenza is a contagious viral respiratory condition typically occurring in the fall to early spring months of the year globally. The risk of infection from seasonal influenza can be greatly reduced with vaccination. Unfortunately, research has indicated that the seasonal influenza vaccination rate in Saudi Arabia is low. This study assessed the uptake of seasonal influenza vaccination among adults residing in Al-Jouf region, Saudi Arabia. Materials and Methods: A cross-sectional survey targeting adults (20-80 years) residing in Al-Jouf region, Saudi Arabia, was conducted to gather information about their sociodemographic characteristics, chronic conditions, knowledge about periodic health examinations (PHE), regular use of PHE, and uptake of seasonal influenza vaccination. Comparative statistics and a multivariate logistic regression analysis were conducted to determine characteristics associated with the uptake of seasonal influenza vaccination. Results: A total of 624 respondents completed the survey and participated in this study. Among the participants, 27.4% indicated they visited their primary healthcare centers or hospitals every year to get a seasonal influenza vaccination. The regression analysis showed that the odds of getting a seasonal influenza vaccination were higher among employed respondents (Odds Ratio [OR] = 1.73; P = 0.039), respondents who were employees of the healthcare sector (OR = 2.31; P = 0.001), and those with a higher PHE Knowledge Score (OR = 1.22; P = 0.008), compared to their counterparts. Conclusions: Seasonal influenza is a serious condition warranting appropriate prevention measures, including vaccination. However, this study confirmed low rates of seasonal influenza vaccination in Al-Jouf Region of Saudi Arabia. Interventions to boost vaccination uptake, in particular among unemployed individuals, those not working in the healthcare sector, and those with lower PHE knowledge Scores, are therefore recommended.
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BACKGROUND: The significant annual burden caused by seasonal influenza has led to global calls for increased influenza vaccination coverage rates (VCRs). We aimed to estimate the proportion of the German population at high risk of serious illness from influenza due to chronic conditions and to estimate age-specific VCRs of people with/without chronic conditions. METHODS: Using health insurance claims data covering nine influenza seasons (2010-2019), we assessed up to 7 million insured individuals per season across all German regions. Individuals were classified according to age and presence of chronic health conditions. VCRs were estimated using outpatient healthcare utilization documentation. RESULTS: In the 2018-2019 influenza season, 47.3% of individuals had ≥1 chronic condition. Most common were circulatory disorders, accounting for more than a third of individuals with ≥1 condition. Prevalence of chronic diseases, and therefore the proportion of high-risk individuals, increased slightly over time across most age groups. A downward trend in influenza VCRs was observed in all age groups until the 2017-2018 season, followed by a noticeable increase in the 2018-2019 season. Highest VCRs occurred among individuals of ≥60 years, with a 38.5% VCR for this age group in the 2018-2019 season. Several factors, including age, chronic condition type, and geographical location, affected VCRs. CONCLUSIONS: Influenza VCRs in individuals at high risk of severe complications from influenza infection are insufficient. Our results suggest that intensified public health efforts are necessary to reach the World Health Organization vaccination coverage target of 75%.
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Vacinas contra Influenza , Influenza Humana , Humanos , Cobertura Vacinal , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Prevalência , Vacinação , Alemanha/epidemiologia , Doença Crônica , Estações do Ano , Seguro Saúde , Análise de DadosRESUMO
Objective@#To describe the clinical features, causal agent and transmission mode of a fever outbreak in a school in Shanghai.@*Methods@#Field epidemiological approaches including case definition development, searching for contacts, distribution of diseases description, environmental sampling and laboratory testing.@*Results@#A total of 16 influenza like cases were included, all concentrated in the one class of grade two, including 15 students and 1 teacher. Among student cases, the incidence rate was 36.59% (15/41), the average age was 7.4 years, the incidence rate was 36.84%(7/19) for boys, 36.36%(8/22) for girls. The clinical course was 5-15 days, with the median of 9 days, and 18.75%(3/16) of the cases stayed studying while sick. The nasopharyngeal swab specimens in 16 cases all tested positive for influenza B, of which 11 tested positive for mycoplasma pneumoniae and 1 case also tested positive for coronavirus OC43. Body temperature, number of mononuclear cells, and treatment time of patients infected with Influenza B and mycoplasma pneumoniae were higher than those of patients infected with influenza B alone( P <0.05). The outbreak lasted for 12 days, all sick students were treated and discharged from hospital, with no severe cases or death, and the outbreak was effectively controlled.@*Conclusion@#This campus cluster outbreak caused by influenza B and mycoplasma pneumoniae. Patients with influenza B with mycoplasma pneumoniae have severe symptoms and a long course of illness, suggesting the importance of early management of the epidemic.
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Objective@#To investigate the epidemiological data of an outbreak of influenza A in a primary school in Shanghai, to provide reference for targeted prevention and control measures.@*Methods@#A field epidemiological method was used to investigate and collect the data of influenza A outbreak in a primary school in Jing an District from November 8 to December 6, 2022, through on site follow up and telephone return visit to health teachers and cases. The distribution characteristics of the epidemic were analyzed by descriptive epidemiology.@*Results@#The first case developed symptoms of cough, sore throat, and fever on the morning of November 8th 2022, with a maximum body temperature of 38.6 ℃. Later, the clinical diagnosis was influenza A. The total number of influenza like cases reported in this outbreak is 99, including 92 students and 7 teachers. The total incidence rate was 9.45%. The clinical symptoms of all cases were fever, sore throat, and cough; 27 cases of influenza A were diagnosed by hospital rapid diagnostic reagents. The second grade students had the highest case incidence rate(24.46%), and there was a statistically significant difference in case incidence rates among students of different grades ( χ 2=48.28, P <0.01). The case incidence rate on the second floor was the highest (23.47%), and there was a statistically significant difference between the case incidence rates on different floors ( χ 2=52.38, P < 0.01 ). Etiological testing showed that the influenza virus causing this outbreak was type A H3N2 virus.@*Conclusion@#This outbreak is a campus cluster outbreak caused by influenza A (H3N2) virus. The health and education departments should strengthen cooperation to effectively implement prevention and control measures of infectious diseases, and timely identify the source of infection and cut off the transmission route.
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Influenza is a common disease that affects the population in many ways.When the elderly contract influenza, they are prone to complications, leading to severe illness and even death.Influenza has serious consequences to the health of older people.Identification and prevention of influenza in the elderly are of critical importance.This paper summarizes certain distinctive features of influenza in the elderly.
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Abstract Placebo use in clinical trials, whenever a proven effective treatment exists, is one of the most debated topics in contemporary research ethics. This article addresses the ethical framework for placebo use in clinical trials assessing vaccine efficacy in pregnant women. Vaccine trial participants are healthy at the outset and some must be infected during the study to demonstrate the product's efficacy, meaning that placebo-treated participants are under risk of serious and irreversible harm. If effective vaccines exist, such risk precludes placebo use. This interdiction should be extended to any clinical trial of vaccine efficacy in pregnant women, because a demonstration of clinical efficacy in nonpregnant individuals and comparable immunogenic responses in pregnant women are predictors of efficacy in pregnancy as well. Moreover, product effectiveness in real-world use scenarios can be ascertained by observational studies conducted after its inclusion in vaccination campaigns.
Resumen El uso de placebo en ensayos clínicos es uno de los principales temas debatidos sobre la ética en investigación contemporánea cuando existe un tratamiento eficaz probado. Este artículo aborda la ética en el uso de placebo en ensayos clínicos sobre la eficacia de vacuna en mujeres embarazadas. Las participantes en los ensayos de vacunas estaban sanas al inicio del estudio, y algunas fueron vacunadas durante el estudio para demostrar la eficacia del producto. Las participantes tratadas con placebo corren el riesgo de sufrir daños graves e irreversibles. Si existen vacunas efectivas, este riesgo impide el uso de placebo. Este impedimento debe extenderse a cualquier ensayo clínico de eficacia de vacuna en embarazadas, pues la eficacia clínica demostrada en mujeres no embarazadas y las respuestas inmunogénicas comparables con las embarazadas son predictores de eficacia en el embarazo. Además, la efectividad del producto se constata en estudios observacionales realizados tras las campañas de vacunación.
Resumo O uso de placebo em ensaios clínicos, quando um tratamento comprovadamente eficaz existe, é um dos principais tópicos debatidos na ética em pesquisa contemporânea. Este artigo aborda o quadro ético para o uso de placebo em ensaios clínicos que avaliam a eficácia de vacina em gestantes. Participantes em ensaios de vacina são saudáveis no início e alguns devem ser inoculados durante o estudo para demonstrar a eficácia do produto. Ou seja, participantes tratados com placebo estão sob risco de danos graves e irreversíveis. Se existirem vacinas eficazes, esse risco impede o uso de placebo. Essa interdição deve ser estendida a qualquer ensaio clínico de eficácia de vacina em gestantes, pois a demonstração de eficácia clínica em não gestantes e as respostas imunogênicas comparáveis em gestantes também são preditoras de eficácia na gravidez. Ademais, a eficácia do produto em cenários reais de uso pode ser verificada por estudos observacionais realizados após sua inclusão em campanhas de vacinação.
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Bioética , Influenza Humana , Equipolência Terapêutica , COVID-19RESUMO
Annual seasonal influenza vaccination is recommended for individuals at high risk of developing post-infection complications in many locations. However, reduced vaccine immunogenicity and effectiveness have been observed among repeat vaccinees in some influenza seasons. We investigated the impact of repeated influenza vaccination on relative vaccine effectiveness (VE) among individuals who were recommended for influenza vaccination in the United Kingdom with a retrospective cohort study using primary healthcare data from the Clinical Practice Research Datalink, a primary care database in the United Kingdom. Relative VE was estimated against general practitioner-diagnosed influenza-like illnesses (GP-ILI) and medically attended acute respiratory illnesses (MAARI) among participants who have been repeatedly vaccinated compared with first-time vaccinees using proportional hazards models. Relative VE against MAARI may be reduced for individuals above 65 years old who were vaccinated in the current and previous influenza seasons for some influenza seasons. However, these findings were not conclusive as we could not exclude the possibility of residual confounding in our dataset. The use of routinely collected data from electronic health records to examine the effects of repeated vaccination needs to be complemented with sufficient efforts to include negative control outcomes to rule out residual confounding.
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Vacinas contra Influenza , Influenza Humana , Adulto , Humanos , Idoso , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Estudos Retrospectivos , Eficácia de Vacinas , Vacinação , Reino Unido/epidemiologiaRESUMO
BACKGROUND: Antibiotics are frequently prescribed during viral respiratory infection episodes in primary care. There is limited information about antibiotic prescription during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in primary care and its association with risk factors for an adverse course. AIM: To compare the proportion of antibiotic prescriptions between patients with COVID-19 and influenza or influenza-like symptoms, and to assess the association between antibiotic prescriptions and risk factors for an adverse course of COVID-19. DESIGN & SETTING: An observational cohort study using pseudonymised and coded routine healthcare data extracted from 85 primary care practices in the Netherlands. METHOD: Adult patients with influenza and influenza-like symptoms were included from the 2017 influenza season to the 2020 season. Adult patients with suspected or confirmed COVID-19 were included from the first (15 February 2020-1 August 2020) and second (1 August 2020-1 January 2021) SARS-CoV-2 waves. Proportions of antibiotic prescriptions were calculated for influenza and COVID-19 patients. Odds ratios (ORs) were used to compare the associations of antibiotic prescriptions in COVID-19 patients with risk factors, hospital admission, intensive care unit (ICU) admission, and mortality. RESULTS: The proportion of antibiotic prescriptions during the first SARS-CoV-2 wave was lower than during the 2020 influenza season (9.6% versus 20.7%), difference 11.1% (95% confidence interval [CI] = 8.7 to 13.5). During the second SARS-CoV-2 wave, antibiotic prescriptions were associated with being aged ≥70 years (OR 2.05; 95% CI = 1.43 to 2.93), the number of comorbidities (OR 1.46; 95% CI = 1.18 to 1.82), and admission to hospital (OR 3.19; 95% CI = 2.02 to 5.03) or ICU (OR 4.64; 95% CI = 2.02 to 10.62). CONCLUSION: Antibiotic prescription was less common during the SARS-CoV-2 pandemic than during influenza seasons, and was associated with an adverse course and its risk factors. The findings suggest a relatively targeted prescription policy of antibiotics in primary care during COVID-19.