Impact of live attenuated influenza vaccination programme for healthy children in Northern Ireland: A comparison of seven influenza seasons, 2010/11–2016/17

Seasonal influenza vaccination for healthy children was introduced in Northern Ireland in the 2013/14 flu season, with an initial pilot year involving two specific cohorts, followed by rollout to all children aged 4–11 years in subsequent seasons. This study aimed to examine the impact of that programme on the burden of flu in primary care over the study period 2010/11–2016/17.Two routine indicators were used to measure impact – GP in-hour consultations and out-of-hour calls for influenza and influenza-like-illness (ILI). Analysis was conducted overall and stratified by age; rates in children under 14 years of age to measure direct impact and rates in individuals 14 years and over to measure indirect impact. Seven influenza seasons were included, three pre-programme seasons (2010/11–2012/13: phase 0), one pilot season (2013/14: phase 1), and three post-programme seasons (2014/15–2016/17: phase 2).High uptake of vaccination was observed from the programme introduction, with consistent uptake of over 50% in pre-school age groups and over 75% in primary school age groups. Statistically significant reductions were found in GP in-hours consultations and in out-of-hour calls in phase 2 compared to phase 0, both overall (GP in-hours RR 0.61, 95% CI 0.38–0.98, p = .040; out-of-hours RR 0.51, 95% CI 0.27–0.97, p = .041) and in the under 14 years group (GP in-hours RR 0.38, 95% CI 0.19–0.75, p = .006; out-of-hours RR 0.39, 95% CI 0.19–0.83, p = .014).Our results suggest that there have been reductions in the burden of flu in primary care settings overall and in children aged under 14 years in the seasons since the introduction of healthy children influenza vaccination. Further seasons should be added to subsequent analyses to strengthen this evidence.     

Impact of prior vaccination on antibody response and influenza-like illness among Australian healthcare workers after influenza vaccination in 2016

BackgroundEpidemiological studies suggest that influenza vaccine effectiveness decreases with repeated administration. We examined antibody responses to influenza vaccination among healthcare workers (HCWs) by prior vaccination history and determined the incidence of influenza infection.MethodsHCWs were vaccinated with the 2016 Southern Hemisphere quadrivalent influenza vaccine. Serum samples were collected pre-vaccination, 21–28 days and 7 months post-vaccination. Influenza antibody titres were measured at each time-point using the haemagglutination inhibition (HI) assay. Immunogenicity was compared by prior vaccination history.ResultsA total of 157 HCWs completed the study. The majority were frequently vaccinated, with only 5 reporting no prior vaccinations since 2011. Rises in titres for all vaccine strains among vaccine-naïve HCWs were significantly greater than rises observed for HCWs who received between 1 and 5 prior vaccinations (p < 0.001, respectively). Post-vaccination GMTs against influenza A but not B strains decreased as the number of prior vaccinations increased from 1 to 5. There was a significant decline in GMTs post-season for both B lineages. Sixty five (41%) HCWs reported at least one influenza-like illness episode, with 6 (4%) identified as influenza positive.ConclusionsVarying serological responses to influenza vaccination were observed among HCWs by prior vaccination history, with vaccine-naïve HCWs demonstrating greater post-vaccination responses against A(H3N2).     

Invasive pneumococcal disease in children under 16 years of age: Incomplete rebound in incidence after the maximum effect of PCV13 in 2012/13 in Germany

ObjectiveTo identify a potential nadir of the impact of pneumococcal conjugate vaccination (PCV) in infancy on invasive pneumococcal diseases (IPD) in children under 16 in Germany.MethodsActive surveillance on IPD based on two independent data sources with capture-recapture correction for underreporting. Annual incidence rates by age group, serotypes, site of infection, and relative incidence reduction compared to pre-vaccination period (1997–2001) at nadir and for the most recent season are reported. We calculated vaccine coverage at the age of 24 months using health insurance claims data.Results96–97% of children had received at least two doses of PCV since 2009. The maximum impact on overall IPD incidence was achieved in 2012/13 (−48% [95% CI: −55%; −39%]) with a rebound to −26% [95% CI: −36%; −16%] in 2015/16. Non-PCV13 serotypes accounted for 84.1% of the IPD cases in 2015/16. The most frequent non-PCV serotypes in IPD in 2014/15 and 2015/16 were 10A, 24F, 15C, 12F, 38, 22F, 23B, and 15B. The impact at nadir was highest in children 0–1 years of age both in meningitis and non-meningitis cases, whereas the impact for other age groups was higher for meningitis cases. The rebound mainly pertained to non-meningitis cases.ConclusionThe maximum impact of pneumococcal conjugate vaccination has been attained and signs of a rebound are apparent. Sustained surveillance for IPD in children is warranted to assess whether these trends will continue. There may be a need for vaccines using antigens common to all serotypes.     

Guillain-Barré Syndrome Surveillance during National Influenza Vaccination Campaign,New York,USA, 2009

The New York State Department of Health (NYSDOH) collected information about hospitalized patients with Guillain-Barré syndrome (GBS) during October 2009–May 2010, statewide (excluding New York City), to examine a possible relationship with influenza A(H1N1)pdm09 vaccination. NYSDOH established a Clinical Network of neurologists and 150 hospital neurology units. Hospital discharge data from the Statewide Planning and Research Cooperative System (SPARCS) were used to evaluate completeness of reporting from the Clinical Network. A total of 140 confirmed or probable GBS cases were identified: 81 (58%) from both systems, 10 (7%) from Clinical Network only, and 49 (35%) from SPARCS-only. Capture–recapture methods estimated that 6 cases might have been missed by both systems. Clinical Network median reporting time was 12 days versus 131 days for SPARCS. In public health emergencies in New York State, a Clinical Network may provide timely data, but in our study such data were less complete than traditional hospital discharge data.     

Determinants of influenza vaccination among young Taiwanese children

ObjectiveAccording to the Health Belief Model (HBM), individual perceptions of susceptibility, severity, benefit, barrier, self-efficacy, and cues to action are associated with health actions. In this study, we investigated the perceptions and social factors that influence the intention to vaccinate children against influenza among parents of young Taiwanese children.MethodsA nationwide survey was performed using stratified random sampling to explore the beliefs, attitudes, and intentions of parents/main caregivers with regard to vaccinating children aged 6 months to 3 years against influenza. A questionnaire was developed based on the HBM and multivariate logistic regression analyses of 1300 eligible participants were used to identify significant predictors of the intention to vaccinate.ResultsGreater perceived benefit, cues to action, and self-efficacy of childhood vaccination against influenza were positively associated with the intention to vaccinate. Children's experience of influenza vaccinations in the past year was also a positive predictor. However, perceived susceptibility, perceived severity regarding influenza and perceived barriers to vaccination were not predictive of the intention to vaccinate.ConclusionIn addition to perceived benefits and cues to action, self-efficacy of parents/main caregivers was significantly predictive of their intention to accept influenza vaccination for their young children. These components of the HBM could be used in formulating strategies aimed at promoting the use of influenza vaccine.     

Public Preferences for Policies to Promote COVID-19 Vaccination Uptake: A Discrete Choice Experiment in The Netherlands

ObjectivesThe COVID-19 pandemic forms an unprecedented public health, economic, and social crisis. Uptake of vaccination is critical for controlling the pandemic. Nevertheless, vaccination hesitancy is considerable, requiring policies to promote uptake. We investigate Dutch citizens’ preferences for policies that aim to promote vaccination through facilitating choice of vaccination, profiling it as the norm, making vaccination more attractive through rewards, or punishing people who reject vaccination.MethodsWe conducted a discrete choice experiment in which 747 respondents were asked to choose between policies to promote vaccination uptake and their impacts on the number of deaths, people with permanent health problems, households with income loss, and a tax increase.ResultsRespondents generally had a negative preference for policies that promote vaccination. They particularly disliked policies that punish those who reject the vaccine and were more favorable toward policies that reward vaccination, such as awarding additional rights to vaccinated individuals through vaccination passports. Respondents who reject vaccination were in general much more negative about the policy options than respondents who consider accepting the vaccine. Nevertheless, vaccination passports are supported by both respondents who accept the vaccine, those who reject vaccination, and those who are unsure about vaccination.ConclusionsThis study provides concrete directions for governments attempting to increase the vaccination uptake in ways that are supported by the public. Our results could encourage policy makers to focus on policy options that make vaccination easier and reward people who take the vaccine, as especially the implementation of vaccination passports was supported.