The burden of seasonal and pandemic influenza in infants and children

The economic rationale for cell-based influenza vaccines in children and adults: A review of cost-effectiveness analyses

Seasonal influenza significantly affects both health and economic costs in children and adults. This narrative review summarizes published cost-effectiveness analyses (CEAs) of cell-based influenza vaccines in children and adults <65 years of age, critically assesses the assumptions and approaches used in these analyses, and considers the role of cell-based influenza vaccines for children and adults. CEAs from multiple countries demonstrated the cost-effectiveness of cell-based quadrivalent influenza vaccines (QIVc) compared with egg-based trivalent/quadrivalent influenza vaccines (TIVe/QIVe). CEA findings were consistent across models relying on different relative vaccine effectiveness (rVE) estimate inputs, with the rVE of QIVc versus QIVe ranging from 8.1% to 36.2% in favor of QIVc. Across multiple scenarios and types of analyses, QIVc was consistently cost-effective compared with QIVe, including in children and adults across different regions of the world.

Effectiveness of cocoon strategy vaccination on prevention of influenza-like illness in young infants

During the initial half-year of their existence, infants cannot receive the influenza vaccine, yet they face the greatest susceptibility to severe influenza complications. In this study, we seek to determine whether influenza vaccination of maternal and household contacts is associated with a reduced risk of influenza-like illness (ILI) and severe acute respiratory infection (SARI) in infants. This work was prospectively conducted during the influenza season. A total of 206 infants were included in this study. The percentage of infants with only the mother vaccinated is 12.6% (n:26), and the percent of infants with all household contacts vaccinated is 16% (n:33). Among the infants with only the mother vaccinated, the effectiveness of influenza vaccine is estimated as 35.3% for ILI and 41.3% for SARI. Among infants with all household contacts vaccinated, the effectiveness is estimated as 48.9% for ILI and 76.9% for SARI. Based on the results of multivariate logistic regression analysis, all-household vaccination is a protective factor against SARI (OR: 0.07 95% CI [0.01-0.56]), household size (OR: 1.75, 95% CI [1.24-2.48]) and presence of secondhand smoke (OR: 2.2, 95% CI [1.12-4.45]) significant risk factors for SARI in infants. The mother alone being vaccinated is not a statistically significant protective factor against ILI (OR: 0.46, 95% CI [0.19-1.18]) or SARI (OR: 0.3, 95% CI [0.11-1.21]). Along with the obtained results and analysis, this study provides clear evidence that influenza vaccination of all household contacts of infants aged 0-6 months is significantly associated with protecting infants from both ILI and SARI.

Parents and teachers' perspectives on a school-located influenza vaccination program: A pilot study in the Region of Murcia, Spain

During the 2022-2023 season, the Region of Murcia (an autonomous community of Spain) introduced the influenza vaccination campaign in children aged 24-59 months with the live-attenuated influenza nasal spray vaccine. To expand coverage, a pilot study was conducted to include the 3- to 4-year population in 24 public schools. The aim of the study was to assess the experiences of parents and teachers involved in the project. This was a psychosocial qualitative study in which information was collected from a cohort of 23 parents and 17 teachers who attended three and two focus group sessions, respectively. A high degree of satisfaction with the school-located influenza vaccination program was consistently reported. The teachers reported creating a friendly environment and acting as companions to support children in the absence of their parents. They also considered the intranasal route, which avoids intramuscular puncture, as a facilitating element that turned the vaccination process into a kind of game. Parents emphasized the importance of vaccination to protect their children, and secondarily, to ensure protection of the family nucleus. Some parents who had their children already vaccinated in the health care center reported preference for the school setting, probably selecting this option in the future. The availability of school-based influenza vaccination promoted greater equity in accessing the vaccine and facilitated family reconciliation. To optimize coverage and minimize potential reluctance, providing the necessary information to parents both before and after vaccination was considered. School-located influenza vaccination was feasible and is a valuable strategy to be implemented in future campaigns.

Sequential early-life viral infections modulate the microbiota and adaptive immune responses to systemic and mucosal vaccination

Increasing evidence points to the microbial exposome as a critical factor in maturing and shaping the host immune system, thereby influencing responses to immune challenges such as infections or vaccines. To investigate the effect of early-life viral exposures on immune development and vaccine responses, we inoculated mice with six distinct viral pathogens in sequence beginning in the neonatal period, and then evaluated their immune signatures before and after intramuscular or intranasal vaccination against SARS-CoV-2. Sequential viral infection drove profound changes in all aspects of the immune system, including increasing circulating leukocytes, altering innate and adaptive immune cell lineages in tissues, and markedly influencing serum cytokine and total antibody levels. Beyond changes in the immune responses, these exposures also modulated the composition of the endogenous intestinal microbiota. Although sequentially-infected mice exhibited increased systemic immune activation and T cell responses after intramuscular and intranasal SARS-CoV-2 immunization, we observed decreased vaccine-induced antibody responses in these animals. These results suggest that early-life viral exposures are sufficient to diminish antibody responses to vaccination in mice, and highlight the potential importance of considering prior microbial exposures when investigating vaccine responses.

Safety, reactogenicity and immunogenicity of an intranasal seasonal influenza vaccine adjuvanted with gram-positive matrix (GEM) particles (FluGEM): A randomized, double-blind, controlled, ascending dose study in healthy adults and elderly

BACKGROUND

Intranasal administration of respiratory vaccines offers many advantages such as eliciting both systemic and mucosal immunity at the point of viral entry. Immunogenicity of intranasal vaccination can be improved through the use of adjuvants. Bacteria-like particles derived fromLactococcus lactishave the potential to serve as a vaccine adjuvant.This clinical study investigated the safety, reactogenicity and immunogenicity of intranasal seasonal influenza vaccine adjuvanted with gram-positive matrix particles (FluGEM®).

METHODS

This was a first-in-human, randomized, double-blind, controlled, dose-escalation study performed at the Centre for Human Drug Research (CHDR), the Netherlands. Participants aged 18-49 were randomized in a 3:1 ratio to receive FluGem® in ascending doses (two-dose regimens) together with a standard trivalent inactivated influenza vaccine or unadjuvanted TIV only. Primary outcomes were safety and tolerability. Secondary outcomes were serum hemagglutination inhibition (HI) antibody titers and mucosal IgA. The most immunogenic dose was used in an additionalelderly cohort (>65 years).

RESULTS

Ninty participants were included. Intranasal FluGem®was safe and well tolerated. The majority of adverse events were mild (97.4 %) with (un)solicited adverse events comparable across all dose levels and control groups. All groups showed geometric mean increases ≥ 2.5-fold. Seroconversion (≥40 % participants) was achieved at both day 21 (single-dose) and 42 (two-dose) for the 1.25 mg dose and on day 42 (two-dose only) for the 2.5 mg dose. Highest geometric mean IgA increases were observed in the 1.25 mg group on day 21. Immunogenicity was less pronounced in elderly.

CONCLUSIONS

Intranasal vaccination of FluGEM®was safe and tolerable in healthy adult volunteers aged 18-49 years and 65 and older. Highest immunogenicity was observed for 1.25 mg and 2.5 mg doses (compared to 5 mg) suggesting a potential non-linear dose-response relationship.More research is needed to further investigate the capabilities of bacteria-like peptides as adjuvants.

The role of influenza Hemagglutination-Inhibition antibody as a vaccine mediator in children

BACKGROUND

Influenza vaccination may protect through the humoral immune response, cellular immune response, or possibly both. Immunity after vaccination can be mediated through antibodies that may be detected by the rise of serum hemagglutination inhibition (HAI) titers. Our objective was to investigate the proportion of protection against influenza mediated through antibodies by measuring the rise of HAI titer (indirect effect) compared to that induced through other immune mechanisms (direct effect) for influenza A and B.

METHODS

We analysed data from a cluster randomized trial conducted during the 2008-2009 season in which Canadian Hutterite children were vaccinated against influenza. We used inverse probability weighting to calculate the indirect and direct effect of vaccination against influenza A/H3N2 and influenza B/Brisbane using HAI titres and overall vaccine efficacy.

RESULTS

We included data on 617 children from 46 Hutterite colonies, aged between 3 and 15 years who were vaccinated with either inactivated trivalent influenza vaccine or hepatitis A vaccine. Vaccine efficacy was 63 % for influenza A (H3N2) and 28 % for influenza B. The hazard ratio for protection against influenza A/H3N2 due to an indirect effect of vaccination was 0.96 (95 % confidence interval (CI) of 0.00 to 2.89) while for the direct effect it was 0.38 (95 % CI of 0.00 to 5.47). The hazard ratio for influenza B indirect effect was 0.75 (95 % CI of 0.07 to 1) and for the direct effect 0.96 (95 % CI of 0.00 to 12.02). In contrast, repeating the analysis using microneutralization in a subgroup of 488 children revealed that the protective effect for vaccination for A/H3N2 was entirely mediated by antibodies but only for 13 % for influenza B.

CONCLUSIONS

Although vaccination provided higher protective effectiveness against influenza A than B, most of the influenza A vaccine efficacy likely occurred through antibodies other than what could be detected by HAI titres. In contrast, for influenza B, while the HAI titres appeared to mediate most of the vaccine effectiveness, this was not confirmed by microneutralization analysis.

Pediatric practice experiences with second dose influenza vaccination: An AAP Pediatric Research in Office Settings (PROS) Study

OBJECTIVES

Explore pediatric staff experiences administering the second influenza vaccine dose.

STUDY DESIGN

Qualitative focus groups/interviews.

METHODS

As part of the National Institutes of Health-funded Flu2Text randomized control trial of text message reminders for second influenza vaccine dose, we conducted seven focus groups and four individual interviews (n = 39 participants total) with clinicians and staff from participating practices from the American Academy of Pediatrics' Pediatric Research in Office Settings (PROS) Network. Of 37 participating practices, 10 were selected through stratified sampling of practices with highest (n = 5) and lowest (n = 5) randomized controlled trial effect sizes. A semi-structured discussion guide included questions that addressed parental, practice, and health system barriers/facilitators to second influenza vaccine dose administration. Using the Systems Model of Clinical Preventive Care as a conceptual framework, two investigators independently coded transcripts (Κ = 0.86, high agreement) with NVivo 12 Plus. Coding inconsistencies were resolved by consensus.

RESULTS

Clinicians/staff reported that administering the second influenza vaccine dose in a season was more complex than other childhood vaccines. They highlighted parental uncertainty about the need for the second dose and the difficulty and inconvenience of bringing children back to the office as important barriers. Caregiver-staff relationships were perceived as helpful in getting children vaccinated with their second dose and vaccine reminders were seen as important cues-to-action.

CONCLUSIONS

Ensuring receipt of two doses of the influenza vaccine in a given season presents unique challenges. Themes identified provide a framework for understanding opportunities to bolster second dose receipt, including explaining why two doses are needed, offering flexible hours for vaccination, and sending vaccine reminders.

Surveillance of respiratory viruses by aerosol screening in indoor air as an early warning system for epidemics

The development of effective methods for the surveillance of seasonal respiratory viruses is required for the timely management of outbreaks. We aimed to survey Influenza-A, Influenza-B, RSV-A, Rhinovirus and SARS-CoV-2 surveillance in a tertiary hospital and a campus over 5 months. The effectiveness of air screening as an early warning system for respiratory viruses was evaluated in correlation with respiratory tract panel test results. The overall viral positivity was higher on the campus than in the hospital (55.0% vs. 38.0%). Influenza A was the most prevalent pathogen in both locations. There were two influenza peaks (42nd and 49th weeks) in the hospital air, and a delayed peak was detected on campus in the 1st-week of January. Panel tests indicated a high rate of Influenza A in late December. RSV-A-positivity was higher on the campus than the hospital (21.6% vs. 7.4%). Moreover, we detected two RSV-A peaks in the campus air (48th and 51st weeks) but only one peak in the hospital and panel tests (week 49). Although rhinovirus was the most common pathogen in panel tests, rhinovirus positivity was low in air samples. The air screening for Influenza-B and SARS-Cov-2 revealed comparable positivity rates with panel tests. Air screening can be integrated into surveillance programs to support infection control programs for potential epidemics of respiratory virus infections except for rhinoviruses.

Safety and effectiveness of baloxavir marboxil and oseltamivir for influenza in children: a real-world retrospective study in China

Objectives

To evaluate the safety and effectiveness of baloxavir marboxil (baloxavir) and oseltamivir in pediatric influenza patients in China.

Methods

Patients filling a prescription for baloxavir or oseltamivir within 48 h following an influenza-related outpatient visit were identified in Children's Hospital of Fudan University in China between March 2023 and December 2023. Outcomes were assessed after antiviral treatment and included the incidence of adverse reactions and the duration of fever and other flu symptoms.

Results

A total of 1430 patients infected with influenza A were collected and 865 patients (baloxavir: n = 420; oseltamivir: n = 445) finally included. The incidence of adverse reactions of nausea and vomiting was significantly different between the baloxavir group (2.38%) and the oseltamivir group (12.13%) [P < 0.001, OR = 4.2526, 95%CI (2.0549, 9.6080)]. No differences in other adverse reactions were observed between the two groups. The mean duration of fever in baloxavir group (1.43d) was significantly shorter than that in oseltamivir group (2.31d) [P < 0.001, 95%CI (0.7815, 0.9917)]. There were no differences in the mean duration of nasal congestion and runny nose, sore throat, cough, and muscle soreness between two groups.

Conclusions

The incidence of nausea and vomiting is lower with baloxavir compared to oseltamivir, and the duration for complete fever reduction is shorter with baloxavir than with oseltamivir. The results indicate that baloxavir is well tolerated and effective in Chinese children.

Neurological involvement related to the influenza virus in children: A 5-year single-centre retrospective study

INTRODUCTION

Inflammation related to influenza virus infection can lead to multiple neurological presentations. Encephalitis is one of them, mostly accompanied by seizures, with different profiles depending on the epidemics and previous medical conditions.

MATERIALS AND METHODS

All children presenting neurological symptoms and positive for influenza virus RNA detection in a respiratory sample between November 2018 and April 2023, hospitalized in the Department of Paediatric Neurology of Toulouse Children's Hospital, were retrospectively analysed.

RESULTS

Among the 1,277 children diagnosed with influenza in our centre, 131 (10.3 %) were hospitalized for neurological features. The year 2020-2021 was marked by zero incidence of positive influenza tests, associated with the COVID-19 pandemic. Among the 131 patients included, 71.6 % were under 5 years old. Most of them (80.9 %) were infected by influenza A virus. The first neurological symptoms were mainly seizures in 73.3 % of patients. Possible or confirmed encephalitis was observed in 29 % of cases, including one acute necrotizing encephalopathy. Few children (6.1 %) presented with acute myositis. Twenty-seven patients (20.6 %) had a personal history of significant previous neurological disorders. Most patients (88.5 %) displayed a rapid favourable outcome, marked by the disappearance of their neurological symptoms within the first 2 days. Anti-epileptic drugs were introduced in 1.5 % of cases, and adapted in 16.8 %, mainly in patients with febrile status epilepticus and an abnormal EEG.

CONCLUSION

Neurological features were frequently associated with influenza infection in children; most were transient. Effects on long-term neurodevelopmental outcomes need to be clarified as our follow-up was limited, especially in children with pre-existing neurological conditions.

The Hospital Burden of Flu in Italy: a retrospective study on administrative data from season 2014-2015 to 2018-2019

BACKGROUND

Every year in Italy, influenza affects about 4 million people. Almost 5% of them are hospitalised. During peak illness, enormous pressure is placed on healthcare and economic systems. This study aims to quantify the clinical and economic burden of severe influenza during 5 epidemic seasons (2014-2019) from administrative claims data.

METHODS

Patients hospitalized with a diagnosis of influenza between October 2014, and April 2019, were analyzed. Clinical characteristics and administrative information were retrieved from health-related Administrative Databases (ADs) of 4 Italian Local Health Units (LHUs). The date of first admission was set as the Index Date (ID). A follow-up period of six months after ID was considered to account for complications and re-hospitalizations, while a lookback period (2 years before ID) was set to assess the prevalence of underlying comorbidities.

RESULTS

Out of 2,333 patients with severe influenza, 44.1% were adults ≥ 65, and 25.6% young individuals aged 0-17. 46.8% had comorbidities (i.e., were at risk), mainly cardiovascular and metabolic diseases (45.3%), and chronic conditions (24.7%). The highest hospitalization rates were among the elderly (≥ 75) and the young individuals (0-17), and were 37.6 and 19.5/100,000 inhabitants/year, respectively. The average hospital stay was 8 days (IQR: 14 - 4). It was higher for older individuals (≥ 65 years, 11 days, [17 - 6]) and for those with comorbidities (9 days, [16 - 6]), p-value < 0.001. Similarly, mortality was higher in elderly and those at risk (p-value < 0.001). Respiratory complications occurred in 12.7% of patients, and cardiovascular disorders in 5.9%. Total influenza-related costs were €9.7 million with hospitalization accounting for 95% of them. 47.3% of hospitalization costs were associated with individuals ≥ 65 and 52.9% with patients at risk. The average hospitalisation cost per patient was € 4,007.

CONCLUSIONS

This retrospective study showed that during the 2014-2019 influenza seasons in Italy, individuals of extreme ages and those with pre-existing medical conditions, were more likely to be hospitalized with severe influenza. Together with complications and ageing, they worsen patient's outcome and may lead to a prolonged hospitalization, thus increasing healthcare utilization and costs. Our data generate real-world evidence on the burden of influenza, useful to inform public health decision-making.

The Attitudes of Healthcare Professionals in an Autonomous Community in Spain towards Paediatric Influenza Vaccination

In the 2022-2023 influenza season, three autonomous communities anticipated the document approved by the Public Health Commission recommending influenza vaccination for all children aged 6 to 59 months. The primary objective of this study was to evaluate the attitude of healthcare professionals towards the first universal vaccination campaign in our region, as well as the acceptability of the vaccines used and their attitude towards pilot school vaccination. This was a cross-sectional, survey-based, descriptive study. All healthcare professionals involved in the campaign were invited to participate. Overall, 91.9% of surveyed professionals thought that influenza vaccination from 6 to 59 months was important or very important, and 89.8% had previous experience regarding the intramuscular vaccine. Healthcare professionals rated the intranasal vaccine significantly more positively, but there were no differences when asking about each vaccine without comparison. The inhaled vaccine was preferred by 97.5% for the following campaign. Pilot school vaccination had a 75% acceptance rate. The inhaled vaccine was preferred by most professionals, and pilot school vaccination was highly accepted and independently associated with the importance of vaccination as considered by physicians, being a medical doctor, and participation in the pilot programme.

Effect of maternal vaccination on infant morbidity in Bangladesh

BACKGROUND

Risk factors of infant mortality in Africa and south Asian countries have been broadly discussed. However, infant morbidity is largely underestimated. We analyzed the data from a randomized vaccine trial in Bangladesh to identify and assess the effect of risk factors on infant morbidity.

METHODS

Pregnant women were randomly assigned to receive either inactivated influenza vaccine or pneumococcal polysaccharide vaccine and the infants were randomly assigned to receive 7-valent pneumococcal conjugate vaccine or Hib conjugate vaccine at week 6, 10 and 14. The data were collected from August 2004 through December 2005. Each pair of infant and mother were followed for 24 weeks after birth with weekly visits. Generalized estimating equations (GEE) for repeated measurements and Poisson regression models were used to identify the risk factors and evaluate their effect on the longitudinal incidence and total number of episodes of respiratory illness with fever (RIF), diarrhea disease, ear problem and pneumonia.

RESULTS

A total of 340 pregnant women were randomized with mean age of 25 years. The baseline mother and infant characteristics were similar between two treatment groups. Exclusive breastfeeding and higher paternal education level were common factors associated with lower infant morbidity of RIF (adjusted OR = 0.40 and 0.94 with p < 0.01 and p = 0.02, respectively), diarrhea disease (adjusted OR = 0.39 and 0.95 with p < 0.01 and p = 0.04, respectively), and ear problem (adjusted OR = 0.20 and 0.76 with p < 0.01 and p < 0.01, respectively). Maternal influenza vaccine significantly reduced the incidence of RIF (adjusted OR = 0.54; p < 0.01) but not diarrhea disease or ear problem (p > 0.05). Female infants had lower incidence of diarrhea disease (adjusted OR = 0.67; p = 0.01) and ear problem (adjusted OR = 0.12; p = 0.01).

CONCLUSIONS

Maternal influenza vaccination, exclusive breastfeeding, female children, and higher paternal education level significantly reduced the infant morbidity within the 24 weeks after birth in Bangladesh.

Impact of health education on promoting influenza vaccination health literacy in primary school students: a cluster randomised controlled trial protocol

INTRODUCTION

Influenza is a major public health threat, and vaccination is the most effective prevention method. However, vaccination coverage remains suboptimal. Low health literacy regarding influenza vaccination may contribute to vaccine hesitancy. This study aims to evaluate the effect of health education interventions on influenza vaccination rates and health literacy.

METHODS AND ANALYSIS

This cluster randomised controlled trial will enrol 3036 students in grades 4-5 from 20 primary schools in Dongguan City, China. Schools will be randomised to an intervention group receiving influenza vaccination health education or a control group receiving routine health education. The primary outcome is the influenza vaccination rate. Secondary outcomes include health literacy levels, influenza diagnosis rate, influenza-like illness incidence and vaccine protection rate. Data will be collected through questionnaires, influenza surveillance and self-reports at baseline and study conclusion.

ETHICS AND DISSEMINATION

Ethical approval has been sought from the Ethics Committee of the School of Public Health, Sun Yat-sen University. Findings from the study will be made accessible to both peer-reviewed journals and key stakeholders.

TRIAL REGISTRATION NUMBER

NCT06048406.

Analysis of clinical characteristics and risk factors for death due to severe influenza in children

OBJECTIVE

The study analyzed the clinical features of children who had severe influenza and discussed on the risk factors associated with death in this population.

METHODS

A total of 167 children with severe influenza admitted to the intensive care unit of our hospital from January 2018 to August 2023 were selected and divided into the death group (27 cases) and the survival group (140 cases). Demographic characteristics and clinical data were collected and compared between the two groups. Logistic regression analysis was used to explore the risk factors for death in children with severe influenza.

RESULTS

The male-to-female ratio of the 167 children with severe influenza was 2.21:1, the median age was 3 years, and influenza A accounted for 70.66%. The CD4+ T cells percentage and CD4/CD8 were lower in the death group; the percentage of comorbid underlying diseases, mechanical ventilation, other systemic involvement, comorbid associated encephalopathy or encephalitis, and red blood cell distribution width (RDW), lactate dehydrogenase, activated partial thromboplastin time (APTT), and interleukin 6 were higher in the death group. The mechanical ventilation, associated encephalopathy or encephalitis, RDW, APTT, and CD4/CD8 were the independent risk factors for death.

CONCLUSION

Mechanical ventilation, comorbid encephalopathy or encephalitis, increased RDW, prolonged APTT, and decreased CD4/CD8 are independent risk factors for death in children with severe influenza.

Variation in the basal immune state and implications for disease

Analysis of pre-existing immunity and its effects on acute infection often focus on memory responses associated with a prior infectious exposure. However, memory responses occur in the context of the overall immune state and leukocytes must interact with their microenvironment and other immune cells. Thus, it is important to also consider non-antigen-specific factors which shape the composite basal state and functional capacity of the immune system, termed here as I0 ('I naught'). In this review, we discuss the determinants of I0. Utilizing influenza virus as a model, we then consider the effect of I0 on susceptibility to infection and disease severity. Lastly, we outline a mathematical framework and demonstrate how researchers can build and tailor models to specific needs. Understanding how diverse factors uniquely and collectively impact immune competence will provide valuable insights into mechanisms of immune variation, aid in screening for high-risk populations, and promote the development of broadly applicable prophylactic and therapeutic treatments.

Platelet distribution width as an useful indicator of influenza severity in children

PURPOSE

The present study aims to investigate the potential of platelet distribution width as an useful parameter to assess the severity of influenza in children.

METHODS

Baseline characteristics and laboratory results were collected and analyzed. Receiver operating characteristic (ROC) curve analysis was used to joint detection of inflammatory markers for influenza positive children, and the scatter-dot plots were used to compare the differences between severe and non-severe group.

RESULTS

Influenza B positive children had more bronchitis and pneumonia (P < 0.05), influenza A infected children had more other serious symptoms (P = 0.007). Neutrophil count, lymphocyte count, neutrophil-to-lymphocyte ratio (NLR), and platelet parameters performed differently among < 4 years and ≥ 4 years children with influenza. Combined detection of platelet parameters and other indicators could better separate healthy children from influenza infected children than single indicator detection. The levels of platelet distribution width of children with severe influenza (A and B) infection was significantly dropped, compared with non-severe group (P < 0.05).

CONCLUSIONS

Platelet distribution width could be a very useful and economic indicator in distinction and severity assessment for children with influenza.

Epidemiology and Burden of Influenza in Children 0-14 Years Over Ten Consecutive Seasons in Italy

BACKGROUND

In Europe, influenza vaccination coverage in the pediatric population is low. This study describes the influenza incidence and associated healthcare utilization in the pediatric population in Italy.

METHODS

Deidentified data from electronic medical records for children 0-14 years old seen by >150 family pediatricians in the Pedianet network in Italy were evaluated for 10 influenza seasons spanning 2010-2020. Incidence of influenza (cases per 1000 person-months), related sequelae and associated healthcare resource use were determined using diagnostic, prescription and medical examination data.

RESULTS

Over 10 seasons, an average of 8892 influenza cases (range, 4700-12,419; total 88,921) were diagnosed in a cohort of 1,432,384 children 0-14 years of age. Influenza vaccination coverage was 3.6% among children with an influenza diagnosis and 6.8% among children without. Influenza-related healthcare resource utilization included 1.58 family pediatrician visits per influenza episode and 220 ED and 111 hospital admissions, with the highest resource usage among children 1-4 years and lowest among children <6 months old. The most common influenza complications were acute otitis media (2.9% of influenza cases) and pneumonia (0.5%). Antibiotics were prescribed in 38.7% of influenza cases; no antiviral agents were prescribed. One intensive care unit admission and 2 cases requiring ventilatory support were documented. No influenza-related deaths were reported.

CONCLUSION

Pediatric influenza vaccination was low despite the burden and healthcare use related to seasonal influenza in the pediatric population during a 10-year period in Italy.

The protective effect of 999 XiaoErGanMao granules on the lungs and intestines of influenza A virus-infected mice

CONTEXT

Gastrointestinal symptoms are a common complication of influenza virus infection in children, which the gut-lung axis become involved in its biological progress. The protective effect of 999 XiaoErGanMao granules (XEGMG) on multi-organ injury in viral pneumonia remains unclear.

OBJECTIVE

To investigate the therapeutic effect of XEGMG on lungs and intestines injury in A/FM/1/47 (H1N1) influenza virus-infected mice.

MATERIALS AND METHODS

Male BALB/c mice were infected with the 2LD₅₀ H1N1 influenza virus and then treated with XEGMG (6 or 12 g/kg) intragastrically once a day for 4 days. The lung and colon samples were then collected for pathological observation, and assays for inflammatory cytokines and intestinal barrier. Mouse feces were collected to evaluate the intestinal microbiota.

RESULTS

Treating with XEGMG (12 g/kg) can mitigate body weight loss caused by 2LD₅₀ H1N1 infection. It can also reduce lung index and pathological damage with the decreased inflammatory cytokines such as IL-6 and IL-1β. Furthermore, XEGMG (12 g/kg) can maintain the goblet cell number in the colons to protect the intestinal barrier and regulate the major flora such as Firmicutes, Bacteroidetes, and Muribaculaceae back to normal. Meanwhile, the expression of IL-17A in the colon tissues was significantly lower in the group of XEGMG (6, 12 g/kg) compared to H1N1 group.

DISCUSSION AND CONCLUSIONS

XEGMG can protect against H1N1 invasion involved in gut-lung axis regulation. The results provide new evidence for the protective effect of XEGMG, which is beneficial to vulnerable children.

Factors associated with parental intention to vaccinate their child against influenza, Finland, February to March, 2022: a web-based survey

BackgroundInfluenza vaccination for children aged 6 months to 6 years is included in the national vaccination programme in Finland. Although all vaccines in the programme are free of charge, national coverage of influenza vaccination among children under 3 years and 3-6 years during 2020/21 was 43% and 35% respectively, with regional differences.AimTo assess factors underlying parental vaccination intention in order to increase influenza vaccine uptake among children.MethodsWe conducted a web-based survey among parents (n = 17,844) of randomly selected eligible children (aged 6 months-6 years) in February-March 2022 in five Finnish municipalities from regions of high and low coverage. Logistic regressions were used to determine associations between vaccination intention and e.g. sociodemographic factors, attitudes and knowledge. Linkage to the national vaccination register was used to confirm realisation of vaccination intention after the study.ResultsParticipation rate was 13% (n = 2,322 parents). Influenza knowledge, trust in official information, responding parent's education level, adherence to the vaccination programme, number of children and changes in attitudes towards vaccination since COVID-19 were all associated with intention to vaccinate. Vaccination intention for children was 64%, and realised vaccination 51%.ConclusionDespite the low participation rate, both vaccinated and unvaccinated children were represented. Influenza vaccine uptake is not dependent on a single factor. Our results identified the need for open dialogue between parents and healthcare professionals, as the lack of vaccine being offered by healthcare professionals was the most reported reason for not vaccinating.

SARS-CoV-2 antibodies from children exhibit broad neutralization and belong to adult public clonotypes

From the beginning of the COVID-19 pandemic, children have exhibited different susceptibility to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, reinfection, and disease compared with adults. Motivated by the established significance of SARS-CoV-2-neutralizing antibodies in adults, here we characterize SARS-CoV-2-specific antibody repertoires in a young cohort of individuals aged from 5 months to 18 years old. Our results show that neutralizing antibodies in children possess similar genetic features compared to antibodies identified in adults, with multiple antibodies from children belonging to previously established public antibody clonotypes in adults. Notably, antibodies from children show potent neutralization of circulating SARS-CoV-2 variants that have cumulatively resulted in resistance to virtually all approved monoclonal antibody therapeutics. Our results show that children can rely on similar SARS-CoV-2 antibody neutralization mechanisms compared to adults and are an underutilized source for the discovery of effective antibody therapeutics to counteract the ever-evolving pandemic.

RDN for the treatment of influenza in children: a randomized, double-blinded, parallel-controlled clinical trial

BACKGROUND

The morbidity of influenza in children increased rapidly in decade. Reduning injection (RDN), a small but fine Chinese herbal formula, has antipyretic, antiviral, anti-inflammatory effects. We intend to evaluate the efficacy and safety of RDN for the influenza in children versus Oseltamivir, explore the possible antiviral mechanism of RDN and provide evidence-based medical evidence for rational clinical drug usage.

METHOD

We design a randomized, double-blind, double-dummy, parallel control of positive drug, multi-centre clinical study. According to the formula of mean superiority test, a total of 240 patients with influenza in children will be randomized 1:1 into the experimental group and control group. The experimental group will take RDN and Oseltamivir phosphate granule simulants and the control group will take Oseltamivir phosphate granule and RDN simulants. Each group will be treated for 5 days. The primary outcome measure is temperature recovery time, and the secondary outcome measures include time when the fever begins to subside, time and degree of disease to alleviate, disappearance rate of individual symptoms and so on. We will measure before enrollment and each 24 h after treatment for comparison.

DISCUSSION

The study is launched to evaluate the efficacy and safety of RDN for the treatment of influenza in children and to provide an alternative option for influenza in children.

TRIAL REGISTRATION

This study is registered in ClinicalTrials.gov as NCT04183725, registered on 3 December, 2019.

Transcriptomic profiles of multiple organ dysfunction syndrome phenotypes in pediatric critical influenza

Background

Influenza virus is responsible for a large global burden of disease, especially in children. Multiple Organ Dysfunction Syndrome (MODS) is a life-threatening and fatal complication of severe influenza infection.

Methods

We measured RNA expression of 469 biologically plausible candidate genes in children admitted to North American pediatric intensive care units with severe influenza virus infection with and without MODS. Whole blood samples from 191 influenza-infected children (median age 6.4 years, IQR: 2.2, 11) were collected a median of 27 hours following admission; for 45 children a second blood sample was collected approximately seven days later. Extracted RNA was hybridized to NanoString mRNA probes, counts normalized, and analyzed using linear models controlling for age and bacterial co-infections (FDR q<0.05).

Results

Comparing pediatric samples collected near admission, children with Prolonged MODS for ≥7 days (n=38; 9 deaths) had significant upregulation of nine mRNA transcripts associated with neutrophil degranulation (RETN, TCN1, OLFM4, MMP8, LCN2, BPI, LTF, S100A12, GUSB) compared to those who recovered more rapidly from MODS (n=27). These neutrophil transcripts present in early samples predicted Prolonged MODS or death when compared to patients who recovered, however in paired longitudinal samples, they were not differentially expressed over time. Instead, five genes involved in protein metabolism and/or adaptive immunity signaling pathways (RPL3, MRPL3, HLA-DMB, EEF1G, CD8A) were associated with MODS recovery within a week.

Conclusion

Thus, early increased expression of neutrophil degranulation genes indicated worse clinical outcomes in children with influenza infection, consistent with reports in adult cohorts with influenza, sepsis, and acute respiratory distress syndrome.

The Neonatal Immune System and Respiratory Pathogens

Neonates are more susceptible to some pathogens, particularly those that cause infection in the respiratory tract. This is often attributed to an incompletely developed immune system, but recent work demonstrates effective neonatal immune responses to some infection. The emerging view is that neonates have a distinctly different immune response that is well-adapted to deal with unique immunological challenges of the transition from a relatively sterile uterus to a microbe-rich world, tending to suppress potentially dangerous inflammatory responses. Problematically, few animal models allow a mechanistic examination of the roles and effects of various immune functions in this critical transition period. This limits our understanding of neonatal immunity, and therefore our ability to rationally design and develop vaccines and therapeutics to best protect newborns. This review summarizes what is known of the neonatal immune system, focusing on protection against respiratory pathogens and describes challenges of various animal models. Highlighting recent advances in the mouse model, we identify knowledge gaps to be addressed.

Knowledge, Attitudes, and Practices of Influenza Vaccination among Parents of Children with Asthma: A Cross-Sectional Study

Asthma is the most common chronic disease in childhood. Exacerbation is a significant problem for asthmatic patients, and viral infections remain the most frequent triggers of asthma exacerbations. This study explored knowledge, attitudes, and practices (KAP) of parents of asthmatic children towards providing influenza vaccine to their children. This cross-sectional study enrolled parents of asthmatic children who visited the outpatient respiratory clinics of two Jordanian hospitals. The present study enrolled 667 parents of asthmatic children (62.8% female). The median age of the participants' children was 7 years. The results showed that 60.4% of the children with asthma never received a flu vaccine. Most of those who had received the flu vaccine reported that the side effects were mild (62.7%). Asthma duration was positively and significantly associated with increased vaccine hesitancy/rejection (OR = 1.093, 95% CI = (1.004-1.190), p = 0.04; and OR = 1.092, 95% CI = (1.002-1.189), p = 0.044, respectively). As the attitude towards flu vaccine score increases, odds of vaccination hesitancy/rejection decreased (OR = 0.735, 95% CI = (0.676-0.800), p < 0.001; and OR = 0.571, 95% CI = (0.514-0.634), p < 0.001, respectively). The main reasons for vaccination hesitancy/refusal included "I don't think my child needs it" (22.3%) followed by "I forget it" (19.5%). The rate of vaccination among children was low and emphasized the necessity of encouraging parents with asthmatic children to vaccinate their children by conducting health awareness campaigns and also emphasized the role of doctors and other healthcare professionals.

Longitudinal Analysis of Contrasts in Gene Expression Data

We are interested in detecting a departure from the baseline in a longitudinal analysis in the context of multiple organ dysfunction syndrome (MODS). In particular, we are given gene expression reads at two time points for a fixed number of genes and individuals. The individuals can be subdivided into two groups, denoted as groups A and B. Using the two time points, we compute a contrast of gene expression reads per individual and gene. The age of each individual is known and it is used to compute, for each gene separately, a linear regression of the gene expression contrasts on the individual's age. Looking at the intercept of the linear regression to detect a departure from the baseline, we aim to reliably single out those genes for which there is a difference in the intercept among those individuals in group A and not in group B. In this work, we develop testing methodology for this setting based on two hypothesis tests-one under the null and one under an appropriately formulated alternative. We demonstrate the validity of our approach using a dataset created by bootstrapping from a real data application in the context of multiple organ dysfunction syndrome (MODS).

Identification and genome sequencing of an influenza H3N2 variant in wastewater from elementary schools during a surge of influenza A cases in Las Vegas, Nevada

Real-time surveillance of infectious diseases at schools or in communities is often hampered by delays in reporting due to resource limitations and infrastructure issues. By incorporating quantitative PCR and genome sequencing, wastewater surveillance has been an effective complement to public health surveillance at the community and building-scale for pathogens such as poliovirus, SARS-CoV-2, and even the monkeypox virus. In this study, we asked whether wastewater surveillance programs at elementary schools could be leveraged to detect RNA from influenza viruses shed in wastewater. We monitored for influenza A and B viral RNA in wastewater from six elementary schools from January to May 2022. Quantitative PCR led to the identification of influenza A viral RNA at three schools, which coincided with the lifting of COVID-19 restrictions and a surge in influenza A infections in Las Vegas, Nevada, USA. We performed genome sequencing of wastewater RNA, leading to the identification of a 2021-2022 vaccine-resistant influenza A (H3N2) 3C.2a1b.2a.2 subclade. We next tested wastewater samples from a treatment plant that serviced the elementary schools, but we were unable to detect the presence of influenza A/B RNA. Together, our results demonstrate the utility of near-source wastewater surveillance for the detection of local influenza transmission in schools, which has the potential to be investigated further with paired school-level influenza incidence data.

Comorbidities, multimorbidity and COVID-19

The influence of comorbidities on COVID-19 outcomes has been recognized since the earliest days of the pandemic. But establishing causality and determining underlying mechanisms and clinical implications has been challenging-owing to the multitude of confounding factors and patient variability. Several distinct pathological mechanisms, not active in every patient, determine health outcomes in the three different phases of COVID-19-from the initial viral replication phase to inflammatory lung injury and post-acute sequelae. Specific comorbidities (and overall multimorbidity) can either exacerbate these pathological mechanisms or reduce the patient's tolerance to organ injury. In this Review, we consider the impact of specific comorbidities, and overall multimorbidity, on the three mechanistically distinct phases of COVID-19, and we discuss the utility of host genetics as a route to causal inference by eliminating many sources of confounding. Continued research into the mechanisms of disease-state interactions will be crucial to inform stratification of therapeutic approaches and improve outcomes for patients.

Cocirculation of A(H3N2) and B/Victoria increased morbidity in hospitalized patients in the 2019-2020 A(H1N1)pdm09 predominant influenza season in Israel

Community surveillance found the 2019-2020 A(H1N1)pdm09 predominant influenza season in Israel to be a high-intensity season with an early and steep morbidity peak. To further characterize disease severity in the 2019-2020 season, we analyzed a cohort of hospitalized patients with laboratory-confirmed influenza from this season (n = 636). Quantitative polymerase chain reaction was performed on clinical samples to detect the presence of influenza. Demographic, clinical, and laboratory data were retrieved via electronic health records and MDClone. Electronic health records were accessed to obtain data on intensive care unit patients, missing data and for data verification purposes. Univariate analysis was performed to compare demographic, comorbidity, and clinical characteristics across the three influenza strains. The A(H1N1)pdm09 predominant 2019-2020 influenza season in Israel was characterized by an early and steep morbidity peak, vaccine delays and shortages, and with the A(H3N2) and B/Victoria strains disproportionately targeting children and young adults, most probably due to reduced immunity to these strains. A greater proportion of children <5 years infected with A(H3N2) and B/Victoria developed severe influenza compared with those infected with A(H1N1)pdm09. Our study emphasizes the vulnerability of infants and young children in the face of rapidly evolving influenza strains and underscores the importance of influenza prevention measures in this population.

Susceptibility identification for seasonal influenza A/H3N2 based on baseline blood transcriptome

Introduction

Influenza susceptibility difference is a widely existing trait that has great practical significance for the accurate prevention and control of influenza.

Methods

Here, we focused on the human susceptibility to the seasonal influenza A/H3N2 of healthy adults at baseline level. Whole blood expression data for influenza A/H3N2 susceptibility from GEO were collected firstly (30 symptomatic and 19 asymptomatic). Then to explore the differences at baseline, a suite of systems biology approaches - the differential expression analysis, co-expression network analysis, and immune cell frequencies analysis were utilized.

Results

We found the baseline condition, especially immune condition between symptomatic and asymptomatic, was different. Co-expression module that is positively related to asymptomatic is also related to immune cell type of naïve B cell. Function enrichment analysis showed significantly correlation with "B cell receptor signaling pathway", "immune response-activating cell surface receptor signaling pathway" and so on. Also, modules that are positively related to symptomatic are also correlated to immune cell type of neutrophils, with function enrichment analysis showing significantly correlations with "response to bacterium", "inflammatory response", "cAMP-dependent protein kinase complex" and so on. Responses of symptomatic and asymptomatic hosts after virus exposure show differences on resisting the virus, with more effective frontline defense for asymptomatic hosts. A prediction model was also built based on only baseline transcription information to differentiate symptomatic and asymptomatic population with accuracy of 0.79.

Discussion

The results not only improve our understanding of the immune system and influenza susceptibility, but also provide a new direction for precise and targeted prevention and therapy of influenza.

Evaluation of Pre-Pandemic Trivalent COBRA HA Vaccine in Mice Pre-Immune to Historical H1N1 and H3N2 Influenza Viruses

Initial exposure to influenza virus(es) during early childhood produces protective antibodies that may be recalled following future exposure to subsequent viral infections or vaccinations. Most influenza vaccine research studies use immunologically naïve animal models to assess vaccine effectiveness. However, most people have an extensive influenza immune history, with memory cells produced by viruses or vaccines representing multiple influenza viruses. In this study, we explored the effect influenza seasonal virus-induced immunity has on pre-pandemic influenza virus vaccination. The mice that were pre-immune to historical H1N1 and H3N2 seasonal influenza viruses were vaccinated with adjuvanted pre-pandemic (H2, H5, and H7) HA-based computationally optimized broadly reactive antigen (COBRA) vaccines, and were fully protected from lethal challenge, whereas the mock-vaccinated mice, with or without pre-immunity, were not protected from morbidity or mortality. Detectable antibody titers were present in the pre-immune mice vaccinated with a single dose of vaccine, but not in the immunologically naïve mice. The mice vaccinated twice with the trivalent COBRA HA vaccine had similar antibody titers regardless of their pre-immune status. Overall, seasonal pre-immunity did not interfere with the immune responses elicited by pre-pandemic COBRA HA vaccines or the protection against pre-pandemic viruses.

The influence of air quality and meteorological variations on influenza A and B virus infections in a paediatric population in Singapore

INTRODUCTION

Influenza is an important cause of paediatric illness across the globe. However, information about the relationships between air pollution, meteorological variability and paediatric influenza A and B infections in tropical settings is limited.

METHODS

We analysed all daily reports of influenza A and B infections in children <5 years old obtained from the largest specialist women and children's hospital in Singapore. In separate negative binomial regression models, we assessed the dependence of paediatric influenza A and B infections on air quality and meteorological variability, using multivariable fractional polynomial modelling and adjusting for time-varying confounders.

RESULTS

Approximately 80% of 7329 laboratory-confirmed reports were caused by influenza A. We observed positive associations between sulphur dioxide (SO₂) exposure and the subsequent risk of infection with both influenza types. We observed evidence of a harvesting effect of SO₂ on Influenza A but not Influenza B. Ambient temperature was associated with a decline in influenza A reports (Relative Risk at lag 5 [RR_lag5]: 0.949, 95% CI: 0.916-0.983). Rainfall was positively associated with a subsequent increase in influenza A reports (RR_lag3: 1.044, 95% CI: 1.017-1.071). Nitrogen dioxide (NO₂) concentration was positively associated with influenza B reports (RR_lag5: 1.015, 95% CI: 1.005-1.025). There was a non-linear association between CO and influenza B reports. Absolute humidity increased the ensuing risk of influenza B (RR_lag5: 4.799, 95% CI: 2.277-10.118). Influenza A and B infections displayed dissimilar but predictable within-year seasonal patterns.

CONCLUSIONS

We observed different independent associations between air quality and meteorological variability with paediatric influenza A and B infections. Anticipated seasonal infection peaks and variations in air quality and meteorological parameters can inform the timing of community measures aimed at reducing influenza infection risk.

Determinants of influenza and pneumococcal vaccine uptake among preschool children in Singapore

Young children are at increased risk of severe illness from influenza and pneumococcal infections. The World Health Organization (WHO) recommends vaccination with influenza and pneumococcal conjugate vaccine (PCV). However, in Singapore, vaccine uptake remains suboptimal relative to other routine childhood immunisations. Limited information exists regarding determinants of influenza and pneumococcal vaccine uptake in children. We estimated vaccine uptake and investigated factors associated with influenza and pneumococcal vaccination status by age group using data from a cohort study on acute respiratory infections in children attending preschools in Singapore. We recruited children aged two to six years at 24 participating preschools from June 2017 to July 2018. We determined the proportion of children immunised with influenza vaccine and PCV, and investigated socio-demographic factors associated with vaccine uptake using logistic regression models. Among 505 children, 77.5% were of Chinese ethnicity, and 53.1% were male. History of influenza vaccination was 27.5% of which 11.7% had been vaccinated within the past 12 months. In multivariable analyses, factors associated with influenza vaccine uptake were 'children living in landed property' (aOR = 2.25, 95% CI [1.07-4.67]) and 'history of hospitalisation due to cough' (aOR = 1.85, 95% CI [1.00-3.36]). Nearly three-quarters of participants (70.7% 95%CI: [66.6-74.5]) reported prior PCV vaccination. PCV uptake was higher for younger children. 'Higher parental education' (OR = 2.83, 95% CI [1.51,5.32]), 'household income' (OR = 1.26, 95% CI [1.08,1.48]) and 'smokers in household' (OR = 0.48, 95% CI [0.31,0.74]) were significantly associated with PCV uptake in univariable analyses. Only 'smokers in household' remained significantly associated with PCV uptake (aOR = 0.55, 95% CI [0.33,0.91]) in the adjusted model. Our results indicate that episodes of severe respiratory illness are a cue to influenza vaccination suggesting that doctors are more likely to recommend influenza vaccines to high-risk children. For PCV, our findings suggest overall greater awareness and education on the benefit of PCV vaccination is required.

Pertussis and influenza immunization: perceived attitude and decision of postpartum patients

BACKGROUND

Vaccination of pregnant patients with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) and influenza vaccine during influenza season can reduce maternal and fetal morbidity and mortality; nevertheless, vaccination rates remain suboptimal in this patient population. To investigate the effect of a brief educational counseling session on maternal Tdap and influenza vaccination and determine factors influencing women's decision in regards to receiving Tdap and or influenza vaccine during their pregnancy.

METHODS

A face-to-face semi-structured cross-sectional survey was administered to postpartum patients on their anticipated day of discharge (June 11-August 21, 2018). A brief educational counseling session about maternal pertussis and Tdap vaccine was provided to interested patients after which the Tdap vaccine was offered to eligible patients who did not receive it during their pregnancy or upon hospital admission. Medical records were reviewed to determine if surveyed patients were vaccinated prior to discharge.

RESULTS

Two hundred postpartum patients were surveyed on their day of anticipated discharge. Of those who were surveyed, 103 (51.5%) had received Tdap and 80 (40.0%) had received influenza vaccinations prior to hospitalization. Among immunized patients, the common facilitators were doctor's recommendation (Tdap: 68, 54.4%; influenza: 3, 6.0%), to protect their baby (Tdap: 57, 45.6%; influenza: 17, 34.0%) and for self-protection (Tdap: 17, 13.6%; Influenza: 17, 34.0%). Of the 119 participants who had not received either Tdap or influenza vaccine prior to the survey, the barriers cited were that the vaccine was not offered by the provider (Tdap: 36, 52.2%; influenza: 29, 27.6%), belief that vaccination was unnecessary (Tdap: 5, 7.2%; influenza: 9, 8.5%), safety concerns for baby (Tdap: 4, 5.8%; influenza: 2, 1.9%). Of 97 patients who were not immunized with Tdap prior to admission but were eligible to receive vaccine, 24 (25%) were vaccinated prior to survey as part of routine hospital-based screening and vaccination program, 29 (38.2%) after our survey.

CONCLUSION

Interventions to educate pregnant patients about the benefits of vaccination for their baby, addressing patient safety concerns, and vaccine administration in obstetricians' offices may significantly improve maternal vaccination rates.

Parental Attitudes and Perceptions of Support after Brief Clinician Intervention Predict Intentions to Accept the Adjuvanted Seasonal Influenza Vaccination: Findings from the Pediatric Influenza Vaccination Optimization Trial (PIVOT)-I

Adjuvanted trivalent influenza vaccine (aTIV) provides enhanced protection against seasonal influenza in children compared with nonadjuvanted trivalent influenza vaccine (TIV). This prospective cohort study assessed parental attitudes, beliefs, and intentions to vaccinate their infants aged 6-23 months with aTIV. Parents were surveyed before and after routine healthy baby visits, and post clinician interaction results were analyzed using multivariable logistic regression. Physicians at 15 community practice clinics and nurses at 3 public health clinics participated; 207 parents were surveyed. After clinician consultation, most parents considered immunization with aTIV to be safe (72.9%), effective (69.6%), and important (69.0%); most perceived support for vaccination from significant others (62.8%) and clinicians (81.6%); and 66.6% intended to vaccinate their infant with aTIV. Parental attitudes toward vaccinating their infant with aTIV were strongly correlated with perceptions of vaccine safety, efficacy, and importance, and these represented the strongest influence on intentions to vaccinate (odds ratio (OR) 79.25; 95% confidence interval (CI) 6.05-1037.50). Parental intentions were further influenced by perceived strength of clinician recommendation (OR 4.55, 95% CI 1.38-15.06) and social support for vaccination (OR 3.46, 95% CI 0.50-24.13). These findings may inform clinician approaches to parental education to ensure optimal seasonal pediatric influenza vaccination.

Clinical and Epidemiological Presentation of COVID-19 among Children in Conflict Setting

Background: This study aims to describe the observable symptoms of children with COVID-19 infection and analyze access to real-time polymerase chain reaction (RT-PCR) testing among children seeking care in Yemen. Method: In the period of March 2020−February 2022, data were obtained from 495 children suspected to have been infected with COVID-19 (from a larger register of 5634 patients) from the Diseases Surveillance and Infection Control Department at the Ministry of Public Health and Population in Aden, Yemen. Results: Overall, 21.4% of the children with confirmed COVID-19 infection were asymptomatic. Fever (71.4%) and cough (67.1%) were the most frequently reported symptoms among children, and children were less likely to have fever (p < 0.001), sore throat (p < 0.001) and cough (p < 0.001) compared to adults. A lower frequency of COVID-19-associated symptoms was reported among children with positive RT-PCR tests compared to children with negative tests. A lower rate of testing was conducted among children (25%) compared to adults (61%). Fewer tests were carried out among children <5 years (11%) compared to other age groups (p < 0.001), for children from other nationalities (4%) compared to Yemeni children (p < 0.001) and for girls (21%) compared to boys (30%) (p < 0.031). Conclusion: Understanding and addressing the cause of these disparities and improving guidelines for COVID-19 screening among children will improve access to care and control of the COVID-19 pandemic.

The Epidemiology of Influenza and the Associated Vaccines Development in China: A Review

Influenza prevention and control has been one of the biggest challenges encountered in the public health domain. The vaccination against influenza plays a pivotal role in the prevention of influenza, particularly for the elderly and small children. According to the epidemiology of influenza in China, the nation is under a heavy burden of this disease. Therefore, as a contribution to the prevention and control of influenza in China through the provision of relevant information, the present report discusses the production and batch issuance of the influenza vaccine, analysis of the vaccination status and vaccination rate of the influenza vaccine, and the development trend of the influenza vaccine in China.

Safety and Immunogenicity of Cell-Based Quadrivalent Influenza Vaccine: A Randomized Trial

OBJECTIVE

Young children are at increased risk for influenza-related complications. Safety and immunogenicity of a cell-based quadrivalent inactivated influenza vaccine (QIVc) was compared with a US-licensed vaccine (QIV) in children aged 6 through 47 months.

METHODS

A phase 3, randomized, observer-blind, comparator-controlled, multicenter study was conducted during Northern Hemisphere 2019-2020 influenza season. Children were randomized 2:1 to QIVc or QIV and received 1 or 2 doses of the vaccine, depending upon influenza vaccination history. Safety was assessed for 180 days after last vaccination and sera were collected before and 28 days after last vaccination to measure antibody titers in hemagglutination inhibition and microneutralization assays. Noninferiority criteria were met if the upper bounds of the 2-sided 95% confidence interval (CI) for the geometric mean titer ratio (QIV:QIVc) did not exceed 1.5 and for seroconversion rate difference (QIV-QIVc) did not exceed 10% for the 4 virus strains.

RESULTS

Immunogenicity was evaluated in 1092 QIVc and 575 QIV subjects. Success criteria were met for all vaccine strains. Geometric mean titer ratios (upper bound 95% CI) were A/H1N1, 0.73 (0.84); A/H3N2, 1.04 (1.16); B/Yamagata, 0.73 (0.81); and B/Victoria, 0.88 (0.97). Seroconversion differences (upper bound 95% CI) were -11.46% (-6.42), 3.13% (7.81), -14.87% (-9.98), and -5.96% (-1.44) for A/H1N1, A/H3N2, B/Yamagata, and B/Victoria, respectively. Rates of adverse events were similar between the 2 groups with no serious adverse events related to vaccination.

CONCLUSIONS

QIVc was well-tolerated and immune responses were similar to a US-licensed QIV in children 6 through 47 months of age.

Longitudinal Household Assessment of Respiratory Illness in Children and Parents During the COVID-19 Pandemic

IMPORTANCE

In the early COVID-19 pandemic, SARS-CoV-2 testing was only accessible and recommended for symptomatic persons or adults. This restriction hampered assessment of the true incidence of SARS-CoV-2 infection in children as well as detailed characterization of the SARS-CoV-2 disease spectrum and how this spectrum compared with that of other common respiratory illnesses.

OBJECTIVE

To estimate the community incidence of SARS-CoV-2 infection in children and parents and to assess the symptoms and symptom severity of respiratory illness episodes involving SARS-CoV-2-positive test results relative to those with SARS-CoV-2-negative test results.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study randomly selected Dutch households with at least 1 child younger than 18 years. A total of 1209 children and adults from 307 households were prospectively followed up between August 25, 2020, and July 29, 2021, covering the second and third waves of the COVID-19 pandemic. Participation included SARS-CoV-2 screening at 4- to 6-week intervals during the first 23 weeks of participation (core study period; August 25, 2020, to July 29, 2021). Participants in all households finishing the core study before July 1, 2021, were invited to participate in the extended follow-up and to actively report respiratory symptoms using an interactive app until July 1, 2021. At new onset of respiratory symptoms or a SARS-CoV-2 positive test result, a household outbreak study was initiated, which included daily symptom recording, repeated polymerase chain reaction testing (nose-throat swabs and saliva and fecal samples), and SARS-CoV-2 antibody measurement (paired dried blood spots) in all household members. Outbreaks, households, and episodes of respiratory illness were described as positive or negative depending on SARS-CoV-2 test results. Data on participant race and ethnicity were not reported because they were not uniformly collected in the original cohorts and were therefore not representative or informative.

EXPOSURES

SARS-CoV-2-positive and SARS-CoV-2-negative respiratory illness episodes.

MAIN OUTCOMES AND MEASURES

Age-stratified incidence rates, symptoms, and symptom severity for SARS-CoV-2-positive and SARS-CoV-2-negative respiratory illness episodes.

RESULTS

Among 307 households including 1209 participants (638 female [52.8%]; 403 [33.3%] aged <12 years, 179 [14.8%] aged 12-17 years, and 627 [51.9%] aged ≥18 years), 183 household outbreaks of respiratory illness were observed during the core study and extended follow-up period, of which 63 (34.4%) were SARS-CoV-2 positive (59 outbreaks [32.2%] during the core study and 4 outbreaks [2.2%] during follow-up). SARS-CoV-2 incidence was similar across all ages (0.24/person-year [PY]; 95% CI, 0.21-0.28/PY). Overall, 33 of 134 confirmed SARS-CoV-2 episodes (24.6%) were asymptomatic. The incidence of SARS-CoV-2-negative respiratory illness episodes was highest in children younger than 12 years (0.94/PY; 95% CI, 0.89-0.97/PY). When comparing SARS-CoV-2-positive vs SARS-CoV-2-negative respiratory illness episodes in children younger than 12 years, no differences were observed in number of symptoms (median [IQR], 2 [2-4] for both groups), symptom severity (median [IQR] maximum symptom severity score, 6 [4-9] vs 7 [6-13]), or symptom duration (median [IQR], 6 [5-12] days vs 8 [4-13] days). However, among adults, SARS-CoV-2-positive episodes had a significantly higher number (median [IQR], 6 [4-8] vs 3 [2-4]), severity (median [IQR] maximum symptom severity score, 15 [9-19] vs 7 [6-11]), and duration (median [IQR] 13 [8-29] days vs 5 [3-11] days; P < .001 for all comparisons) of symptoms vs SARS-CoV-2-negative episodes.

CONCLUSIONS AND RELEVANCE

In this cohort study, during the first pandemic year when mostly partial or full in-person learning occurred, the SARS-CoV-2 incidence rate in children was substantially higher than estimated from routine testing or seroprevalence data and was similar to that of adult household members. Unlike in unvaccinated adults, SARS-CoV-2 symptoms and symptom severity in children were similar to other common respiratory illnesses. These findings may prove useful when developing pediatric COVID-19 vaccine recommendations.

Influenza vaccine administration in a paediatric intensive care unit

AIM

We describe the clinical profile of children and outcomes of influenza immunisation for patients in a paediatric intensive care unit (PICU).

METHODS

Over two influenza seasons: 19/04/2018 to 07/08/2018 and 02/05/2019 to 10/10/2019, an immunisation nurse and PICU nurse coordinator met weekly and identified patients to receive the influenza vaccine. An inpatient list of PICU patients was screened for eligible patients: greater than 6 months of age, did not have imminent procedures (e.g. surgery) or were not critically unwell, as determined by the treating team, to receive the influenza vaccine. Patients were excluded if they had undergone surgery in the previous 24 hours or were being treated palliatively.

RESULTS

Sixty patients in PICU were identified, with 43% (26/60) receiving the vaccine while in PICU and 17% (10/60) once discharged from PICU to the general ward environment. The majority of patients immunised were in PICU due to cardiac surgery/cardiology or general medical conditions, such as cerebral palsy or RSV bronchiolitis. There were no reported adverse events following immunisation.

CONCLUSIONS

We have demonstrated the suitability and acceptability of children in the PICU receiving the seasonal influenza vaccine and tailored interventions to follow-up once discharged from PICU to optimise protection.

Relative Effectiveness of Cell-based Versus Egg-based Quadrivalent Influenza Vaccines in Children and Adolescents in the United States During the 2019-2020 Influenza Season

BACKGROUND

Egg-based influenza vaccine production can lead to the accumulation of mutations that affect antigenicity. The mammalian cell-based inactivated quadrivalent influenza vaccine (IIV4c) may improve effectiveness compared with egg-based vaccines. This study estimated the relative vaccine effectiveness (rVE) of IIV4c versus egg-based inactivated quadrivalent influenza vaccine (IIV4e) in preventing influenza-related medical encounters (IRME) among children and adolescents during the 2019-2020 US influenza season.

METHODS

This retrospective cohort study used a dataset linking primary and specialty care electronic medical records with medical and pharmacy claims data from US residents 4 through 17 years of age vaccinated with IIV4c or IIV4e during the 2019-2020 influenza season. Odds ratios (ORs) were derived from a doubly robust inverse probability of treatment-weighted approach adjusting for age, sex, race, ethnicity, region, index week, health status and two proxy variables for healthcare accessibility and use. Adjusted rVE was estimated by (1-OR adjusted )*100, and an exploratory analysis evaluated IRMEs separately for outpatient and inpatient settings.

RESULTS

The final study cohort included 60,480 (IIV4c) and 1,240,990 (IIV4e) vaccine recipients. Fewer IRMEs were reported in subjects vaccinated with IIV4c than IIV4e. The rVE for IIV4c versus IIV4e was 12.2% [95% confidence interval (CI): 7.5-16.6] for any IRME and 14.3% (9.3-19.0) for outpatient IRMEs. Inpatient IRMEs were much less frequent, and effectiveness estimates were around the null.

CONCLUSIONS

Fewer IRMEs occurred in pediatric subjects vaccinated with IIV4c versus IIV4e. These results support the greater effectiveness of IIV4c over IIV4e in this population during the 2019-2020 US influenza season.

Online searches of children’s oseltamivir in public primary and specialized care: Detecting influenza outbreaks in Finland using dedicated databases for health care professionals

Introduction

Health care professionals working in primary and specialized care typically search for medical information from Internet sources. In Finland, Physician’s Databases are online portals aimed at professionals seeking medical information. As dosage errors may occur when prescribing medication to children, professionals’ need for reliable medical information has increased in public health care centers and hospitals. Influenza continues to be a public health threat, with young children at risk of developing severe illness and easily transmitting the virus. Oseltamivir is used to treat children with influenza. The objective of this study was to compare searches for children’s oseltamivir and influenza diagnoses in primary and specialized care, and to determine if the searches could aid detection of influenza outbreaks.

Methods

We compared searches in Physician’s Databases for children’s oral suspension of oseltamivir (6 mg/mL) for influenza diagnoses of children under 7 years and laboratory findings of influenza A and B from the National Infectious Disease Register. Searches and diagnoses were assessed in primary and specialized care across Finland by season from 2012–2016. The Moving Epidemic Method (MEM) calculated seasonal starts and ends, and paired differences in the mean compared two indicators. Correlation was tested to compare seasons.

Results

We found that searches and diagnoses in primary and specialized care showed visually similar patterns annually. The MEM-calculated starting weeks in searches appeared mainly in the same week. Oseltamivir searches in primary care preceded diagnoses by −1.0 weeks (95% CI: −3.0, −0.3; p = 0.132) with very high correlation (τ = 0.913). Specialized care oseltamivir searches and diagnoses correlated moderately (τ = 0.667).

Conclusion

Health care professionals’ searches for children’s oseltamivir in online databases linked with the registers of children’s influenza diagnoses in primary and specialized care. Therefore, database searches should be considered as supplementary information in disease surveillance when detecting influenza epidemics.

Cost-utility analysis of increasing uptake of universal seasonal quadrivalent influenza vaccine (QIV) in children aged 6 months and older in Germany

Seasonal influenza causes many cases and related deaths in Europe annually, despite ongoing vaccination programs for older adults and people at high-risk of complications. Children have the highest risk of infection and play a key role in disease transmission. Our cost-utility analysis, based on a dynamic transmission model, estimated the impact of increasing the current vaccination coverage with inactivated quadrivalent influenza vaccine in Germany to all (healthy and high-risk) children under 5 years of age (40% uptake), or under 18 years (40% uptake), or only high-risk children under 18 years (90% uptake). Eight influenza complications were modeled, hospitalization and death rates were based on age and risk status. All three vaccination strategies provided more health benefits than the existing vaccination situation, reducing influenza cases, complications, hospitalizations and deaths across the entire population. The strategy targeting all children under 5 years was highly cost-effective (€6/quality-adjusted life-year gained, payer perspective). The other strategies were cost saving from the payer and societal perspectives. The vaccination strategy targeting all children under 18 years was estimated to provide the most health benefits (preventing on average 1.66 million cases, 179,000 complications, 14,000 hospitalizations and 3,600 deaths due to influenza annually) and the most cost savings (annually €20.5 million and €731.3 million from payer and societal perspectives, respectively). Our analysis provides policy decision-makers with evidence supporting strategies to expand childhood influenza vaccination, to directly protect children, and indirectly all other unvaccinated age groups, in order to reduce the humanistic and economic burden on healthcare systems and society.

Clinical characteristics and outcomes of mixed virus or bacterial infection in children with laboratory-confirmed influenza infection

BACKGROUND/PURPOSE

This study investigated the demographic characteristics and influenza complications of paediatric patients and explored the association of different influenza virus types and viral and bacterial coinfections with disease severity.

METHODS

This retrospective cohort study used data collected in 2010-2016 from the Chang Gung Research Database (CGRD), the largest collection of multi-institutional electronic medical records in Taiwan. Data were retrieved for children aged 0-18 years with laboratory-confirmed influenza. We extracted and analysed the demographic characteristics and the data on clinical features, complications, microbiological information, and advanced therapies of each case.

RESULTS

We identified 6193 children with laboratory-confirmed influenza, of whom 1964 (31.7%) were hospitalised. The age of patients with influenza A infection was lower than that of patients with influenza B (4.48 vs. 6.68, p < 0.001). Patients with influenza B infection had a higher incidence of myositis or rhabdomyolysis (4.4%, p < 0.001) and a higher need for advanced therapies (OR, 1.96; 95% CI, 1.32-2.9, p < 0.001). In addition to bacterial (OR, 9.07; 95% CI, 5.29-15.54, p < 0.001) and viral coinfection (OR, 7.73; 95% CI, 5.4-11.07, p < 0.001), dual influenza A and B infection was also a risk factor for influenza complications (OR, 2.13; 95% CI, 1.47-3.09, p < 0.001).

CONCLUSION

Dual influenza A and B infection and bacterial coinfection can contribute to influenza complications. Early recognition of any influenza complication is critical for the timely initiation of organ-specific advanced therapies to improve influenza-associated outcomes.

Comparison of the medical burden of COVID-19 with seasonal influenza and measles outbreaks

AIM

To examine and compare the medical burden of measles, influenza and COVID-19 outbreaks in the city of Bnei Brak, Israel.

METHODS

The study was conducted during 2018-2021. The numbers of hospitalisations for these infections and their complications were recorded. Hospitalisation rates were determined by using the number of children residing in Bnei Brak and hospitalised with these infections during the study period as the numerators. The denominators were the estimated paediatric cases of measles, influenza and COVID-19 in Bnei Brak and were calculated under both pragmatic and conservative assumptions.

RESULTS

A total of 247, 65 and 32 children were hospitalised with influenza, COVID-19 and measles respectively. Complication rates were higher following measles than after influenza and SARS-CoV-2 infections. Hospitalisation rates were 10% for measles, 0.6%-1.2% for influenza and 0.15% - 0.25% for COVID-19 infections. Relative risks (RR) with 95% confidence intervals (CI) for hospitalisation following measles compared with COVID-19 ranged from 42 (26.3-67.3) to 70.1 (43.8-112.1), while the relative risks for influenza hospitalisation ranged from 2.5 (1.83-3.41) to 8.2 (6.0-11.2), compared with COVID-19 infection.

CONCLUSION

Hospitalisation rates and direct medical burdens of measles and influenza were significantly higher than those of COVID-19 infection in children.

Bacterial Gut Microbiota and Infections During Early Childhood

Gut microbiota composition during the first years of life is variable, dynamic and influenced by both prenatal and postnatal factors, such as maternal antibiotics administered during labor, delivery mode, maternal diet, breastfeeding, and/or antibiotic consumption during infancy. Furthermore, the microbiota displays bidirectional interactions with infectious agents, either through direct microbiota-microorganism interactions or indirectly through various stimuli of the host immune system. Here we review these interactions during childhood until 5 years of life, focusing on bacterial microbiota, the most common gastrointestinal and respiratory infections and two well characterized gastrointestinal diseases related to dysbiosis (necrotizing enterocolitis and Clostridioides difficile infection). To date, most peer-reviewed studies on the bacterial microbiota in childhood have been cross-sectional and have reported patterns of gut dysbiosis during infections as compared to healthy controls; prospective studies suggest that most children progressively return to a "healthy microbiota status" following infection. Animal models and/or studies focusing on specific preventive and therapeutic interventions, such as probiotic administration and fecal transplantation, support the role of the bacterial gut microbiota in modulating both enteric and respiratory infections. A more in depth understanding of the mechanisms involved in the establishment and maintenance of the early bacterial microbiota, focusing on specific components of the microbiota-immunity-infectious agent axis is necessary in order to better define potential preventive or therapeutic tools against significant infections in children.

Similar severity of influenza primary and re-infections in pre-school children requiring outpatient treatment due to febrile acute respiratory illness: prospective, multicentre surveillance study (2013-2015)

Background

Influenza virus infections in immunologically naïve children (primary infection) may be more severe than in children with re-infections who are already immunologically primed. We compared frequency and severity of influenza virus primary and re-infections in pre-school children requiring outpatient treatment.

Methods

Influenza-unvaccinated children 1–5 years of age presenting at pediatric practices with febrile acute respiratory infection < 48 h after symptom onset were enrolled in a prospective, cross-sectional, multicenter surveillance study (2013–2015). Influenza types/subtypes were PCR-confirmed from oropharyngeal swabs. Influenza type/subtype-specific IgG antibodies serving as surrogate markers for immunological priming were determined using ELISA/hemagglutination inhibition assays. The acute influenza disease was defined as primary infection/re-infection by the absence/presence of influenza type-specific immunoglobulin G (IgG) and, in a second approach, by the absence/presence of subtype-specific IgG. Socio-demographic and clinical data were also recorded.

Results

Of 217 influenza infections, 178 were due to influenza A (87 [49%] primary infections, 91 [51%] re-infections) and 39 were due to influenza B (38 [97%] primary infections, one [3%] re-infection). Children with “influenza A primary infections” showed fever with respiratory symptoms for a shorter period than children with “influenza A re-infections” (median 3 vs. 4 days; age-adjusted p = 0.03); other disease characteristics were similar. If primary infections and re-infections were defined based on influenza A subtypes, 122 (87%) primary infections (78 “A(H3N2) primary infections”, 44 “A(H1N1)pdm09 primary infections”) and 18 (13%) re-infections could be classified (14 “A(H3N2) re-infections” and 4 “A(H1N1)pdm09 re-infections”). Per subtype, primary infections and re-infections were of similar disease severity. Children with re-infections defined on the subtype level usually had non-protective IgG titers against the subtype of their acute infection (16 of 18; 89%). Some patients infected by one of the influenza A subtypes showed protective IgG titers (≥ 1:40) against the other influenza A subtype (32/140; 23%).

Conclusions

Pre-school children with acute influenza A primary infections and re-infections presented with similar frequency in pediatric practices. Contrary to expectation, severity of acute “influenza A primary infections” and “influenza A re-infections” were similar. Most “influenza A re-infections” defined on the type level turned out to be primary infections when defined based on the subtype. On the subtype level, re-infections were rare and of similar disease severity as primary infections of the same subtype. Subtype level re-infections were usually associated with low IgG levels for the specific subtype of the acute infection, suggesting only short-time humoral immunity induced by previous infection by this subtype. Overall, the results indicated recurring influenza virus infections in this age group and no or only limited heterosubtypic antibody-mediated cross-protection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06988-7.

Influenza: Toward understanding the immune response in the young

Annually influenza causes a global epidemic resulting in 290,000 to 650,000 deaths and extracts a massive toll on healthcare and the economy. Infants and children are more susceptible to infection and have more severe symptoms than adults likely mitigated by differences in their innate and adaptive immune responses. While it is unclear the exact mechanisms with which the young combat influenza, it is increasingly understood that their immune responses differ from adults. Specifically, underproduction of IFN-γ and IL-12 by the innate immune system likely hampers viral clearance while upregulation of IL-6 may create excessive damaging inflammation. The infant's adaptive immune system preferentially utilizes the Th-2 response that has been tied to γδ T cells and their production of IL-17, which may be less advantageous than the adult Th-1 response for antiviral immunity. This differential immune response of the young is considered to serve as a unique evolutionary adaptation such that they preferentially respond to infection broadly rather than a pathogen-specific one generated by adults. This unique function of the young immune system is temporally, and possibly mechanistically, tied to the microbiota, as they both develop in coordination early in life. Additional research into the relationship between the developing microbiota and the immune system is needed to develop therapies effective at combating influenza in the youngest and most vulnerable of our population.

Serum Calprotectin Is a Valid Biomarker in Distinction of Bacterial Urinary Tract Infection From Viral Respiratory Illness in Children Under 3 Years of Age

BACKGROUND

Febrile illnesses in young children can be a major diagnostic challenge, despite the routine use of various laboratory markers. Recent advancements in the understanding of inflammatory processes have highlighted the role of calprotectin, a heterodimer consisting of S100A8 and S100A9 proteins, with many studies suggesting its clinical value as a biomarker of inflammation. This research aimed to evaluate the usefulness of serum calprotectin (sCal) as a biomarker of urinary tract infection (UTI), which was due to its high pooled prevalence and feasibility of urine culture as a diagnostic reference standard selected for a model of bacterial infection in children.

METHODS

Febrile children aged 0-36 months with suspected UTI based on positive urinalysis or viral respiratory tract infection were included. Children with significant bacteriuria in urine culture were labeled as cases (n = 58), while those with confirmed viral infection (n = 51), as well as those with suspected UTI but sterile urine culture who went on to develop symptoms consistent with viral respiratory infection (n = 7), were labeled as controls. sCal levels were determined by a commercial immunoassay. Conventional inflammation markers (C-reactive protein, procalcitonin, white blood cell count, absolute neutrophil count, and neutrophil percentage) were measured on the day of the clinical examination. Differences in measured inflammatory markers between cases and controls were analyzed with Mann-Whitney U-test. ROC analysis reported cut-off values with the best sensitivity and specificity to distinguish bacterial UTI from viral respiratory infection.

RESULTS

All analyzed inflammatory biomarkers, including sCal, were significantly higher in cases than in controls. Median concentration of sCal was 4.97 μg/mL (IQR 3.43-6.42) and 2.45 μg/mL (IQR 1.63-3.85) for cases and controls, respectively (p < 0.001). For identifying bacterial UTI, sensitivity and specificity of sCal were 77.6 and 69.0%, respectively, at an adjusted cut-off point of >3.24 μg/mL (AUC 80.2%).

CONCLUSION

sCal could have substantial added value in the management of a child with fever and positive urinalysis and is a promising biomarker in distinction between bacterial UTI and viral respiratory causes of febrile illness in children under the age of 3 years.

Should coronavirus policies remain in place to prevent future paediatric influenza deaths?

The 2019-2020 to 2020-2021 influenza seasons in the USA saw a dramatic 99.5% decrease in paediatric mortality, with only one influenza death recorded during the latter season. This decrease has been attributed to a substantial reduction in transmission, resulting from the various restrictive measures enacted during the COVID-19 pandemic, onset March 2020. The relative disappearance of influenza raises specific policy questions, such as whether these measures should be kept in place after COVID-19 transmission reaches acceptable levels or herd immunity is achieved. Given the nature of these measures as liberty restricting, it is worth discussing their intended outcome and what values they promote. Do these measures in fact promote health, or simply give the comfort of safety while undermining long-term health and individual liberties? I argue that the year-long endurance of the pandemic well into 2021 may have flattened our value landscape into one where health reigns supreme. Discussions are underway regarding whether we should modify previously accepted health risks, such as the risk of contracting influenza. In this paper, I attempt to clarify the values that motivate our policies and discuss how our present historical context has appreciated the value of health. I also provide an analysis of various pandemic policies and their relation to influenza paediatric deaths. Ultimately, the cost of certain measures on values such as education, socialisation and liberty, among others, is too high to justify their use beyond regulating the spread of COVID-19.