Physicians’ recommendations to their patients concerning a novel pandemic vaccine: a cross-sectional survey of the 2009 influenza A/H1N1 pandemic in Japan

Objectives  

Striking a balance between the rapid availability of a novel vaccine while ensuring its safety, quality, and efficacy is a major challenge during a pandemic. We aimed to elucidate physicians’ attitudes regarding the novel vaccine during the influenza A/H1N1 pandemic of 2009, and to determine factors that affected their vaccination recommendations to patients.     

Attitudes,believes, determinants and organisational barriers behind the low seasonal influenza vaccination uptake in healthcare workers – A cross-sectional survey

BackgroundSeasonal influenza threatens hospitalised patients and residents of nursing homes annually. Due to age and chronic disease their protection following immunisation is diminished. Additional immunisation of direct contacts and in particular healthcare workers (HCWs) has proven added value. As vaccination coverage in HCWs remains low, we aimed to gain insight in the factors behind the demotivation for influenza vaccination.MethodsAttitudes and believes towards influenza vaccination and socio-demographic and professional determinants were surveyed in 5141 Belgian HCWs from 13 hospitals and 14 nursing homes. Additionally, influenza campaign coordinators of the participating healthcare institutions were interviewed about the factors of success/failure in their campaigns.ResultsThe mean vaccination coverage registered by the participating healthcare institutions was 40.4% in the hospitals and 45.3% in the nursing homes. Overall, up to 90% of HCWs found it important not to infect their patients. However, only 20% of non-vaccinated HCWs considered influenza vaccination a duty to not harm their patients. Up to 40% of unvaccinated staff believed they could get influenza after vaccination and that vaccination weakens their immune system. Also, only about 20% of unvaccinated staff thought to have a high chance of getting influenza. Reasons for unvaccinated staff to get vaccinated in the future are self-protection and protection of family members. Factors that positively influenced vaccination coverage are encouragement by supervisors (OR, hospitals: 7.1, p < 0.001; nursing homes: 7.5, p < 0.001) and well-organized vaccination campaigns with on-site vaccination. Factors that negatively affected vaccination coverage are misconceptions about influenza and its vaccine (OR, range 0.1–0.7, p < 0.001 for most misconceptions) and underestimation of the risk of contracting influenza by patients or HCWs (OR of perceived susceptibility, range 2.1–5.1, p < 0.001 for most factors).ConclusionThere is a need for guidance for the organization of seasonal influenza campaigns, in which education, communication and easy accessible vaccination are promoted.     

Chinese urban–rural disparity in pandemic (H1N1) 2009 vaccination coverage rate and associated determinants: a cross-sectional telephone survey

Objectives

The present study aimed to examine the differences in pandemic (H1N1) 2009 vaccination coverage rate between urban and rural areas in China, and to explore factors associated with any urban–rural differences.

Study design

Cross-sectional study.

Methods

Data were derived from a cross-sectional telephone survey performed in seven urban and two rural areas soon after the pandemic peak in China, concerning pandemic (H1N1) 2009 vaccination and associated knowledge, attitudes and practices among the general population in China. A total of 10 669 participants aged 18 years and above participated in the study.

Results

Vaccination amongst rural residents was less than urban residents (8.9% vs 11.2%, P = 0.002). Among those who have not been immunized, 82.2% of rural respondents showed a willingness to get vaccinated against A/H1N1, significantly higher than that of urban respondents (55.3%). The major barrier to vaccination was reported as ‘not being informed to get vaccination’, of which there was a greater proportion in rural than urban population (71.9% vs 68.8%, P = 0.009). The analysis revealed a number of factors which contribute to this disparity: previous experience of vaccination against flu, degree of awareness of the free vaccination policy, and sociodemographic differences between urban and rural areas.

Conclusions

Significant discrepancies existed in the pandemic (H1N1) 2009 vaccination coverage rate and associated determinants, as well as the intention to get vaccinated between urban and rural residents. To improve the effectiveness of similar vaccination programmes in the future, campaigns for rural people need to be specifically tailored to address disparities in uptake.     

Guillain-Barré syndrome and H1N1 (2009) pandemic influenza vaccination using an AS03 adjuvanted vaccine in the United Kingdom: self-controlled case series

In 1976 a swine influenza vaccine was associated with an increased risk of Guillain-Barré syndrome (GBS). Although subsequent studies did not find an increased risk of GBS following seasonal influenza vaccine, there was concern that the monovalent H1N1 vaccines developed against the swine influenza pandemic of 2009 might increase the risk of GBS. In the UK a split-virion AS03 oil-in-water adjuvanted vaccine (Pandemrix™) was predominantly used. To determine whether the risk of GBS increased after Pandemrix administration, we sought GBS cases during the period of vaccine use from neurologists and a patient support group, and following the vaccination period from hospital episode statistics (HES) in England. We obtained cases’ vaccination histories and illness onset dates from general practitioners. We determined the relative incidence of GBS in the 6 weeks after vaccination using the self-controlled case series method on the cases identified in HES. We included 327 GBS cases, of whom 37 received pandemic vaccine in the study period, nine of whom developed GBS within 6 weeks of vaccination (relative incidence 1.05 [95% confidence interval (CI) 0.37 to 2.24]). We found no evidence of an increased risk of GBS in the 6 weeks following pandemic influenza vaccination.     

The potential effect of temporary immunity as a result of bias associated with healthy users and social determinants on observations of influenza vaccine effectiveness; could unmeasured confounding explain observed links between seasonal influenza vaccine and pandemic H1N1 infection?

ABSTRACT: BACKGROUND: Five observational studies from Canada found an association between seasonal influenza vaccine receipt and increased risk of pandemic influenza H1N1 2009 infection. This association remains unexplained. Although uncontrolled confounding has been suggested as a possible explanation, the nature of such confounding has not been identified. Observational studies of influenza vaccination can be affected by confounding due to healthy users and the influence of social determinants on health. The purpose of this study was to investigate the influence that these two potential confounders may have in combination with temporary immunity, using stratified tables. The hypothesis is that respiratory virus infections may activate a temporary immunity that provides short-term non-specific protection against influenza and that the relationship with being a healthy user or having a social determinant may result in confounding. METHODS: We simulated the effect of confounding on vaccine effectiveness assuming that this could result from both social determinants and healthy user effects as they both influence the risk of seasonal influenza and non-influenza respiratory virus infections as well as the likelihood of being vaccinated. We then examined what impact this may have had on measurement of seasonal influenza vaccine effectiveness against pandemic influenza. RESULTS: In this simulation, failure to adjust for healthy users and social determinants would result in an erroneously increased risk of pandemic influenza infection associated with seasonal influenza vaccination. The effect sizes were not however large. CONCLUSIONS: We found that unmeasured healthy user effects and social determinants could result in an apparent association between seasonal influenza vaccine and pandemic influenza infection by virtue of being related to temporary immunity. Adjustment for social determinants of health and the healthy user effects are required in order to improve the quality of observational studies of influenza vaccine effectiveness.     

Surveillance of perceptions,knowledge, attitudes and behaviors of the Italian adult population (18–69 years) during the 2009–2010 A/H1N1 influenza pandemic

Monitoring perceptions, knowledge, attitudes and behaviors of populations during pandemic flu outbreaks is important as it allows communication strategies to be adjusted to meet emerging needs and assessment to be made of the effects of recommendations for prevention. The ongoing Italian Behavioral Risk Factor Surveillance System (PASSI) offered the setting for investigating people’s opinions and behaviors regarding the A/H1N1 pandemic. PASSI surveillance is carried out in 126/148 Italian Local Health Units (LHU) through monthly telephone interviews administered by public health staff to a random sample of the resident population 18–69 years. In fall 2009 additional questions exploring issues related to the A/H1N1 flu were added to the standard questionnaire. The pandemic module was administered on a voluntary basis by the 70 participating LHUs from November 2nd, 2009 to February 7th, 2010; 4 047 interviews were collected. Overall 33% of respondents considered it likely that they would catch flu, 26% stated they were worried, 16% reported having limited some daily activities out of home and 22% said they would accept vaccination if offered. All these indicators showed a decreasing trend across the four-month period of observation. The most trusted sources of information were family doctors (81%). Willingness to be vaccinated was associated with worry about pandemic, age, sex, having a chronic disease and timing of the interview. The surveillance allowed us to gather relevant information, crucial for devising appropriate public health interventions. In future disease outbreaks, systems monitoring people’s perceptions and behaviors should be included in the preparedness and response plans.