Vaccine hesitancy among hospital staff physicians: A cross-sectional survey in France in 2019

BackgroundHealthcare professionals, because they recommend vaccines to their patients, answer their questions, and vaccinate them, are the cornerstone of vaccination in France. They can nonetheless be affected by vaccine hesitancy (VH). Aims. We sought to study the opinions, practices, and perceptions of French hospital staff physicians (HSPs) toward vaccination and the prevalence and correlates of VH among them. Methods. We conducted a cross-sectional survey in 14 public hospitals in France from September 2018 to October 2019. HSPs completed a standardized questionnaire –most of the time face-to-face — about their vaccine-related attitudes and practices. Data were weighted for age and sex. An agglomerative hierarchical cluster analysis of the HSPs’ perceptions and opinions toward vaccination allowed us to identify vaccine-hesitant HSPs, and multiple Poisson regression with robust standard errors let us study the factors associated with VH. Results. The study included 1,795 HSPs (participation rate: 86%). Almost all (93.7%) were strongly favorable to vaccination, even though 42.2% (95CI = 39.8–44.6) showed moderate VH. VH prevalence was lowest among infectious disease specialists (12.3%; 95CI = 6.7–21.3) and pediatricians (27.7%; 95CI = 21.4–35.2). Hesitant HSPs were less trustful of vaccination information sources and doubted the safety of vaccines more often than HSPs with almost no VH. Compared with non-hesitant HSPs, those with higher VH had less often taken a medical course about vaccination and were less likely to be vaccinated against seasonal influenza, to recommend vaccines to their patients and to try to convince vaccine-hesitant patients to be vaccinated. Conclusions. Strong favorability to vaccination does not prevent VH, which was observed in most specialties. Interventions are required to help hesitant HSPs to adopt more proactive vaccination practices.     

Effectiveness of a multimodal intervention to increase vaccination in obstetrics/gynecology settings

ObjectiveTo test the effectiveness of a multimodal intervention in obstetrics/gynecology (ob-gyn) clinics to increase uptake of influenza and tetanus-diphtheria-acellular pertussis (Tdap) vaccines in pregnant women and these vaccines plus human papillomavirus (HPV) vaccine in non-pregnant women.MethodsA cluster randomized controlled trial among 9 private ob-gyn practices in Colorado from 9/2011 to 5/2014. The intervention consisted of: designation of immunization champions, staff/provider trainings, assistance with vaccine purchasing/management, identification of eligible patients, standing order implementation, chart review/feedback, and patient education materials. Control practices continued usual care. Primary outcomes were receipt of influenza and Tdap vaccines among pregnant women and these vaccines plus HPV vaccine among non-pregnant women, comparing a Baseline period (Year 0/Year 1) to Year 2, intervention versus control. With an estimated sample size of 32,590 per arm, there would be >80% power to detect a 10% difference between groups.ResultsIn the Baseline period, 27% of pregnant women in both intervention and control practices received influenza vaccine. In Year 2, 29% of pregnant women in intervention practices received influenza vaccine versus 41% in control practices. In the Baseline period, 18% of pregnant women in intervention practices received Tdap vaccine versus 22% in control practices. Both intervention and control practices increased to 51% in Year 2, representing an increase of 33% for intervention practices and 29% for control practices, consistent with a change in Tdap recommendations. Relatively few HPV, influenza or Tdap vaccines (≤6% of eligible patients) were given to non-pregnant patients in either intervention or control practices at any time during the study.ConclusionIn this cluster randomized trial designed to increase vaccination uptake, both intervention and control practices showed improved vaccination of pregnant but not non-pregnant patients. Future work should focus on tailoring evidence-based immunization practices or developing new approaches to specifically fit busy ob-gyn offices.     

Development of in ovo-compatible NS1-truncated live attenuated influenza vaccines by modulation of hemagglutinin cleavage and polymerase acidic X frameshifting sites

Emerging avian influenza viruses pose a high risk to poultry production, necessitating the need for more broadly protective vaccines. Live attenuated influenza vaccines offer excellent protective efficacies but their use in poultry farms is discouraged due to safety concerns related to emergence of reassortant viruses. Vaccination of chicken embryos inside eggs (in ovo) induces early immunity in young chicks while reduces the safety concerns related to the use of live vaccines on farms. However, in ovo vaccination using influenza viruses severely affects the egg hatchability. We previously engineered a high interferon-inducing live attenuated influenza vaccine candidate with an enhanced protective efficacy in chickens. Here, we asked whether we could further modify this high interferon-inducing vaccine candidate to develop an in ovo-compatible live attenuated influenza vaccine. We first showed that the enhanced interferon responses induced by the vaccine is not enough to attenuate the virus in ovo. To reduce the pathogenicity of the virus for chicken embryos, we replaced the hemagglutinin cleavage site of the H7 vaccine virus (PENPKTR/GL) with that of the H6-subtype viruses (PQIETR/GL) and disrupted the ribosomal frameshifting site responsible for viral polymerase acidic X protein expression. In ovo vaccination of chickens with up to 10⁵ median egg infectious dose of the modified vaccine had minimal effects on hatchability while protecting the chickens against a heterologous challenge virus at two weeks of age. This study demonstrates that targeted genetic mutations can be applied to further attenuate and enhance the safety of live attenuated influenza vaccines to develop future in ovo vaccines for poultry.     

Healthcare workers’ knowledge,beliefs, and coverage regarding vaccinations in critical care units in Italy

BackgroundLow rates of vaccine coverage have resulted in a resurgence of several vaccine-preventable diseases in many European countries. Routine vaccination of healthcare workers (HCWs) is important to reduce disease transmission, and to promote vaccine awareness and acceptance in the population. The objectives of this cross-sectional study were to investigate knowledge and beliefs about vaccines and to evaluate self-reported immunization coverage with vaccines recommended for HCWs. Additionally, the effects of several factors on these outcomes have been evaluated.MethodsA survey was conducted between September and November 2018 among a random sample of HCWs in cardiac, adult, and neonatal critical care units of 8 randomly selected hospitals across the Campania and Calabria Regions in Italy. Multivariate logistic and linear regression analysis has been performed.ResultsA total 531 HCWs returned the questionnaire for a response rate of 54.9%. Based on a vaccination knowledge score ranging from 0 to 9, more than half of the participants (55.4%) knew few of the vaccines recommended for HCWs (≤3 correct answers), 16.2% knew some vaccines (4–6 correct answers), and 28.4% knew most vaccines (≥7 correct answers), and only 13.2% knew all the vaccines recommended for HCWs. However, two-thirds (62.2%) knew that hepatitis B and influenza vaccines were recommended, and this knowledge was significantly higher among females (p < 0.001), among HCWs aged between 50 and 59 years (p = 0.01) compared with those aged < 30 years, and in those who search for information about recommended vaccines for HCWs (p = 0.012). The vaccine knowledge was significantly lower among nurses and nursing supporting staff compared with physicians (p = 0.032). Approximately two-thirds (62.7%) of HCWs considered themselves at risk of contracting vaccine-preventable infectious diseases during their professional practice. High rates of coverage were self-reported for hepatitis B (96.3%), tetanus and pertussis (93.7%), whereas they were lower for measles/mumps/rubella (80.5%), chickenpox (65.3%), and influenza (35.8%). Only 9.2% of HCWs reported prior receipt of all recommended vaccines. Male HCWs were less likely to report prior receipt of all recommended vaccines (p = 0.011). HCWs aged between 30 and 39 years compared with those aged < 30 years (p = 0.001) and those who knew some (p < 0.001) and most (p = 0.007) of all vaccines recommended for HCWs were more likely to self-report to be immunized.ConclusionsAdditional training about the vaccinations is needed to improve HCWs knowledge and to address specific concerns which may lead to better uptake among this group.     

Barriers and activities to implementing or expanding influenza vaccination programs in low- and middle-income countries: A global survey

IntroductionDespite considerable global burden of influenza, few low- and middle-income countries (LMICs) have national influenza vaccination programs. This report provides a systematic assessment of barriers to and activities that support initiating or expanding influenza vaccination programs from the perspective of in-country public health officials.MethodsPublic health officials in LMICs were sent a web-based survey to provide information on barriers and activities to initiating, expanding, or maintaining national influenza vaccination programs. The survey primarily included Likert-scale questions asking respondents to rank barriers and activities in five categories.ResultsOf 109 eligible countries, 62% participated. Barriers to influenza vaccination programs included lack of data on cost-effectiveness of influenza vaccination programs (87%) and on influenza disease burden (84%), competing health priorities (80%), lack of public perceived risk from influenza (79%), need for better risk communication tools (77%), lack of financial support for influenza vaccine programs (75%), a requirement to use only WHO-prequalified vaccines (62%), and young children require two vaccine doses (60%). Activities for advancing influenza vaccination programs included educating healthcare workers (97%) and decision-makers (91%) on the benefits of influenza vaccination, better estimates of influenza disease burden (91%) and cost of influenza vaccination programs (89%), simplifying vaccine introduction by focusing on selected high-risk groups (82%), developing tools to prioritize target populations (80%), improving availability of influenza diagnostic testing (79%), and developing collaborations with neighboring countries for vaccine procurement (74%) and regulatory approval (73%). Responses varied by country region and income status.ConclusionsLocal governments and key international stakeholders can use the results of this survey to improve influenza vaccination programs in LMICs, which is a critical component of global pandemic preparedness for influenza and other pathogens such as coronaviruses. Additionally, strategies to improve global influenza vaccination coverage should be tailored to country income level and geographic location.     

Knowledge,attitudes, and practices regarding seasonal influenza vaccination during pregnancy in Costa Rica: A mixed-methods study

BackgroundInfluenza increases stillbirth risk, morbidity and mortality in pregnant women. Vaccination protects pregnant women against severe disease and indirectly protects their infants, but coverage among pregnant women remains low worldwide. We aimed to describe knowledge, attitudes, and practices (KAP) regarding seasonal influenza vaccination among postpartum women and prenatal care physicians in Costa Rica.MethodsWe conducted cross-sectional KAP surveys to women one to three days after childbirth at Costa Rican Social Security Fund maternity hospitals, and obstetricians and general practitioners who provided prenatal care in 2017. Principal components analysis, multiple imputation, and logistic regression were used to examine associations between influenza vaccination and demographics, prenatal care, and sources of information—separately for postpartum women and physicians. We also held two focus groups of six healthcare workers each to further describe vaccination KAP.ResultsWe surveyed 642 postpartum women and 146 physicians in maternity hospitals in five Costa Rican provinces of whom 85.5 % (95 % CI: 82.6 %-88.0 %) and 57.9 % (95 % CI: 49.6 %-65.7 %) were vaccinated for influenza, respectively. Factors associated with influenza vaccination for postpartum women included tetanus vaccination (aOR: 3.62, 95 % CI: 1.89–6.92); received vaccination recommendations from clinicians during prenatal check-ups (aOR: 3.39, 95 % CI: 2.06–5.59); had other children in household vaccinated for influenza (aOR: 2.25, 95 % CI: 1.08–4.68); and secondary/university education (aOR: 0.15–0.31) with no formal education as reference. For postpartum women, reasons for vaccination were perceived benefits for mother and infant, whereas not being offered vaccines was most cited for non-vaccination. Most prenatal care physicians recommended influenza vaccines during prenatal check-ups but believed vaccination causes flu-like symptoms.ConclusionVaccination campaigns and provisions of free vaccines effectively increased knowledge and coverage among women in Costa Rica. To improve access, women should be offered vaccines during prenatal care appointments. Educating healthcare workers about vaccine benefits for themselves and patients is needed to mitigate safety concerns.     

Signals and trends of Guillain–Barré syndrome after the introduction of live-attenuated vaccines for influenza in the US and South Korean adverse event reporting systems

BackgroundWith the advent of live-attenuated, quadrivalent, and cell-cultured vaccines for influenza, there have been discussions on the safety of these vaccines compared to conventional vaccines (such as inactivated, trivalent, and egg-cultured vaccines) because of the development of neurological adverse events (AEs). This study aimed to compare the trends and safety signals in the AE reporting systems of the US and South Korea and, more particularly, to evaluate the association between influenza vaccination and Guillain–Barré syndrome (GBS).MethodsIn total, 400,535 AE reports from the US Vaccine Adverse Event Reporting System (VAERS) and 28,766 AE reports from the Korea Adverse Event Reporting System (KAERS) between 2005 and 2017 were assessed. Disproportionality analysis was performed to detect the safety signals and examine the potential risk of GBS with influenza vaccination using the case/non-case approach.ResultsIn both databases, GBS was the most frequently reported AE following influenza immunization. Using the case/non-case approach, the adjusted reporting odds ratio (ROR) of GBS was 3.57 (95% confidence interval [CI], 3.16–4.03) and 3.09 (95% CI, 0.83–11.45) in the VAERS and KAERS data, respectively. People vaccinated with live-attenuated vaccines reported 2.30 times (95% CI, 1.74–3.05) more cases of GBS than those vaccinated with other types of vaccines.ConclusionsOur analysis of the VAERS and KAERS reports for AEs following immunization (AEFI) for influenza shows the need for cautious monitoring regarding the development of GBS after influenza vaccination, particularly, after live-attenuated vaccination. However, owing to potential reporting bias caused by limited AEFI reports after the introduction of new types of influenza vaccines, further prospective safety studies are needed.     

Vaccine exposure during pregnancy among privately and publicly insured women in the United States, 2016–2018

BackgroundVaccine use during pregnancy affects maternal and infant health. Many women do not receive vaccines recommended during pregnancy; conversely, inadvertent exposure to vaccines contraindicated or not recommended during pregnancy may occur. We assessed exposure to two recommended vaccines and two vaccines not recommended during pregnancy among privately and Medicaid-insured women in the United States.MethodsThis study includes a retrospective cohort of pregnancies in women aged 12–55 years resulting in live birth, spontaneous abortion, or stillbirth identified in the IBM® MarketScan® Commercial, Blue Health Intelligence® (BHI®) Commercial, and IBM MarketScan Multi-State Medicaid Databases from August 1, 2016, to December 31, 2018. Gestational age at vaccination was determined using a validated algorithm. We examined vaccines (1) recommended by the Centers for Disease Control and Prevention Advisory Committee on Immunization Practices (ACIP) (tetanus, diphtheria, and acellular pertussis [Tdap]; inactivated influenza) and (2) not recommended (human papillomavirus [HPV]) or contraindicated (measles, mumps, and rubella [MMR]).ResultsWe identified 496,771 (MarketScan Commercial), 858,961 (BHI), and 289,573 (MarketScan Medicaid) pregnancies (approximately 75% aged 20–34 years). Across these three databases, 52.1%, 50.3%, and 31.3% of pregnancies, respectively, received Tdap, most often at a gestational age of 28 weeks, and influenza vaccination occurred in 32.1%, 30.8%, and 18.0% of pregnancies, respectively. HPV vaccination occurred in < 0.2% of pregnancies, mostly in the first trimester among women aged 12–19 years, and MMR was administered in < 0.1% of pregnancies. Use of other contraindicated vaccines per ACIP (e.g., varicella, live attenuated influenza) was rare.ConclusionMaternal vaccination with ACIP-recommended vaccines was suboptimal among privately and Medicaid-insured patients, with lower vaccination coverage among Medicaid-insured pregnancies than their privately insured counterparts. Inadvertent exposure to contraindicated vaccines during pregnancy was rare. This study evaluated only vaccinations reimbursed among insured populations and may have limited generalizability to uninsured populations.     

Surveillance for Guillain-Barré syndrome after influenza vaccination among U.S. Medicare beneficiaries during the 2017–2018 season

BackgroundThe U.S. Food and Drug Administration and the Centers for Medicare & Medicaid Services have been actively monitoring the risk of Guillain-Barré syndrome (GBS) following influenza vaccination among Fee-for-Service (FFS) Medicare beneficiaries every season since 2008. We present our evaluation of the GBS risk following influenza vaccinations during the 2017–2018 season.MethodsWe implemented a multilayered approach to active safety surveillance that included near real-time surveillance early in the season, comparing GBS rates post-vaccination during the 2017–2018 season with rates from five prior seasons using the Updating Sequential Probability Ratio Test (USPRT), and end-of-season self-controlled risk interval (SCRI) analyses.ResultsWe identified approximately 16 million influenza vaccinations. The near real-time surveillance did not signal for a potential 2.5-fold increased GBS risk either in days 8–21 or 1–42 post-influenza vaccination. In the SCRI analyses, we did not detect statistically significant increased GBS risks among influenza-vaccinated Medicare beneficiaries ≥65 years for either the 8–21 or 1–42-day risk windows for all seasonal vaccines combined, high-dose vaccine, or standard-dose vaccines; we did detect an increased GBS risk in days 8–21 post-vaccination for individuals vaccinated with the adjuvanted vaccine (OR: 3.75; 95% CI: 1.01, 13.96), although this finding was not statistically significant after multiplicity adjustment (p = 0.146).ConclusionsOur multilayered surveillance approach—which allows for early detection of elevated GBS risk and provides reliable end-of-season SCRI estimates of effect size—did not identify an increased GBS risk following 2017–2018 influenza vaccinations. The slightly increased GBS risk with the adjuvanted vaccine, which was not statistically significant following multiplicity adjustment, is consistent with the package inserts of all U.S.-licensed influenza vaccines, which warn of a potential low increased GBS risk. The benefits of influenza vaccines in preventing morbidity and mortality heavily outweigh this potential risk.     

Association between health insurance coverage and uptake of seasonal influenza vaccine in Brazos County,Texas

BackgroundLack of health insurance may limit access to influenza vaccination, resulting in higher risk of infection.MethodsThe Brazos County Health Department obtained medical records summarizing vaccination and health insurance status of all influenza cases occurring in December 2017 (n = 417). The odds of influenza vaccination were estimated for those with public or private health insurance as compared to uninsured individuals using multivariate logistic regression analysis adjusted for age and race.ResultsHealth insurance coverage among Brazos County residents with influenza was 62.4%. Public and private health insurance was associated with higher odds of influenza vaccination compared to no insurance (aOR: 2.05; 95% CI: 1.00–4.21 and aOR: 1.77; 95% CI: 1.07–2.92, respectively), particularly among adults 18–64 years of age.ConclusionsInfluenza vaccination is strongly associated with health insurance. Expansion of programs that facilitate access to health services or provide free influenza vaccines may improve influenza prevention among the uninsured.     

Immunogenicity and protection induced by recombinant Toxocara canis proteins in a murine model of toxocariasis

Toxocariasis, a natural helminth infection of dogs and cats caused by Toxocara canis and T. cati, respectively, that are transmitted to mammals, including humans. Infection control is based currently on periodic antihelmintic treatment and there is a need for the development of vaccines to prevent this infection. Materials and Methods: Eight potential vaccine candidate T. canis recombinant proteins were identified by in silico (rTcGPRs, rTcCad, rTcVcan, rTcCyst) and larval proteomics (rTES26, rTES32, rMUC-3 and rCTL-4) analyses. Immunogenicity and protection against infectious challenge for seven of these antigens were determined in a murine model of toxocariasis. C57BL/6 female mice were immunized with each of or combinations of recombinant antigens prior to challenge with 500 T. canis embryonated eggs. Levels of specific antibodies (IgG, IgG1, IgG2a and IgE) in sera and cytokines (IL-5, INF-ɣ and IL-10) produced by antigens-stimulated splenocytes, were measured. Presence of specific antibodies to the molecules was measured in sera of T. canis-seropositive dogs and humans. Results: All seven molecules were immunogenic in immunized mice; all stimulated significantly elevated levels of specific IgG, IgG1 or IgG2a and six were associated with elevated levels of specific IgE; all induced elevated production of IFN- ɣ and IL-10 by splenocytes, but only the in silico-identified membrane-associated recombinants (rTcCad, rTcVcan, and rTcCyst) induced significantly increased IL-5 production. Vaccination with two of the latter (rTcCad and rTcVcan) reduced larval loads in the T. canis challenged mice by 54.3% and 53.9% (P < 0.0001), respectively, compared to unimmunized controls. All seven recombinants were recognized by T. canis-seropositive dog and human sera. Conclusion: The identification of vaccine targets by in silico analysis was an effective strategy to identify immunogenic T. canis proteins capable of reducing larval burdens following challenge with the parasite. Two recombinant proteins, rTcCad and rTcVcan, were identified as promising vaccine candidates for canine toxocariasis.     

Comparison of a frailty short interview to a validated frailty index in adults hospitalized for acute respiratory illness

BackgroundFrailty is an important physiologic factor in studies of influenza and influenza vaccines carried out in older adults and hospitalized populations. Unfortunately, comprehensive assessments of frailty requiring physical assessments and extensive medical record review are not often feasible in time- and resource-limited settings common to studies of influenza and influenza vaccines.MethodsWe developed a 5-question frailty short interview, and implemented it in a multicenter, hospital-based study of influenza over two years. Frailty status defined by the frailty short interview was compared to a validated frailty index based on medical record review of 59 parameters. Agreement between the two frailty measures was assessed, and multivariable linear regression models were used to explore differences between the measures. The association between each frailty measure and likelihood of influenza vaccination was also assessed.ResultsDuring the 2015–2016 and 2016–2017 influenza seasons, 2070 adult patients hospitalized with acute respiratory illness were enrolled and included in analyses. Frailty was frequently identified in the study population; 43% of participants were defined as frail by the frailty short interview and 32% by frailty index. Responses to the frailty short interview were only moderately correlated with the frailty index, and agreement between the two frailty measures was low. Women were more likely to be defined as frail by the frailty short interview than men. White individuals were more likely than other races to be defined as frail by the frailty index. Increasing frailty index was associated with increased likelihood of influenza vaccination, but the frailty short interview was not associated with vaccination.ConclusionsThe frailty short interview provided a feasible and consistent measure of frailty across study hospitals and study years. However, its modest correlation with the frailty index and differential association with likelihood of influenza vaccination highlight differences in the conceptualization of frailty.     

Hepatitis A incidence,seroprevalence, and vaccination decision among MSM in Amsterdam,the Netherlands

BackgroundSeveral outbreaks of Hepatitis A virus (HAV) were recently documented among men who have sex with men (MSM) in Europe. We investigated the HAV incidence among MSM in Amsterdam, the Netherlands; and HAV seroprevalence and HAV vaccination decision among MSM visiting the Sexually Transmitted Infection (STI) clinic in Amsterdam.MethodsUsing surveillance data from 1992 to 2017 of MSM with acute HAV in Amsterdam, we estimated the incidence by calendar year and age. We explored HAV seroprevalence by calendar year and age, determinants for HAV seropositivity, and opting-in/out for HAV vaccination using data collected among MSM that visited the STI clinic between 2006 and 2017 and were included in a nationwide Hepatitis B virus (HBV) vaccination programme. Offering HAV vaccination at the STI clinic differed over three consecutive periods: not offered, offered for free, or offered for 75 euros. Logistic regression analyses were used to explore determinants.ResultsHAV incidence increased in 2016/17 after 4 years of absence and peaked in MSM around 35 years of age. Among MSM visiting the STI clinic, HAV seroprevalence was 37% (95%CI = 35–40%), which was constant over the period 2006–2017, and increased with age (p < 0.001). Determinants for HAV seropositivity in multivariable analysis were: older age (p < 0.001), originating from an HAV endemic country (p < 0.001), and being HBV seropositive (p = 0.001). MSM opted-in more frequently when HAV vaccination was offered for free versus paid (89% versus 11%, respectively; p < 0.001). Younger MSM were less inclined to vaccinate when payment was required (p = 0.010). Post-hoc analyses showed that 98% versus 46% of MSM visiting the Amsterdam STI clinic would be protected against HAV infection if HAV vaccination was offered for free or for 75 euros, respectively.ConclusionsThe MSM population of Amsterdam is vulnerable to a new HAV outbreak. We strongly recommend that MSM have access to free hepatitis A vaccination.     

Importance and value of adjuvanted influenza vaccine in the care of older adults from a European perspective – A systematic review of recently published literature on real-world data

BackgroundThere is an urgent need for improved influenza vaccines especially for older adults due to the presence of immunosenescence. It is therefore highly relevant to compare enhanced influenza vaccines with traditional influenza vaccines with respect to their effectiveness.ObjectiveTo compare vaccine efficacy and effectiveness of adjuvanted influenza vaccines (aTIV/aQIV) vs. non-adjuvanted standard-dose (TIV/QIV) and high-dose (TIV-HD/QIV-HD) influenza vaccines regarding influenza-related outcomes in older adults, complementing findings from the European Centre for Disease Prevention and Control (ECDC)’s systematic review of enhanced seasonal influenza vaccines from February 2020.MethodsA systematic literature search was conducted in Embase and MEDLINE to identify randomised controlled trials, observational studies and systematic reviews, published since ECDC’s systematic review (between 7 February 2020 and 6 September 2021). Included studies were appraised with either the Cochrane Risk of Bias tool, ROBINS-I or AMSTAR 2.ResultsEleven analyses from nine real-world evidence (RWE) studies comprising ～53 million participants and assessing the relative vaccine effectiveness (rVE) of aTIV vs. TIV, QIV and/or TIV-HD in adults aged ≥65 years over the 2006/07–2008/09 and 2011/12–2019/20 influenza seasons were identified. Nine analyses found that aTIV was significantly more effective than TIV and QIV in reducing influenza-related outcomes by clinical setting and suspected influenza outbreaks (rVE ranging from 7.5% to 25.6% for aTIV vs. TIV and 7.1% to 36.3% for aTIV vs. QIV). Seven analyses found similar effectiveness of aTIV vs. TIV-HD in reducing influenza-related medical encounters, inpatient stays and hospitalisations/emergency room visits. In three analyses, aTIV was significantly more effective than TIV-HD in reducing influenza-related medical encounters and office visits (rVE ranging from 6.6% to 16.6%). Risk of bias of identified studies was moderate to high.ConclusionsOur study suggests that both adjuvanted and high-dose vaccines are effective alternatives for vaccination programmes in older adults and preferable over conventional standard-dose vaccines.     

Survey of influenza vaccine knowledge,attitudes, and beliefs among pregnant women in the 2016–17 season

ObjectivesInfluenza vaccination coverage among pregnant women in the United States is suboptimal. We surveyed women who were pregnant during the 2016–17 influenza season to assess knowledge and attitudes regarding influenza vaccination.MethodsWe identified and sampled pregnant women to include approximately equal numbers of vaccinated and unvaccinated women from strata defined by vaccination status and trimester from four integrated health systems in the Vaccine Safety Datalink (VSD). Potential participants were contacted via mail and telephone to complete a standardized survey. Characteristics and responses of women vaccinated and unvaccinated during pregnancy were compared.ResultsThe survey was completed by 510 (48%) of 1062 contacted women; 500 were included in the analysis. Vaccine receipt while pregnant was associated with primigravida status (p = 0.02), college degree (p = 0.01), employment in health care (p < 0.01), and history of routine annual influenza vaccination (p < 0.01). Among 330 vaccinated women, the primary reasons for vaccination included protection of self and baby from influenza (n = 233, 71%), and medical professional recommendation (n = 46, 14%). Multiple reasons were given for nonvaccination, but concern about ‘negative effects’ was cited most often (n = 44, 29%). Vaccinated women were significantly more likely to believe that influenza vaccines are safe and effective, and to recognize the potential for harm from influenza infection. Nearly all women reported receiving at least one influenza vaccination recommendation from a healthcare provider.ConclusionsVaccinated pregnant women were more likely to receive routine annual influenza vaccine compared to those not vaccinated. Recommendations by obstetric providers should be supplemented with efforts to encourage women of childbearing age to receive annual vaccination.     

“The flu… is a little more complicated than a cold”: Knowledge,beliefs, and practices related to influenza and influenza vaccination among at-risk populations and health professionals in Peru

BackgroundInfluenza is a major source of morbidity and mortality with an annual global attack rate estimated at 5–10% in adults and 20–30% in children. Influenza vaccination is the main strategy for reducing influenza-related morbidity and mortality. Like several other countries, Peru has low vaccination coverage, estimated at 25–50% among young children and older adults. Therefore, the study objective was to explore the knowledge, beliefs, attitudes, and practices related to influenza vaccination among populations at higher risk for infection and/or complications and health professionals in Peru, and their perspectives on health communication channels.MethodsThis qualitative study was carried out in three cities. We held nine focus groups with pregnant and postpartum women, parents of young children, and older adults. We carried out 25 in-depth interviews with health professionals (HPs) working in, leading or advising immunization-related programs.ResultsHPs correctly identified the causes of influenza and HPs and at risk community members identified major symptoms. Community members had poor awareness of the potential severity of influenza and were generally unaware of influenza-related mortality. Both HPs and community members greatly underestimated the prevalence of influenza in Peru. HPs in our study overestimated major side effects of the influenza vaccine and community members perceived that the vaccine caused illness. HPs missed important opportunities to promote vaccination in patients with minor illness (runny nose, allergies, colds) and community members did not understand that the vaccine should be received annually.ConclusionsThere is no single strategy that will increase influenza vaccination rates to World Health Organization recommended levels. Instead, it requires multi-faceted commitment from HPs, other healthcare authorities and the government. Addressing important knowledge barriers, specifically negative views regarding the influenza vaccine and the severe morbidity and mortality associated with influenza illness, both in the community and especially among HPs, could have significant impacts.     

Rural,urban, and suburban differences in influenza vaccination coverage among children

Influenza vaccination is the primary way to prevent influenza, yet influenza vaccination coverage remains low in the United States. Previous studies have shown that children residing in rural areas have less access to healthcare and lower vaccination coverage for some vaccines. Influenza vaccination coverage among children 6 months–17 years by rural/urban residence during the 2011–12 through 2018–19 influenza seasons was examined using National Immunization Survey-Flu data. The Council of American Survey Research Organizations response rates for National Immunization Survey-Flu ranged from 48% to 65% (2011–12 through the 2017–18 seasons) for the landline sample and 20%–39% (2011–12 through the 2018–19 seasons) for the cellular telephone sample. Children residing in rural areas had influenza vaccination coverage that ranged from 7.9 (2012–13 season) to 12.6 (2016–17 season) percentage points lower than children residing in urban areas, and ranged from 4.5 (2012–13 season) to 7.4 (2016–17 season) percentage points lower than children residing in suburban areas. The differences in influenza vaccination coverage among rural, suburban, and urban children were consistent over the eight seasons studied. Lower influenza vaccination coverage was observed among rural children regardless of child’s age, mother’s education, household income, or number of children under 18 years of age in the household. Rural versus urban and suburban differences in influenza vaccination coverage remained statistically significant while adjusting for selected sociodemographic characteristics. A better understanding of the reasons for lower childhood influenza vaccination coverage for children in rural and suburban areas is needed.     

Influenza vaccination coverage among persons seeking outpatient medical care for acute respiratory illness in five states in the United States, 2011–2012 through 2018–2019

BackgroundIn the United States (U.S.), annual influenza vaccination has been recommended for all persons aged ≥6 months with the Healthy People 2020 coverage target of 70%. However, vaccination coverage has remained around 42–49% during the past eight influenza seasons. We sought to quantify influenza vaccination coverage and factors associated with vaccination in persons seeking outpatient medical care for an acute respiratory illness (ARI).MethodsWe enrolled outpatients aged ≥6 months with ARI from >50 U.S. clinics from 2011 to 2012 through 2018–2019 influenza seasons and tested for influenza with molecular assays. Vaccination status was based on documented receipt of the current season’s influenza vaccine. We estimated vaccination coverage among influenza-negative study participants by study site, age, and season, and compared to state-level influenza coverage estimates in the general population based on annual immunization surveys. We used multivariable logistic regression to examine factors independently associated with receipt of influenza vaccines.ResultsWe enrolled 45,424 study participants with ARI who tested negative for influenza during the study period. Annual vaccination coverage among influenza-negative ARI patients and the general population in the participating states averaged 55% (range: 47–62%), and 52% (range: 46–54%), respectively. Among enrollees, coverage was highest among adults aged ≥65 years (82%; range, 80–85%) and lowest among adolescents aged 13–17 years (38%; range, 35–41%). Factors significantly associated with non-vaccination included non-White race, no college degree, exposure to cigarette smoke, absence of high-risk conditions, and not receiving prior season influenza vaccine.ConclusionsInfluenza vaccination coverage over eight seasons among outpatients with non-influenza respiratory illness was slightly higher than coverage in the general population but 15% lower than national targets. Increased efforts to promote vaccination especially in groups with lower coverage are warranted to attain optimal health benefits of influenza vaccine.