Determinants of seasonal influenza vaccination in pregnant women in Valencia, Spain

Mathematical modeling for estimating influenza vaccine efficacy: A case study of the Valencian Community, Spain

Vaccine efficacy and its quantification is a crucial concept for the proper design of public health vaccination policies. In this work we proposed a mathematical model to estimate the efficacy of the influenza vaccine in a real-word scenario. In particular, our model is a SEIR-type epidemiological model, which distinguishes vaccinated and unvaccinated populations. Mathematically, its dynamics is governed by a nonlinear system of ordinary differential equations, where the non-linearity arises from the effective contacts between susceptible and infected individuals. Two key aspects of this study is that we use a vaccine distribution over time that is based on real data specific to the elderly people in the Valencian Community and the calibration process takes into account that over one influenza season a specific proportion of the population becomes infected with influenza. To consider the effectiveness of the vaccine, the model incorporates a parameter, the vaccine attenuation factor, which is related with the vaccine efficacy against the influenza virus. With this framework, in order to calibrate the model parameters and to obtain an influenza vaccine efficacy estimation, we considered the 2016-2017 influenza season in the Valencian Community, Spain, using the influenza reported cases of vaccinated and unvaccinated. In order to ensure the model identifiability, we choose to deterministically calibrate the parameters for different scenarios and we find the one with the minimum error in order to determine the vaccine efficacy. The calibration results suggest that the influenza vaccine developed for 2016-2017 influenza season has an efficacy of approximately 76.7%, and that the risk of becoming infected is five times higher for an unvaccinated individual in comparison with a vaccinated one. This estimation partially agrees with some previous studies related to the influenza vaccine. This study presents a new integrated mathematical approach to study the influenza vaccine efficacy and gives further insight into this important public health topic.

Vaccination coverage during pregnancy and factors associated with refusal of recommended vaccinations: An Italian cross sectional study

Background

The vaccines recommended during pregnancy are the Tdap, the influenza vaccine, and, during the SARS-CoV-2 pandemic, the vaccine against COVID-19. This survey aimed at determining vaccination coverage among pregnant women and adverse events, reasons for vaccine refusal, and factors associated with vaccine uptake.

Methods

A single-center cross-sectional study was conducted on women who delivered between March and April 2022 at Careggi University Hospital in Florence, Italy. Information on the vaccinations (Tdap, influenza and COVID-19) received during pregnancy were collected through in-person interviews.

Results

Among 307 enrolled women (response rate 99 % on a study population of 310 eligible women), 74 % of patients were vaccinated with Tdap, 82 % against COVID-19, and only 33 % against influenza. Vaccination coverage for Tdap and COVID-19 was significantly higher among Italian than foreign patients (80 % vs 51 %, p < 0.001 and 86 % vs 69 %, p = 0.002, respectively), and for Tdap was higher among patients followed in the private vs public care setting. The main reasons behind refusal of vaccinations were low risk perception of influenza (41 %), insufficient information received from the prenatal care provider regarding the Tdap (35 %), and, for the COVID-19, fear of vaccine side effects (64 %), and concerns about effects on the fetus (70 %).

Conclusions

Adherence to the influenza vaccine was low because of reduced perception of the disease risks. The difference in vaccination coverage between Italians and foreigners is an example of healthcare disparity. Better information provided to patients about vaccines' efficacy and safety is advisable to increase acceptance of recommended vaccines.

Barriers and facilitators of vaccine hesitancy for COVID-19, influenza, and pertussis during pregnancy and in mothers of infants under two years: An umbrella review

BACKGROUND

Vaccination during pregnancy has been repeatedly demonstrated to be safe and effective in protecting against infection and associated harms for the mother, developing baby, and subsequent infant. However, maternal vaccination uptake remains low compared to the general population.

OBJECTIVES

An umbrella review to explore the barriers and facilitators to Influenza, Pertussis and COVID-19 vaccination during pregnancy and within 2 years after childbirth, and to inform interventions to encourage uptake (PROSPERO registration number: CRD42022327624).

METHODS

Ten databases were searched for systematic reviews published between 2009 and April 2022 exploring the predictors of vaccination or effectiveness of interventions to improve vaccination for Pertussis, Influenza, or COVD-19. Both pregnant women and mothers of infants under two years were included. Barriers and facilitators were organised using the WHO model of determinants of vaccine hesitancy through narrative synthesis, the Joanna Briggs Institute checklist assessed review quality, and the degree of overlap of primary studies was calculated.

RESULTS

19 reviews were included. Considerable overlap was found especially for intervention reviews, and the quality of the included reviews and their primary studies varied. Sociodemographic factors were specifically researched in the context of COVID-19, exerting a small but consistent effect on vaccination. Concerns around the safety of vaccination particularly for the developing baby were a main barrier. While key facilitators included recommendation from a healthcare professional, previous vaccination, knowledge around vaccination, and communication with and support from social groups. Intervention reviews indicated multi-component interventions involving human interaction to be most effective.

CONCLUSION

The main barriers and facilitators for Influenza, Pertussis and COVID-19 vaccination have been identified and constitute the foundation for policy development at the international level. Ethnicity, socioeconomic status, concerns about vaccine safety and side effects, and lack of healthcare professionals' recommendations, are the most relevant factors of vaccine hesitancy. Adapting educational interventions to specific populations, person-to-person interaction, healthcare professionals' involvement, and interpersonal support are important strategies to improve uptake.

Knowledge, Perceptions, Attitudes and Practices of Midwives Regarding Maternal Influenza and Pertussis Vaccination: A Qualitative Study

The coverage of maternal vaccination against pertussis and, particularly, influenza is lower than expected. The lack of recommendation from healthcare providers conditions non-vaccination in pregnant women. The purpose was to determine the knowledge, perceptions, attitudes and practices of midwives regarding maternal influenza and pertussis vaccination. A qualitative descriptive study based on semi-structured, face-to-face interviews with seventeen midwives was conducted, including purposive sampling and thematic analyses. Midwives had disparate knowledge and perceptions about the severity of influenza and pertussis in pregnant women, and influenza was not considered very serious. The vaccines were generally considered safe. However, because midwives did not have enough information about the safety of the influenza vaccine, there was a tendency not to recommend it. While most midwives had a positive attitude toward vaccination, their advocation for vaccination against influenza was not as clear as it was for pertussis. Not wanting to influence the decision and assuming an informative–facilitating role also led providers to recommend the influenza vaccine less frequently. Midwives are among the main sources of professional advice for pregnant women. Addressing their understanding and professional practices regarding maternal vaccination is key to change the attitude of pregnant women and thus increase vaccine uptake among them, particularly for influenza.

Vaccination in pregnancy against pertussis and seasonal influenza: key learnings and components from high-performing vaccine programmes in three countries: the United Kingdom, the United States and Spain

BACKGROUND

Pertussis and seasonal influenza are responsible for significant maternal, neonatal, and infant morbidity and mortality, but vaccine coverage rates (VCR) for both pertussis (administered as a tetanus, diphtheria, acellular pertussis [Tdap] vaccination) and seasonal influenza in pregnancy remain generally low. Only a small number of countries, including Spain, the United Kingdom (UK), and the United States (US), have high Tdap and seasonal influenza VCRs in pregnancy. The purpose of this study was to identify the key factors that contributed to the high VCRs observed in these countries.

METHODS

The experience from both Tdap and seasonal influenza vaccination programmes during pregnancy were documented in Spain, the UK, and the US using a three-step approach. A literature review yielded 157 publications, and a further 117 documents were selected through desk research. A published five-pillar VCR framework for influenza was amended to evaluate the specific contributing factors leading to high Tdap and seasonal influenza VCRs among pregnant women.

RESULTS

The analysis identified components that contributed to higher VCR in pregnant women across three different healthcare systems in Spain, UK, and US. The combination of several key interventions in each country led to a rapid increase in VCR that reached near-optimal levels (i.e. 75% for seasonal influenza) within a few years. As well as inclusion in national immunisation programme and vaccine reimbursement, key components that were identified included the mobilisation of health authorities, prenatal care Healthcare Professionals (HCP) and scientific societies, the inclusion of vaccination in antenatal medical guidance, the provision of educational material to HCPs, and a strong disease awareness driven by recent pertussis outbreaks in each country.

CONCLUSIONS

Although there is no simple, universal solution to improving sub-optimal VCRs, the list of components identified in this study from three countries with high-performing Tdap and seasonal influenza vaccination programmes provides a basis for public health and medical stakeholders in other countries to define strategies to successfully implement national vaccination programmes for pregnant women.

Determinants of influenza vaccine hesitancy among pregnant women in Europe: a systematic review

BACKGROUND

Pregnant women are at high risk for severe influenza. However, maternal influenza vaccination uptake in most World Health Organization (WHO) European Region countries remains low, despite the presence of widespread national recommendations. An influenza vaccination reduces influenza-associated morbidity and mortality in pregnancy, as well as providing newborns with protection in their first months. Potential determinants of vaccine hesitancy need to be identified to develop strategies that can increase vaccine acceptance and uptake among pregnant women. The primary objective of the systematic review is to identify the individual determinants of influenza vaccine hesitancy among pregnant women in Europe, and how to overcome the hesitancy.

METHODS

Databases were searched for peer-reviewed qualitative and quantitative studies published between 2009 and 2019 inclusive. Databases included PubMed via MEDLINE, Cochrane Central Register for Controlled Trials, PsycINFO, SAGE Journals, Taylor and Francis and Springer nature. These covered themes including psychology, medicine, and public health. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach, 11 studies were eligible and analyzed for significant determinants of influenza vaccine hesitancy among pregnant women in Europe.

RESULTS

The most commonly reported factors were psychological aspects, for example concerns about safety and risks to mother and child, or general low risk perception of becoming ill from influenza. Doubts about the effectiveness of the vaccine and a lack of knowledge about this topic were further factors. There was also influence of contextual factors, such as healthcare workers not providing adequate knowledge about the influenza vaccine or the pregnant lady stating their antivaccine sentiment.

CONCLUSION

Health promotion that specifically increases knowledge among pregnant women about influenza and vaccination is important, supporting a valid risk judgment by the pregnant lady. The development of new information strategies for dialogue between healthcare providers and pregnant women should form part of this strategy.

'My primary purpose is to protect the unborn child': Understanding pregnant women's perceptions of maternal vaccination and vaccine trials in Europe

Despite the important benefits of maternal vaccination for pregnant women and newborns, vaccination uptake is low in many European countries. Differences in vaccination policies and recommendations, as well as concerns about vaccine safety can partly explain inadequate coverage rates and women's hesitancy to get vaccinated during pregnancy. This study aims to explore pregnant women's experiences, decision-making processes and perceptions towards maternal vaccination and maternal vaccine trials in France, Germany, Italy, Spain and the United Kingdom. Qualitative interviews and focus groups were conducted with 258 pregnant women identified through local research panels and snowballing. Topic guides translated in local languages were designed to explore women's awareness and perceptions of maternal vaccination, and willingness to participate in vaccine trials during pregnancy. A thematic analysis was conducted. Pregnant women were found to have low awareness about maternal vaccination, with many reporting not having received a recommendation to vaccinate from their doctors. Strong trust in health professionals indicate that strengthened recommendations could improve vaccination uptake. Vaccination decision-making in pregnancy was described in the context of a highly emotional period, generating anxiety and fears around the safety of vaccines. Pregnancy was also discussed as a period during which women develop nurturing and protective identities. However, depending on the information they received as well as influences from experts, families and peers, women either perceived vaccination as a threat to their babies' safety or as a means to protect them. Attitudes towards maternal vaccine trials were less ambiguous, with most pregnant women strongly rejecting the notion of taking part in trials. While strategies to improve pregnant women's awareness and perceptions of maternal vaccination are needed, it is equally important to understand why healthcare professionals may not be recommending vaccination. More coordinated strategies across Europe could help strengthen communication and trust in maternal vaccination.

Enhancement of Vaccination Attitude and Flu Vaccination Coverage among Pregnant Women Attending Birthing Preparation Course

Most vaccinations are recommended within the 15th month of life, in order to reduce risks and to protect children from the initial stages of their lives. A vaccination training session was carried out during the birthing preparation course, aimed at increasing the attitude toward vaccination in maternal-child age. A questionnaire on vaccination awareness was administered before and after the training session and on-site flu vaccination was offered to women and their companions. The percentage of participants who consider the preparatory course a useful tool to obtain information about vaccines increases significantly from 30.34% at pre-intervention to 64.56% at post-intervention (p < 0.001). There is a significant increase in the mean number of vaccinations that the participants want their children to get. The number of participants believing that there is no relationship between vaccination and autism rose from 41.05 to 72.97% (p < 0.001). In total, 48 out of 119 (40.34%) pregnant women participating in the course and 39 companions were vaccinated for influenza. Vaccination knowledge and attitude significantly increased after a training session dedicated to vaccination as a part of the pregnant pre-birth course, whose aim can be therefore extended to the management of the health of the child, well beyond the period of pregnancy, according to the life-course approach to health.

Knowledge, attitudes and practices on influenza vaccination during pregnancy in Quito, Ecuador

Background

Vaccination is the most effective way to prevent infection and severe outcomes caused by influenza viruses in pregnant women and their children. In Ecuador, the coverage of seasonal influenza vaccination in pregnant women is low. The aim of this study was to assess the knowledge, attitudes, and practices (KAP) of pregnant women toward influenza vaccination in Quito-Ecuador.

Methods

A cross-sectional study enrolled 842 women who delivered at three main public gynecological-obstetric units of the Metropolitan District of Quito. A questionnaire regarding demographics, antenatal care, risk conditions and knowledge, attitudes and practices related to influenza vaccination was administered. We examined factors associated with vaccination using log-binomial regression models.

Results

A low vaccination rate (36.6%) against influenza was observed among pregnant women. The factors associated with vaccination included the recommendations from health providers (adjusted PR: 15.84; CI 95% 9.62–26.10), belief in the safety of the influenza vaccine (adjusted PR: 1.53; CI 95% 1.03–2.37) and antenatal care (adjusted PR: 1.21; CI 95% 1.01–1.47). The most common reasons for not vaccinating included the lack of recommendation from health care providers (73.9%) and lack of access to vaccine (9.0%).

Conclusions

Health educational programs aimed at pregnant women and antenatal care providers have the most potential to increase influenza vaccination rates. Further studies are needed to understand the barriers of health care providers regarding influenza vaccination in Ecuador.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-020-10061-4.

Individual and Neighborhood Factors Associated With Failure to Vaccinate Against Influenza During Pregnancy

Uptake of influenza vaccine among pregnant women remains low. We investigated whether unvaccinated pregnant women were clustered geographically and determined factors associated with failure to vaccinate using spatial and multivariate logistic regression analyses. Pregnant women who were members of Kaiser Permanente Northern California in 2015 or 2016 were included in the study. More than half (53%) of the 77,607 included pregnant women were unvaccinated. Spatial analysis identified 5 clusters with a high prevalence of unvaccinated pregnant women. The proportion of unvaccinated women ranged from 57% to 75% within clusters as compared with 51% outside clusters. In covariate-adjusted analyses, residence in a cluster was associated with a 41% increase in the odds of being unvaccinated (odds ratio (OR) = 1.41, 95% confidence interval (CI): 1.36, 1.46). The odds of being unvaccinated were greater for Black women (OR = 1.58, 95% CI: 1.49, 1.69), Hispanic women (OR = 1.15, 95% CI: 1.05, 1.25), women with subsidized health insurance (OR = 1.18, 95% CI: 1.11, 1.24), women with fewer than 5 prenatal-care visits (OR = 1.85, 95% CI: 1.60, 2.16), and neighborhoods with a high deprivation index (fourth quartile vs. first: OR = 1.14, 95% CI: 1.07, 1.21). In conclusion, unvaccinated pregnant women were clustered geographically and by key sociodemographic factors. These findings suggest that interventions to increase influenza vaccine coverage among pregnant women are needed, particularly in vulnerable populations.

Effectiveness of influenza vaccination during pregnancy to prevent severe infection in children under 6 months of age, Spain, 2017-2019

INTRODUCTION

Influenza vaccination is recommended to pregnant women in Spain to reduce the risk of influenza-related complications. Influenza related hospitalizations pose a significant disease burden in children every year. Although children below 6 months are too young to be vaccinated, they can receive protection against influenza through vaccination of their mothers during pregnancy. We estimated the effectiveness of maternal influenza vaccination to prevent influenza hospitalizations in infants under 6 months of age.

METHODS

This is a retrospective pilot study, using data from the Severe Hospitalized Confirmed Influenza Cases (SHCIC) surveillance system in seasons 2017/18 and 2018/19 in Spain. Maternal vaccination status during pregnancy was collected for cases in children 6 months and younger hospitalized with confirmed influenza infection. Influenza vaccine effectiveness was estimated using the screening method, by comparing the proportion of children with vaccinated mothers during pregnancy (proportion of cases vaccinated, PCV), with the vaccination coverage among pregnant women in Spain (proportion of population vaccinated, PPV).

RESULTS

For all the study period, the PCV was 17% and the PPV was 35%. Influenza vaccination in mothers during pregnancy prevented influenza confirmed hospitalizations in infants aged 6 months and younger with a 61% (95%CI: 27-79%) effectiveness.

CONCLUSIONS

In line with evidence from other countries, influenza vaccination during pregnancy protects infants up to 6 months of age from influenza hospitalizations in Spain. These results support current recommendations of influenza vaccination in pregnant women, and more studies are needed in Spain to confirm the double protection of maternal vaccination in mothers and infants.

Factors that influence vaccination decision-making among pregnant women: A systematic review and meta-analysis

BACKGROUND

The most important factor influencing maternal vaccination uptake is healthcare professional (HCP) recommendation. However, where data are available, one-third of pregnant women remain unvaccinated despite receiving a recommendation. Therefore, it is essential to understand the significance of other factors and distinguish between vaccines administered routinely and during outbreaks. This is the first systematic review and meta-analysis (PROSPERO: CRD 42019118299) to examine the strength of the relationships between identified factors and maternal vaccination uptake.

METHODS

We searched MEDLINE, Embase Classic & Embase, PsycINFO, CINAHL Plus, Web of Science, IBSS, LILACS, AfricaWideInfo, IMEMR, and Global Health databases for studies reporting factors that influence maternal vaccination. We used random-effects models to calculate pooled odds ratios (OR) of being vaccinated by vaccine type.

FINDINGS

We screened 17,236 articles and identified 120 studies from 30 countries for inclusion. Of these, 49 studies were eligible for meta-analysis. The odds of receiving a pertussis or influenza vaccination were ten to twelve-times higher among pregnant women who received a recommendation from HCPs. During the 2009 influenza pandemic an HCP recommendation increased the odds of antenatal H1N1 vaccine uptake six times (OR 6.76, 95% CI 3.12-14.64, I2 = 92.00%). Believing there was potential for vaccine-induced harm had a negative influence on seasonal (OR 0.22, 95% CI 0.11-0.44 I2 = 84.00%) and pandemic influenza vaccine uptake (OR 0.16, 95% CI 0.09-0.29, I2 = 89.48%), reducing the odds of being vaccinated five-fold. Combined with our qualitative analysis the relationship between the belief in substantial disease risk and maternal seasonal and pandemic influenza vaccination uptake was limited.

CONCLUSIONS

The effect of an HCP recommendation during an outbreak, whilst still powerful, may be muted by other factors. This requires further research, particularly when vaccines are novel. Public health campaigns which centre on the protectiveness and safety of a maternal vaccine rather than disease threat alone may prove beneficial.

Different perspectives of immunizations during pregnancy

Background/aim

Pregnant women and infants are at risk of severe lower respiratory tract infections induced by influenza or pertussis. The uptake of both vaccines is poor in spite of proven benefits and safety. We aimed to determine the knowledge and attitude of pregnant women and their primary healthcare providers towards immunization during pregnancy.

Materials and methods

This cross-sectional and interventional study was conducted in northern Turkey in 2016. It had 3 different groups including 786 pregnant women, 146 primary healthcare staff, and 97 family practitioners. Different questionnaires were filled by each group. The intervention phase of the study consisted of education of the expectant mothers about immunizations during pregnancy.

Results

786 pregnant women aged between 17–44 years were enrolled to the study. Most of the participants had favourable attitude about vaccination, but only 1.1% had influenza immunization, none had Tdap immunization. None of the participants joining the intervention stage were immunized. The healthcare staff and family physicians had knowledge about vaccinations, but had abstention for administration. Postexposure prophylaxis was also provided by referral centres.

Conclusions

Most of the participants either pregnant women or healthcare workers were not vaccinated against pertussis and influenza. Dissemination of maternal immunization must be supported by the team work of healthcare professionals, authorities, universities, professional associations, stake holders, media and patients with current, evidence based knowledge.

Tetanus, Diphtheria, and Acellular Pertussis and Influenza Vaccinations among Women With a Live Birth, Internet Panel Survey, 2017-2018

Objectives

Pregnant women are at increased risk of complications from influenza, and infants are at increased risk of pertussis. Maternal influenza and Tdap (tetanus, diphtheria, and acellular pertussis) vaccination can reduce risk of these infections and related complications. Our objective was to estimate vaccination coverage with influenza and Tdap vaccines during pregnancy among women with a recent live birth.

Methods

An opt-in Internet panel survey was conducted from March 28 to April 10, 2018 among pregnant and recently pregnant women. Respondents with a live birth from August 1, 2017 through the date in which the participant completed the survey were included in the analysis. Receipt of influenza vaccination since July 1, 2017 and Tdap vaccination during pregnancy were assessed by sociodemographic characteristics, receipt of a health care provider (HCP) recommendation and/or offer of vaccination, and vaccination-related knowledge, attitudes, and beliefs.

Results

Less than a third (30.3%) of women with a live birth were unvaccinated during their pregnancy with both Tdap and influenza vaccines. Almost a third (32.8%) of the women reported being vaccinated with both vaccines. The majority (73.0%) of women reported receiving an HCP recommendation for both vaccines, and 54.2% of women were offered both vaccines by an HCP. Reasons for nonvaccination included negative attitudes toward influenza vaccine and lack of awareness about Tdap vaccination during pregnancy.

Conclusions

Maternal Tdap and influenza vaccinations can prevent morbidity and mortality among infants and their mothers, yet many pregnant women are unvaccinated with either Tdap or influenza vaccines. Clinic-based education, along with interventions, such as standing orders and provider reminders, are strategies to increase maternal vaccination.

Low awareness of influenza vaccination among pregnant women and their obstetricians: a population-based survey in Beijing, China

We assessed how an awareness of influenza vaccination might influence both the willingness of pregnant women to be vaccinated and the readiness of obstetricians to recommend antenatal influenza vaccination in Beijing, China. From March to April 2016, we surveyed pregnant women who were attending antenatal clinics at eight hospitals in Beijing, along with obstetricians at the same clinics. Demographic, attitudinal, and behavioral information regarding influenza vaccination were collected using structured questionnaires. Consent and completed questionnaires were obtained from 988 of 1009 pregnant women and 165 of 173 obstetricians. Only 113 (11.4%) pregnant women reported being willing to receive an influenza vaccine during their pregnancies. Willingness to receive an influenza vaccination was positively associated with ever having a history of vaccination or influenza (aOR=6.74, 95%CI: 1.72-26.4, P=0.006), perceiving benefits of vaccination (aOR=1.67, 95%CI: 1.00-2.79, P=0.050), and having a higher level of influenza knowledge (aOR=82.2, 95%CI: 21.7-311.1, P<0.001). Among obstetricians, only 19.4% reported being willing to recommend influenza vaccination to their pregnant patients and 15.2% reported knowledge that influenza vaccination during pregnancy was recommended by China's National Health Commission. Neither pregnant women nor their obstetricians were aware of Chinese government recommendations that antenatal influenza vaccination should be encouraged and provided. Pregnant women and their obstetricians were ill-informed of the relevant evidence. It is in emergent need to train and disseminate the updated evidence on influenza vaccination to obstetricians. It also warranted more high-quality trials regarding influenza vaccination during pregnancy to address public concern.

Knowledge about influenza and adherence to the recommendations for influenza vaccination of pregnant women after an educational intervention in Greece

Pregnant women and young infants are at increased risk for influenza-associated severe disease, complications and hospitalizations. In Greece influenza vaccination during pregnancy remains extremely low. We studied the knowledge about influenza and the adherence to the recommendations for influenza vaccination of pregnant women following an educational intervention in a large maternity hospital. A standardized questionnaire was used. A knowledge score was calculated for each woman. A total of 304 pregnant women were studied [mean age: 31.5 years (standard deviation (SD): 5.4 years), mean gestational age: 27.8 weeks (SD: 9.6 weeks)]. Their mean knowledge score was 87%. Sixty pregnant women (19.5%) were vaccinated against influenza at a mean gestational age of 24.6 weeks (SD: 7.5 weeks). Multiple regression analysis revealed that previous influenza vaccination and information about the need to get vaccinated were the only significant factors associated with an increased probability for influenza vaccination during pregnancy (47% versus 17% in women with and without a history of influenza vaccination in the past, respectively; odds ratio = 3.6; p-value = 0.016, and 32% versus 4% in women informed compared to those uninformed about the need for vaccination during pregnancy, respectively; odds ratio = 17.8; p-value<0.001). Seventy women provided a reason for refusing influenza vaccination. "Fear of adverse events" (for them or the fetus) was the prevalent reason for refusing influenza vaccination (19 women; 27%), followed by the statements "influenza vaccination is not necessary" (13; 18.5%) and "not at risk to get influenza" (9; 13%). In conclusion, an educational intervention was associated with an influenza vaccination rate of 19.5% among pregnant women compared to <2% the past years. In order to improve vaccine uptake by pregnant women and protect them and their babies, more intensified interventions should be explored.

Adherence and Concordance of Influenza and Pertussis Vaccination Coverage in Pregnant Women in Spain

Background: Pregnant women should receive two vaccines during pregnancy due to maternal-foetal complications and risks as well as the influenza and pertussis vaccinations. The goal was to evaluate vaccination coverage against influenza and pertussis in pregnant women, following midwife professional advice during the pregnancy follow-up; Methods: Prospective cohort study of 1017 pregnancies during the vaccination campaign in 2015⁻2016. To estimate the degree of consistency between the coverage declared by mothers and that registered in the Nominal Vaccination Registry (NVR), we used the Cohen's kappa index (k); Results: 95.4% were registered in the NVR. Vaccination coverage recorded against influenza was 64.2% (95% CI: 61.2⁻67.2), and 89.8% (95% CI: 87.9⁻91.7) against pertussis. The coverage of the pregnant women interviewed was 61.7% (95% CI: 58.1⁻67.3)) for influenza and 92.3% (95% CI: 91.4⁻95.3) for pertussis. Subsequent interviews of 67.2% of the women produced a kappa agreement index between the data obtained from interviews and those recorded in the NVR of 0.974 (IC95%: 98.0⁻99.6) for influenza, and 0.921 (IC95%: 98.1⁻99.7) for pertussis. The women identified midwives as the main source of vaccination information and advice 88.4% (IC95%: 85.8⁻90.9); Conclusions: The NVR is an effective platform for estimating immunisation coverage in pregnant women. The degree of agreement between declared vaccinations and registered vaccinations was high for both vaccines.

Factors influencing refusing of flu vaccination among pregnant women in Italy: Healthcare workers' role

BACKGROUND

Pregnant women are at increased risk of influenza complications. Influenza vaccine provides them a substantial protection.

OBJECTIVE

The aim of this study was to investigate determinants associated with non-adherence to influenza vaccine recommendations in pregnant women in Italy.

METHODS

A cross-sectional study has been carried out among pregnant women attending their follow-up visit in some mother and child services in a Region of Italy from October 2016 to January 2017. The study protocol was approved by the local research Ethics. A self-administered close-ended questionnaire has been administered to the pregnant women. Differences in background, socio-demographic characteristics, knowledge and attitudes towards flu vaccine were tested in vaccinated and unvaccinated women. Multivariate analysis was performed to control for confounding factors.

RESULTS

Three hundred and sixty-six women answered the survey (97% response rate) and 96.1% (348) declared of being unvaccinated against influenza during the 2016-2017 influenza season. Frequent reasons for refusing vaccination were drugs objection and concerns about vaccines' effects. According to the refusal attitude, influenza knowledge was low in the group. Moreover, analysis showed that low adherence to vaccination is associated to lacking promotion of vaccination to pregnant women carried out by healthcare workers (P < 0.005).

CONCLUSIONS

Healthcare workers have a key role in assisting women during the gestational period, so their active involvement in vaccination promotion is essential. It is necessary to improve health care workers' knowledge about vaccine relevance in protecting pregnancy and their communication skills to properly inform pregnant women.

Exploring the risk of severe outcomes and the role of seasonal influenza vaccination in pregnant women hospitalized with confirmed influenza, Spain, 2010/11-2015/16

Based on previous observations during pandemics and seasonal epidemics, pregnant women are considered at risk of developing severe influenza outcomes after influenza infection. With the aim of preventing severe influenza illness, the World Health Organization (WHO) includes pregnant women as a target group for seasonal influenza vaccination. However, influenza vaccine uptake during pregnancy remains low in many countries, including Spain. The objectives of this study were to increase the evidence of pregnancy as a risk factor for severe influenza illness and to study the potential role of seasonal influenza vaccination in the prevention of severe outcomes in infected pregnant women. Using information from the surveillance of Severe Hospitalized Confirmed Influenza Cases (SHCIC) in Spain, from seasons 2010/11 to 2015/16, we estimated that pregnant women in our study had a relative risk of hospitalization with severe influenza nearly 7.8 times higher than non-pregnant women of reproductive age. Only 5 out of 167 pregnant women with known vaccination status in our study had been vaccinated (3.6%). Such extremely low vaccination coverage only allowed obtaining crude estimates suggesting a protective effect of the vaccine against influenza complications (ICU admission or death). Our overall results support that pregnant women could benefit from seasonal influenza vaccination, in line with national and international recommendations.

Vaccination of pregnant women in the Valencian Community during the 2014-15 influenza season: a multicentre study

OBJECTIVE

To study influenza vaccination uptake in pregnant women from three Health Departments in the Valencian Community (Spain) during the 2014-15 flu season, to identify degree of knowledge, sources of information and attitudes toward immunization against influenza.

METHODS

Multicentre cross-sectional descriptive study during the 2014-15 vaccination campaign. Vaccine coverage was determined using the Nominal Vaccination Registry (NVR). Subsequently, a telephone survey was carried out on a sample of vaccinated and unvaccinated postpartum women.

RESULTS

The NVR had information on 934 (59.5%) out of 1,569 postpartum women; distribution per Health Departments was: 420 (44.9%), 161 (17.2%) and 353 (37.8%) in La Ribera, Torrevieja and Elx-Crevillent respectively. Vaccine uptake was 27.9% (n = 261). According to the "Country of Origin" variable, 77.5% (n = 724) of women were Spanish, with a vaccination rate of 26.7% (n = 193), compared to 22.5% (n = 210) who were non-Spanish, with a rate of 32.4% (n = 68). The main source of information was midwives for 83.7% (n = 159) of vaccinated pregnant women and for 44.6% (n = 127) of non-vaccinated women. The main reasons for vaccine refusal were lack of awareness (29.5%, n = 84) and not considering it necessary (25.6%, n = 73).

CONCLUSIONS

Despite their high willingness to be vaccinated after receiving information about the flu vaccine, the vaccination coverage in pregnant women studied is still low and can be improved. Health professionals need new information strategies to extend vaccine uptake to a larger number of pregnant women in Spain. Midwife advice plays an essential role in transmitting information on influenza vaccination in pregnant women and has a significant impact on uptake.

Use of social networking sites and women's decision to receive vaccinations during pregnancy: A cross-sectional study in the UK

In the UK, it is recommended that pregnant women receive the influenza and pertussis vaccination. However, uptake of these vaccinations in certain UK regions remains low. Previous studies show that pregnant women use the internet to access health information, yet it has not been previously explored whether the use of social networking sites (SNS) influences decisions about maternal vaccination uptake. The aim of this study was to determine, if the use of SNS to gain information on pregnancy vaccinations, is associated with women's uptake of the influenza and pertussis vaccines during pregnancy. This is a cross-sectional study with data collected using an online questionnaire posted on Mumsnet (an online parenting site), from 3rd to 24th August 2017. Women were included if they lived in the UK, were over 32 weeks pregnant, or had given birth in the last year. Participants were questioned about their pregnancy vaccination uptake, general SNS use and, their SNS use in relation to gathering information on vaccinations during pregnancy. The data was analysed using chi-square test, and univariable and multivariable logistic regression. Out of a sample of 308 participants, 305 (99.3%) of women reported using SNS and 64/308 (20.8%) of women reported using SNS to gather information on vaccinations during pregnancy. Women who reported using SNS to gather information on pregnancy vaccinations were 58% (adjusted odds ratio 0.42; 95% CI 0.21-0.87) less likely to receive the pertussis vaccination during pregnancy. However, the association was not statistically significant for the influenza vaccination (adjusted odds ratio 0.64; 95% CI 0.37-1.11). The study showed many women use SNS to gather information on pregnancy vaccinations, and this is negatively associated with their likelihood of receiving the pertussis vaccine. Future studies are needed to analyse the accuracy and quality of the vaccination information, which women find on SNS.

Influence of health literacy on acceptance of influenza and pertussis vaccinations: a cross-sectional study among Spanish pregnant women

OBJECTIVES

Immunisations against influenza and Bordetella pertussis infection are recommended to pregnant women in Valencia (Spain), yet vaccination rates remain low. Health literacy (HL) appears as a crucial factor in vaccination decision-making. We explored the relation between HL of pregnant women and decisions to receive influenza and pertussis immunisations.

SETTING

University hospital in Valencia (Spain).

PARTICIPANTS

119 women who gave birth at a hospital in Valencia (Spain) between November 2015 and May 2016. Women in the immediate postpartum period (more than 27 weeks of gestation), between November 2015 and May 2016 were included in the study. Women with impairments, language barriers or illiteracy which prevented completion of the questionnaires, or those who were under 18 years were excluded from enrolment.

PRIMARY AND SECONDARY OUTCOME MEASURES

HL level; influenza and pertussis immunisation rate; reasons for rejection of vaccination.

RESULTS

119 participants were included (mean age 32.3±5.5 years, 52% primiparous, 95% full-term deliveries). A higher education level was associated with Short Assessment of Health Literacy for Spanish Adults _50 (adjusted R²=0.22, p=0.014) and Newest Vital Sign (adjusted R²=0.258, p=0.001) scores. Depending on the scale, 56%-85% of participants had adequate HL. 52% (62/119) and 94% (112/119) of women received influenza and pertussis immunisation, respectively. Women rejecting influenza vaccine had a higher HL level (measured by SALHSA_50 tool) than those accepting it (Kruskal-Wallis test p=0.022). 24% of women who declined influenza vaccination felt the vaccine was unnecessary, and 23% claimed to have insufficient information.

CONCLUSIONS

Influenza vaccination rate was suboptimal in our study. Women with high HL were more likely to decline immunisation. Information from professionals needs to match patients' HL levels to reduce negative perceptions of vaccination.

Patient's behaviors and missed opportunities for vaccination against seasonal epidemic influenza and evaluation of their impact on patient's influenza vaccine uptake

Objectives

Influenza vaccination (IV) coverage remains low in France. Objectives were to assess patient knowledge and behaviors and missed opportunities for vaccination (MO) and their impact on vaccine uptake.

Methods

This is a prospective-observational study, including emergency department patients at risk for severe influenza. Patients were interviewed about their knowledge and behaviors. We evaluated the health-care voucher scheme (HCVS) and MO.

Results

868 patients were included. Vaccine uptake was 33.2%, 42% of patients knew about the possible severity of influenza, 23% thought that they were not at risk for severe influenza, 39% knew that they have an indication for the vaccine, and 4.3% to 11.5% expressed reservations concerning IV side effects and effectiveness. HCVS was used by 44.3% of patients, but only 14.8% had been vaccinated. MO were reported by 484 patients (69.4%) declaring 1104 consultations and 148 IV propositions (86.6%). Predictors of vaccine uptake (p<0.0001) were: knowledge of serious and fatal influenza forms [OR 0.36 (CI95% 0.25–0.5)]; confidence in influenza vaccine effectiveness [0.38 (0.2–0.7)]; opposition to vaccines [0.22 (0.1–0.48)]; visit to general practitioner [4.53 (2.9–7.1)]; general practitioner proposed IV [2.1 (1.2–3.4)].

Conclusion

Our results indicate that high rate of missed opportunities, some patient behaviors and general practitioner visits may explain low influenza vaccine uptake, and that HCVS use is a complex process. Of interest, we found that the patient’s knowledge of the potential severity of influenza is not sufficient to promote vaccine, suggesting that the information strategy must be adapted to each patient behavior.

The crucial role of maternal care providers as vaccinators for pregnant women

Vaccination during pregnancy is increasingly being recognised internationally a useful means of preventing illness in pregnant women and their newborns. It has been used since the 1960s, when it was found that tetanus vaccine was highly effective in preventing neonatal tetanus, but interest has greatly increased over the last few years. As new data become available showing the numerous benefits of maternal immunisation and its potential for improving maternal and neonatal health in relation to a number of infectious conditions, it is being increasingly incorporated into the national vaccination programmes around the world. However, the development of new vaccines, the existence of clinical trials testing the efficacy of vaccinating pregnant women in order to protect newborns against respiratory syncytial virus and group B Streptococcus infections, and the fact that the uptake of influenza and pertussis vaccines during pregnancy is lower than expected in developed countries is making it increasingly clear that existing maternal vaccination programmes need to be strengthened. This reviews addresses the importance of integrating maternal immunisation and standard obstetrical care in order to promote vaccination administration by maternal care providers (MCPs) because the vaccination goals for pregnant women cannot be achieved without appropriate training and extending the role of MCPs as vaccinators. In order to make meaningful progress, it is necessary to develop and refine targeted messages for pregnant women concerning the benefits of maternal immunisation for themselves and their infants.