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Introduction: In 2013, the United Kingdom began to roll‐out a universal annual influenza vaccination program for children. An important component of any new vaccination program is measuring its effectiveness. Live‐attenuated influenza vaccines (LAIVs) have since shown mixed results with vaccine effectiveness (VE) varying across seasons and countries elsewhere. This study aims to assess the effectiveness of influenza vaccination in children against severe disease during the first three seasons of the LAIV program in England. Methods: Using the screening method, LAIV vaccination coverage in children hospitalized with laboratory‐confirmed influenza infection was compared with vaccination coverage in 2–6‐year‐olds in the general population to estimate VE in 2013/14–2015/16. Results: The overall LAIV VE, adjusted for age group, week/month and geographical area, for all influenza types pooled over the three influenza seasons was 50.1% (95% confidence interval [CI] 31.2, 63.8). By age, there was evidence of protection against hospitalization from influenza vaccination in both the pre‐school (2–4‐year‐olds) (48.1%, 95% CI 27.2, 63.1) and school‐aged children (5–6‐year‐olds) (62.6%, 95% CI 2.6, 85.6) over the three seasons. Conclusion: LAIV vaccination in children provided moderate annual protection against laboratory‐confirmed influenza‐related hospitalization in England over the three influenza seasons. This study contributes further to the limited literature to date on influenza VE against severe disease in children. [ABSTRACT FROM AUTHOR]

This systematic review assesses the literature for estimates of influenza vaccine effectiveness (IVE) against laboratory-confirmed influenza-associated hospitalization in children. Studies of any design to June 8, 2020, were included if the outcome was hospitalization, participants were 17 years or younger and influenza infection was laboratory-confirmed. A random-effects meta-analysis of 37 studies that used a test-negative design gave a pooled seasonal IVE against hospitalization of 53.3% (47.2–58.8) for any influenza. IVE was higher against influenza A/H1N1pdm09 (68.7%, 56.9–77.2) and lowest against influenza A/H3N2 (35.8%, 23.4–46.3). Estimates by vaccine type ranged from 44.3% (30.1–55.7) for live-attenuated influenza vaccines to 68.9% (53.6–79.2) for inactivated vaccines. IVE estimates were higher in seasons when the circulating influenza strains were antigenically matched to vaccine strains (59.3%, 48.3–68.0). Influenza vaccination gives moderate overall protection against influenza-associated hospitalization in children supporting annual vaccination. IVE varies by influenza subtype and vaccine type. [ABSTRACT FROM AUTHOR]

Background: During the first wave of the influenza A(H1N1)pdm09 pandemic in England in 2009, morbidity and mortality were higher in patients of South Asian (Indian, Pakistani or Bangladeshi) ethnic minority groups. Objectives: This study aims to provide insights in the representation of this group among reported cases, indicating susceptibility and exposure. Methods: All laboratory‐confirmed cases including basic demographic and limited clinical information that were reported to the FluZone surveillance system between April and October 2009 were retrieved. Missing ethnicity data were imputed using the previously developed and validated South Asian Names and Group Recognition Algorithm (SANGRA). Differences between ethnic groups were calculated using chi‐square, log‐rank and t tests and rate ratios. Geographic clustering was compared using Ripley's K functions. Results: SANGRA identified 2447 (28%) of the total of 8748 reported cases as South Asian. South Asian cases were younger (P <.001), more often male (P =.002) and more often from deprived areas (P <.001) than cases of other ethnic groups. Time between onset of symptoms and laboratory sampling was longer in this group (P <.001), and they were less often advised antiviral treatment (P <.001), however, declined treatment less. The highest cumulative incidence was seen in the West Midlands region (32.7/10 000), London (7.0/10 000) and East of England region (5.7/10 000). Conclusions: People of South Asian ethnic groups were disproportionally affected by the first wave of the influenza pandemic in England in 2009. The findings presented contribute to further understanding of demographic, socioeconomic and ethnic factors of the outbreak and inform future influenza preparedness to ensure appropriate prevention and care. [ABSTRACT FROM AUTHOR]

School closure is often considered as an influenza control measure, but its effects on transmission are poorly understood. We used 2 approaches to estimate how school holidays affect the contact parameter (the per capita rate of contact sufficient for infection transmission) for influenza using primary care data from England and Wales (1967-2000). Firstly, we fitted an age-structured susceptible-infectious-recovered model to each year's data to estimate the proportional change in the contact parameter during school holidays as compared with termtime. Secondly, we calculated the percentage difference in the contact parameter between holidays and termtime from weekly values of the contact parameter, estimated directly from simple mass-action models. Estimates were combined using random-effects meta-analysis, where appropriate. From fitting to the data, the difference in the contact parameter among children aged 5-14 years during holidays as compared with termtime ranged from a 36% reduction to a 17% increase; estimates were too heterogeneous for meta-analysis. Based on the simple mass-action model, the contact parameter was 17% (95% confidence interval: 10, 25) lower during holidays than during termtime. Results were robust to the assumed proportions of infections that were reported and individuals who were susceptible when the influenza season started. We conclude that school closure may reduce transmission during influenza outbreaks. [ABSTRACT FROM AUTHOR]

Objective: To describe Ontario Telehealth usage for respiratory complaints during normal (i.e., interpandemic) circumstances. Methods: Descriptive analyses were conducted on symptom calls of a respiratory nature made to Ontario (Canada) Telehealth during a 25-month period. Results: Approximately 300,000 calls were made during the period under study, peaking annually in January/February. Calls were above average during the weekend and Mondays (p <0.0001). All-ages consultation rate was 0.21/1,000 (range, 0.11-0.43 ). Standardized call rates suggested an inverse relationship between age and call rate (except for >65 years of age). During peak activity, weekly telehealth call rates were up to more than twice the weekly mean and up to four times as high as the lowest weekly rate. Highest call rate was for under 5 years old (158.4/1,000). Male rates exceed female call rates in younger age groups; the pattern reversed in older age groups. The relationship between income and call pattern showed that income and call patterns were (1) directly related for under 5 years old, (2) inversely related for callers aged 45 years and above, and (3) bimodal (higher call rates in both the highest and lowest income groups) for callers 5-44 years old. Discussion: The advent of annual respiratory illness seasons under study here resulted in surge capacity. Data such as these can and should be used for exercises such as seasonal and pandemic forecasting. Also, recent pandemic experience has showed us monitoring both overall exceedances in usage and deviances from established demographic patterns could enhance existing routine surveillance. [ABSTRACT FROM AUTHOR]

The transmissibility of the strain of influenza virus which caused the 1968 influenza pandemic is poorly understood. Increases in outbreak size between the first and second waves suggest that it may even have increased between successive waves. The authors estimated basic and effective reproduction numbers for both waves of the 1968 influenza pandemic. Epidemic curves and overall attack rates for the 1968 pandemic, based on clinical and serologic data, were retrieved from published literature. The basic and effective reproduction numbers were estimated from 46 and 17 data sets for the first and second waves, respectively, based on the growth rate and/or final size of the epidemic. Estimates of the basic reproduction number (R0) were in the range of 1.06–2.06 for the first wave and, assuming cross-protection, 1.21–3.58 in the second. Within each wave, there was little geographic variation in transmissibility. In the 10 settings for which data were available for both waves, R0 was estimated to be higher during the second wave than during the first. This might partly explain the larger outbreaks in the second wave as compared with the first. This potential for change in viral behavior may have consequences for future pandemic mitigation strategies. [ABSTRACT FROM PUBLISHER]

Background: Interventions to increase hand washing in schools have been advocated as a means to reduce the transmission of pandemic influenza and other infections. However, the feasibility and acceptability of effective school-based hygiene interventions is not clear. Methods: A pilot study in four primary schools in East London was conducted to establish the current need for enhanced hand hygiene interventions, identify barriers to their implementation and to test their acceptability and feasibility. The pilot study included key informant interviews with teachers and school nurses, interviews, group discussions and essay questions with the children, and testing of organised classroom hand hygiene activities. Results: In all schools, basic issues of personal hygiene were taught especially in the younger age groups. However, we identified many barriers to implementing intensive hygiene interventions, in particular time constraints and competing health issues. Teachers' motivation to teach hygiene and enforce hygienic behaviour was primarily educational rather than immediate infection control. Children of all age groups had good knowledge of hygiene practices and germ transmission. Conclusion: The pilot study showed that intensive hand hygiene interventions are feasible and acceptable but only temporarily during a period of a particular health threat such as an influenza pandemic, and only if rinse-free hand sanitisers are used. However, in many settings there may be logistical issues in providing all schools with an adequate supply. In the absence of evidence on effectiveness, the scope for enhanced hygiene interventions in schools in high income countries aiming at infection control appears to be limited in the absence of a severe public health threat. [ABSTRACT FROM AUTHOR]

Background. The importance of respiratory syncytial virus (RSV) infection in adults is not well known, because laboratory testing for RSV infection is not routine. Both RSV infection and influenza are seasonally related, and it is difficult to disentangle one from the other and to disentangle infection from the season and the cold. Methods. Emergency hospitalizations for respiratory disease from April 1994 to March 2001 were analyzed in relation to surveillance data on RSV infection and influenza, using Poisson regression models adapted for time series and adjusted for season, outdoor temperature, and other covariates. Age-specific admission rates attributable to the viruses were also estimated. Results. Most of the crude relationships of emergency admissions of patients with RSV infection were confounded by season and, to a lesser extent, by cold temperatures. After adjustment for all covariates, including influenza, a 10th–90th percentile increase in RSV counts (defined as the daily number of laboratory reports of RSV) was associated with a rate ratio of 1.36 (95% CI, 1.27–1.45) for emergency admissions for respiratory disease in infants. The rate of hospitalization attributable to RSV infection in children aged <1 year was 5 per 1000 infants per year. The association in people ⩾65 years old was much smaller (rate ratio, 1.09; 95% CI, 1.04–1.14; attributable rate of hospitalization , 0.7 per 1000 population); but unlike the association in infants, this association became smaller as the lag (interval) between infection and hospital admission became shorter. Admission rates attributable to influenza were highest in the ⩾65-year age group (1.1 per 1000 population), but it was very small at younger ages. Conclusions. RSV infection appears to be an important determinant of hospitalization in infants in this data set but appears less certain for older persons and requires further investigation. [ABSTRACT FROM AUTHOR]