Barriers of Influenza Vaccination Intention and Behavior - A Systematic Review of Influenza Vaccine Hesitancy, 2005 - 2016.

Influenza is one of the most widespread respiratory infections and poses a huge burden on health care worldwide. Vaccination is key to preventing and controlling influenza. Influenza vaccine hesitancy is an important reason for the low vaccination rate. In 2019, Vaccine hesitancy was identified as one of the top 10 threats to global health by the World Health Organization. However, there remains a glaring scarcity of bibliometric research in that regard. This study sought to identify research hotspots and future development trends on influenza vaccine hesitation and provide a new perspective and reference for future research. We retrieved publications on global influenza vaccine hesitancy from the Web of Science Core Collection database, Scopus, and PubMed databases from inception to 2022. This study used VOSviewer and CiteSpace for visualization analysis. Influenza vaccine hesitancy-related publications increased rapidly from 2012 and peaked in 2022. One hundred and ninecountries contributed to influenza vaccine hesitation research, and the United States ranked first with 541 articles and 7161 citations. Vaccines-Basel was the journal with the largest number of published studies on influenza vaccine hesitations. MacDonald was the most frequently cited author. The most popular research topics on influenza vaccine hesitancy were (1) determinants of influenza vaccination in specific populations, such as healthcare workers, children, pregnant women, and so on; (2) influenza and COVID-19 vaccine hesitancy during the COVID-19 pandemic. The trend in the number of annual publications related to influenza vaccine hesitancy indicating the COVID-19 pandemic will prompt researchers to increase their attention to influenza vaccine hesitancy. With healthcare workers as the key, reducing vaccine hesitancy and improving vaccine acceptance in high-risk groups will be the research direction in the next few years.

BackgroundSeasonal influenza can circulate in parallel with coronavirus disease (COVID-19) in winter. In the context of COVID-19 pandemic, the risk of co-infection and the burden it poses on healthcare system calls for timely influenza vaccination among pregnant women, who are the priority population recommended for vaccination. We aimed to evaluate the acceptance of influenza vaccination and associated factors among pregnant women during COVID-19 pandemic, provide evidence to improve influenza vaccination among pregnant women, help reduce the risk of infection and alleviate the burden of healthcare system for co-infected patients.MethodsWe conducted a multi-center cross-sectional study among pregnant women in China. Sociodemographic characteristics, health status, knowledge on influenza, attitude towards vaccination, and health beliefs were collected. Locally weighted scatterplot smoothing regression analysis was used to evaluate the trends in the acceptance of influenza vaccine. Logistic regression was applied to identify factors associated with vaccination acceptance.ResultsThe total acceptance rate was 76.5% (95%CI: 74.8–78.1%) among 2568 pregnant women enrolled. Only 8.3% of the participants had a history of seasonal influenza vaccination. In the logistic regression model, factors associated with the acceptance of influenza vaccine were western region, history of influenza vaccination, high knowledge of influenza infection and vaccination, high level of perceived susceptibility, perceived benefit, cues to action and low level of perceived barriers. Among 23.5% of the participants who had vaccine hesitancy, 48.0% of them were worried about side effect, 35.6% of them lacked confidence of vaccine safety.ConclusionsOur findings highlighted that tailored strategies and publicity for influenza vaccination in the context of COVID-19 pandemic are warranted to reduce pregnant women’s concerns, improve their knowledge, expand vaccine uptake and alleviate pressure for healthcare system.

Background: Influenza could circulate in parallel with COVID-19. Studies focusing on the comparison of vaccine acceptance between COVID-19 and seasonal influenza are lacking. The aim of the study was to assess and compare vaccine acceptance of COVID-19 and influenza among reproductive women in China, in order to better understand and address factors associated with vaccine acceptance and to provide guidance for targeted measures to promote vaccination.Methods: A national anonymous cross-sectional survey on COVID-19 and influenza vaccine acceptance among reproductive women aged 18–49 years in China was conducted online based on health belief model, a model widely used to evaluate health beliefs. Sociodemographic characteristics, health status, knowledge, attitude, and health beliefs related to COVID-19 and influenza infection and vaccination were retrieved. Pearson's χ2 test was used to compare the vaccine acceptance by the factors mentioned above. Multivariable logistic regression was used to assess the adjusted associations of factors related to vaccine acceptance. Paired t-test was used to compare scores of health beliefs between influenza and COVID-19 vaccinations.Results: COVID-19 vaccine acceptance rate among reproductive women was 90.3% (95% CI 89.2–91.3%), which was significantly higher than influenza vaccine acceptance rate (85.5%, 95% CI: 84.2–86.7%). Influenza and COVID-19 vaccine acceptance both had the trends to decrease with age (all p < 0.05). Living in the western region, young age, a high level of knowledge scores on disease and vaccines, a high level of perceived susceptibility, a high level of cues to action, and a low level of perceived barriers were positively associated with both COVID-19 and influenza vaccine acceptance (all p < 0.05), while influenza vaccination history was additionally associated with influenza vaccine acceptance (p < 0.05).Conclusions: Our findings suggest that tailored public health measures are needed to improve reproductive women's knowledge of COVID-19, influenza, and vaccines to alleviate women's vaccine hesitancy and expand vaccine uptake.

BACKGROUND AND OBJECTIVESMedia attention on 2009 H1N1 vaccination has been negative. Information on the willingness of health care workers (HCWs) to accept vaccination against the 2009 pandemic influenza is sparse. Thus, we undertook this study to investigate the attitude of HCWs toward this vaccine and possible factors associated with vaccine acceptance.DESIGN AND SETTINGCross-sectional observational study of HCWs conducted at Saudi Aramco Medical Services Organization (SAMSO) in February 2009.PATIENTS AND METHODSA self-administered questionnaire was distributed to 250 individuals and 161 (64.4%) were completed.RESULTSOf the total respondents, 66 (41%) were Arab, 55 (34.2%) were Asian/Far East, and 40 (24.8%) were of other nationalities. A total of 65 (40.4%) responses were from physicians and nurses, and 96 (59.6%) were from other HCWs. Of all the responders, 152 (94.4%) were aware of the H1N1 influenza situation, and 135 (83.9%) stated they had received enough information about the current situation. Of all the respondents, 59 (36.6%) stated that they received the seasonal influenza vaccination in 2008–2009, and 50 (31.1%) expressed their willingness to take the 2009 H1N1 vaccine. A total of 24 (14.9%) stated that the vaccine contains thiomersal, 21 (13%) stated that the vaccine contains adjuvants, 19 (11.8%) stated it contains squalene, 17 (10.6%) thought the vaccine causes infertility, and 29 (18%) thought the vaccine causes Guillain-Barré syndrome. In a multivariate analysis, the following factors were noted to be important in choosing to be vaccinated: being Asian, not being a doctor or a nurse, and previous acceptance of the seasonal influenza vaccine (P≤.01).CONCLUSIONSThe acceptance of the current 2009 pandemic H1N1 vaccine was low. Important factors associated with the increasing H1N1 influenza vaccine acceptance include being Asian, not being a doctor or a nurse, and previous acceptance of the seasonal influenza vaccine.

Context：Children have very high morbidity and hospitalization rates from seasonal and pandemic influenza. They also play a major role in the spread of influenza disease. It has been reported conventional (non-adjuvanted) inactivated influenza vaccines have low efficacy, while MF59-adjuvanted vaccines could be more efficient than conventional vaccines. But the immunogenicity and safety of MF59-adjuvanted vaccines in children have not been well established. So the objectives of this study are to examine immunogenicity and safety of MF59-adjuvanted seasonal influenza and pandemic influenza A (H1N1) vaccines in children and assess whether MF59-adjuvanted influenza vaccine is better than non-adjuvanted vaccine.&#13;\n&#13;\nMethods: A comprehensive search of PubMed, MEDLINE and Cochrane Library was performed without time and language restrictions. Randomized clinical trials, which assess immunogenicity and/or safety of MF59 adjuvanted seasonal influenza vaccine and pandemic influenza A (H1N1) vaccine in children, were identified. The quality of these selected studies was evaluated using Jadad Score and Cochrane Handbook of Systematic Reviews of Interventions. The criteria of seroprotection rate (SPR), seroconversion rate (SCR) and Geometric mean titer ratio (GMTR) implemented by the European Committee for Medicinal Products for Human Use (CHMP) was used as the standard criteria to evaluate immunogenicity of vaccines.&#13;\n&#13;\nResults: 12 studies were identified in total, 5 on MF59-adjuvanted trivalent seasonal influenza vaccines, 1 on MF59-adjuvanted monovalent H3N2 influenza vaccines and 6 on MF59-adjuvanted pandemic H1N1 influenza vaccines. Immunogenicity: For MF59-adjuvanted influenza vaccines, immunogenecity of homologous strains in terms of influenza H1N1, H3N2 can meet all three criteria of CHMP after the first dose in all age cohorts (SPR [77, 100], SCR [43, 100] and GMTR [7, 41]), whereas a second dose was needed for B antigen. For non-adjuvanted influenza vaccines, a second dose was needed for all three strains to meet all the criteria (GMTR [3.95, 97], SPR [70, 100] and SCR [42, 99]), with the exceptions of three trials related to B strain. When it comes to heterologous strains, a second dose was needed for both MF59-adjuvanted trivalent seasonal influenza and non-adjuvanted trivalent seasonal vaccines. However, MF59-adjuvanted vaccine can induce greater immune responses especially for B strain after the second dose (SPR [71, 100], GMTR [3.35, 16] and SCR [55, 96]), while the immunogenicity for non-adjuvanted vaccine was still poor with 7 out of 11 trials cannot meet all three criteria of CHMP.&#13;\n&#13;\nSafety: MF59-adjuvanted influenza vaccines often induced mild and transient reactions.&#13;\nConclusions: MF59-adjuvanted seasonal influenza vaccine and pandemic influenza A (H1N1) vaccine have good immunogenicity and safety profile, and MF59-adjuvanted influenza vaccine is better than non-adjuvanted influenza vaccine in terms of immunogenicity, whether it is trivalent vaccine or monovalent vaccine.

Single-dose influenza vaccination of patients with egg allergy in a multicenter study

Exploring determinants of acceptance of the pandemic influenza A (H1N1) 2009 vaccination in nurses

Safety of influenza vaccines in pregnant women

BackgroundInfluenza vaccine is recommended for all children ≥6 months, yet uptake is suboptimal. We aimed to quantify child influenza vaccine coverage and identify factors associated with influenza vaccine hesitancy (VH) before and during the COVID-19 pandemic.MethodsWe conducted a prospective, repeated cross-sectional assessment in English and Spanish of caregiver influenza knowledge, attitudes, behaviors, and associated VH among hospitalized children 6 months through 18 years at a large pediatric medical institution. Caregivers were enrolled 4-5 days per week, between 12/11/2019--1/31/2020 and 12/8/2020--4/5/2021. VH was assessed using the Parent Attitudes about Childhood Vaccines (PACV) survey; PACV score ≥50 denoted VH. Descriptive statistics and multivariable logistic regression were used.ResultsDuring 2019-2020 and 2020-2021 influenza seasons, 269/282 (95%) and 295/307 (96%) of approached caregivers enrolled, respectively. By caregiver report, 94% of children in 2019-2020 and 91% in 2020-2021 were up-to-date with routine childhood vaccines (p=0.13). Specific to influenza vaccine, 73% and 68% of children received or planned to receive influenza vaccine in 2019-2020 and 2020-2021, respectively (p=0.13). Based on PACV score, 13% of parents were VH in 2019-2020 compared with 17% in 2020-2021 (p=0.24; Figure 1). Caregivers who had not/did not intend to vaccinate their children had a higher family income (71% vs. 57% >&30,000, p< 0.01) and were less likely to be Hispanic/Latino (35% vs. 47%, p=0.02). 77% of caregivers were satisfied with information about influenza vaccine received from healthcare providers. Overall, 36% believed “you can get the flu from the flu shot.” In 2020-2021, caregivers were less likely to believe that “flu can be a dangerous infection in children,” to be “scared of my child getting the flu” and to agree that “all children over 6 months of age should receive the flu shot every year” (Table 1).Table 1. Caregiver knowledge and attitudes about seasonal influenza vaccine, 2019-20 versus 2020-21Figure 1. Influenza vaccine uptake by PACV score during 2019-2020 (a) and 2020-2021 (b) seasonsConclusionDuring the COVID-19 pandemic, caregivers of hospitalized children were less concerned about influenza than pre-pandemic and misinformation about influenza and influenza vaccine persisted. Increased efforts may be needed to educate caregivers about the importance of influenza immunization during the 2021-22 season.DisclosuresC. Mary Healy, MD, Dexcom (Shareholder)Intuitive (Shareholder)Quidel Corporation (Shareholder)Up to Date (Other Financial or Material Support, Honorarium)Vapotherm (Shareholder)

Influenza vaccine acceptance and hesitancy among adults hospitalized with severe acute respiratory illnesses, United States 2019–2020

Vaccination to prevent influenza virus infection and to lessen its severity is recommended among healthcare workers (HCWs). Health professionals have a higher risk of exposure to viruses and could transmit the influenza virus to vulnerable patients who are prone to severe disease and mortality. The aim of the current study was to evaluate the levels of influenza vaccine acceptance and uptake as well as its determinants, among Jordanian HCWs over the last influenza season of 2021/2022. This study was based on a self-administered electronic survey that was distributed in March 2022. Psychological determinants of influenza vaccine acceptance and vaccine conspiracy beliefs were assessed using the previously validated 5C scale questionnaire (confidence, complacency, constraints, calculation and collective responsibility) and the vaccine conspiracy beliefs scale. The study sample comprised a total of 1218 HCWs: nurses (n = 412, 33.8%), physicians (n = 367, 30.1%), medical technicians (n = 182, 14.9%), pharmacists (n = 161, 13.2%) and dentists (n = 87, 7.1%), among others. About two-thirds of the study sample expressed willingness to receive influenza vaccination if provided free of charge (n = 807, 66.3%), whereas less than one-third were willing to pay for the vaccine (n = 388, 31.9%). The self-reported uptake of the influenza vaccine in the last influenza season was 62.8%. The following factors were significantly associated with higher acceptance of influenza vaccination if provided freely, as opposed to vaccine hesitancy/rejection: male sex; physicians and dentists among HCW categories; higher confidence and collective responsibility; and lower complacency, constraints and calculation. Higher influenza vaccine uptake was significantly correlated with nurses and physicians among HCW categories, older age, a higher monthly income, higher confidence and collective responsibility, lower complacency and constraints and lower embrace of general vaccine conspiracy beliefs. The results of the current study can provide helpful clues to improve influenza vaccine coverage among HCWs in Jordan. Consequently, this can help to protect vulnerable patient groups and reserve valuable resources in healthcare settings. Psychological determinants appeared to be the most significant factors for vaccine acceptance and uptake, whereas the embrace of general vaccine conspiracy beliefs was associated with lower rates of influenza vaccine uptake, which should be considered in educational and interventional measures aiming to promote influenza vaccination.

Background: Influenza continues to be a significant factor contributing to disease and mortality. Despite the availability of influenza vaccines, the persistently high levels of vaccine hesitancy remain a cause for concern. Objectives: This study aims to evaluate influenza vaccine hesitancy and assess knowledge about influenza vaccination among medical students. Materials and Methods: A cross-sectional survey was conducted between September 1, 2023 and September 15, 2023, involving both preclinical and clinical medical students at Diyala University’s College of Medicine in Iraq. Data collection utilized an online, self-administered questionnaire, and data analysis was performed using SPSS version 16. Statistical significance was determined at a threshold of P &lt; 0.05. Results: The study included a total of 158 participants, consisting of 83 premedical students (52.5%) and 75 clinical students (47.5%). The mean age of the participants was 21.5 years (±7.3). The majority of respondents were female (61.4%), nonsmokers (89.2%), had received the COVID-19 vaccine (91.8%), and had not received the influenza vaccine (86.7%). Alarmingly, more than half of the participants (53.2%) expressed hesitancy toward receiving the influenza vaccine. In addition, the study revealed that clinical students had a better understanding of influenza vaccine-related information. The multiple logistic regression analysis identified several predictor variables associated with vaccine hesitancy, including female gender (odds ratio [OR]: 4.501, P &lt; 0.001, confidence interval [CI]: 2.541–5.386), preclinical student status (OR: 3.565, P &lt; 0.001, CI: 2.226–4.040), nonsmoking status (OR: 2.721, P = 0.010, CI: 1.605–3.601), and lack of prior influenza vaccination (OR: 2.107, P = 0.003, CI: 1.903–3.466). These variables collectively explained 49.7% of the variance in vaccine hesitancy. Conclusions: Vaccine hesitancy was notably higher among preclinical medical students. Identifying the reasons for vaccine acceptance and refusal can inform strategies to enhance vaccination uptake among healthcare providers and the general population.

Background/objective Annual influenza vaccination is recommended for all healthcare workers because of their increased risk of nosocomial infections. Despite the recognized benefits, there is public concern about vaccination against many diseases, often termed vaccine hesitancy. As a result, influenza vaccination coverage in all European countries, including the Netherlands, is below the 75% recommended by the WHO and the European Union, which poses a threat to public health. With this in mind, this study aimed to gain insights into influenza vaccine uptake among healthcare workers of a university hospital in Amsterdam. Methods Eighteen semi-structured interviews were conducted with healthcare workers of the Amsterdam UMC with an average duration of 30 minutes. The transcripts were coded and analyzed based on the 5C vaccine hesitancy model. Results Half of the participants reported a low risk perception regarding influenza. Furthermore, non-pharmaceutical measures were more frequently mentioned than influenza vaccination, indicating that many do not see vaccination as essential. Although all participants were aware of occupational transmission and recognized the indirect protection vaccination provides for patients, they were less aware of asymptomatic transmission. Additionally, the limited availability of dates, timeslots and the need for appointments hindered participants' access to vaccination. Conclusion This study provides insights into the perceptions of influenza vaccination among healthcare workers, identifying key barriers and facilitators to uptake. To increase influenza vaccination coverage, hospitals can focus on improving information provision and reducing barriers to accessing vaccines.

The present study aimed to assess influenza vaccine hesitancy and vaccine literacy levels among youth and adults in China, as well as the association between them. An online cross-sectional survey was conducted in Mainland China. Participants' total vaccine literacy and three sub-dimension vaccine literacy (knowledge literacy, competence literacy, and decision-making literacy) were assessed by a validated vaccine literacy scale. Having received influenza vaccination in the past three years or intending to accept it in next influenza season indicates less influenza vaccine hesitancy. Among 997 participants, a sub-optimal vaccine literacy was observed, with a mean score of 66.83 ± 10.27. Regression models 1-4 revealed that participants with middle (aOR: 1.431, P=0.039, 95% CI: 1.018~2.010) or high (aOR: 1.651, P=0.006, 95% CI: 1.157~2.354) total vaccine literacy, as well as those with high competence literacy (aOR: 1.533, P=0.017, 95% CI: 1.079~2.180), or high decision-making literacy (aOR: 1.822, P=0.001, 95% CI: 1.261~2.632) were more likely to have been vaccinated against influenza at least once in past three years. However, those with a high knowledge literacy were associated with a lower influenza vaccine rate (aOR: 0.676, P=0.046, 95% CI: 0.460~0.994). Regression models 5-8 revealed that participants with middle (aOR: 1.661, P=0.008, 95% CI: 1.142~2.414) or high total vaccine literacy (aOR: 2.645, P=0.000, 95% CI: 1.774~3.942), as well as those with middle (aOR: 1.703, P=0.005, 95% CI: 1.177~2.464) or high competence literacy (aOR: 2.346, P=0.000, 95% CI: 1.159~3.461), or high decision-making literacy (aOR: 2.294, P=0.000, 95% CI: 1.531~3.436) were more likely to express the willingness to receive the influenza vaccine in the next influenza season. The participants' influenza vaccine hesitancy was negatively associated with their total vaccine literacy levels and two of the three sub-dimensions: competence literacy and decision-making literacy. Knowledge literacy suggested a positive or no relationship with influenza vaccine hesitancy.

Seasonal Influenza Vaccine Hesitancy Profiles and Determinants Among Chinese Children's Guardians and the Elderly