Influenza vaccination in pregnancy: vaccine uptake, maternal and healthcare providers' knowledge and attitudes. A quantitative study

Knowledge, attitudes, and beliefs of pharmacists regarding vaccinations against influenza and pneumococci - a systematic review

Pharmacists' knowledge, attitudes, and beliefs regarding vaccination can significantly influence patients' willingness to receive vaccinations. This study aims to assess the level of knowledge, attitudes, and beliefs of pharmacists toward influenza and pneumococcal vaccinations. On February 17, 2024, a systematic search was conducted in the Medline (via PubMed), Embase (via Ovid), and The Cochrane Library databases, following PRISMA guidelines. Before analyzing the results, the study protocol was registered in the PROSPERO database (CRD42024566984). Of the 1,209 studies identified, 24 publications met the inclusion criteria for analysis. Most of these (n = 22) were cross-sectional studies using proprietary questionnaires. The studies found that pharmacists possess unsatisfactory knowledge about influenza and pneumococcal vaccinations. Shortcomings in attitudes and beliefs about vaccination safety were also evident, along with a deficiencies of promotion of vaccinations to patients.

Influenza vaccine during pregnancy, recommendations from healthcare providers, and race/ethnicity in the United States

OBJECTIVES

We examined racial/ethnic differences in the association between influenza vaccine recommendations from healthcare providers and maternal vaccination uptake.

METHODS

This cross-sectional study examined data from the Pregnancy Risk Assessment Monitoring System. We categorized respondents as non-Hispanic (NH) Whites, NH-Blacks, NH-Asians, American Indians/Alaska Natives, NH Other non-Whites, and Hispanics. We conducted multivariable logistical regression models to evaluate adjusted odds ratios (AOR) and 95% confidence intervals (CI). Covariates included maternal age, marital status, education, insurance status before pregnancy, the number of previous live births, the number of prenatal care visits, and smoking status during pregnancy.

RESULTS

The prevalences of receiving influenza vaccine recommendations from healthcare providers and maternal vaccine were 80.01% and 50.42%, respectively. NH-Blacks are less likely to receive provider recommendations (AOR = 0.82; 95%CI 0.77-0.87) and be vaccinated (AOR = 0.76; 95%CI 0.72-0.80) than NH-Whites. Receiving provider recommendations was significantly associated with increased maternal influenza vaccine uptake (AOR = 15.50; 95% CI 14.51-16.55). The associations were significant for all racial/ethnic groups, with the highest among NH-Asians (AOR = 22.04; 95% CI 17.88-27.16) and the lowest among NH Other non-Whites (AOR = 11.07; 95% CI 8.25-14.86). Within NH-Asians, effectiveness among Chinese was highest (AOR = 29.39; 95% CI 18.10-47.71).

CONCLUSIONS

Racial/ethnic disparities in maternal influenza vaccine uptake and receiving vaccine recommendations from healthcare providers persisted. Further studies on the racial/ethnic disparities in maternal vaccination were warranted and tailored strategies are required to reduce this health disparity.

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.

A scoping review of the reasons for and approaches to non-uptake of pertussis and influenza vaccinations in pregnant women in the United Kingdom and Ireland

BACKGROUND

Pertussis and influenza cause significant morbidity and mortality in pregnancy and the neonatal period. Maternal vaccination in pregnancy would reduce harm, but low vaccine uptake is a concern. This scoping review aimed to understand the reasons for, and approaches, to non-uptake of pertussis and influenza vaccinations in pregnant women in the UK and Ireland.

METHODS

The inclusion criteria of this scoping review consist of pregnant women who avail of pertussis and influenza vaccines in the UK and Ireland. MEDLINE, EMBASE, Web of Science and CINAHL databases were searched in June 2021 and updated in October 2022. Searches were limited to English language reports published after 2011. We followed the Joanna Briggs Institute guidance on scoping reviews. Data were extracted and charted.

RESULTS

Five themes emerged from the literature. Acceptability, as well as organisational and awareness issues, were overarching themes regarding reasons for and approaches to non-uptake of the vaccines respectively. Other themes included healthcare professional factors, information interpretation and pregnancy-related factors.

CONCLUSIONS

Women need clear, comprehensible information, ideally provided by their healthcare professionals, in a way that is meaningful and addresses their circumstances and risk perceptions. This research will serve as a base for future work that aims behaviour science interventions at the wider pregnant population as well as the target groups that have been identified in this review.

Individual and neighborhood factors associated with being unvaccinated against COVID-19 among pregnant persons

We investigated whether unvaccinated pregnant persons cluster geographically and determined factors associated with being unvaccinated using spatial and multivariate logistic regression analyses. Pregnant persons with deliveries from December 15, 2020, through September 30, 2022, at Kaiser Permanente Northern California were included. Of the 85,852 pregnant persons in the study, 46.6% were unvaccinated before and during pregnancy. Spatial analysis identified 5 clusters with high prevalence of unvaccinated pregnant persons. Within these clusters, the proportion of unvaccinated varied from 53% to 62% versus 39% outside the clusters. In covariate-adjusted analyses, residence in a cluster increased the odds of being unvaccinated by 1.64 (95% confidence interval (CI): 1.59,1.69). The odds of being unvaccinated increased among those aged 16-24 years (odds ratio [OR] = 2.69, CI: 2.55, 2.83), aged 25-34 years (OR = 1.59, CI: 1.54, 1.64) compared with age ≥ 35 years, black race (OR = 1.45, CI:1.37, 1.54), and subsidized insurance (OR = 1.32, CI: 1.26, 1.38). The odds of being unvaccinated also increased for pregnant persons living in neighborhoods where the proportion of adults with high school education or less was greater than 20%. Geographic clustering of unvaccinated pregnant persons suggests a need for population-specific-interventions to increase vaccine coverage.

Vaccination against influenza in pregnant women in a maternity hospital in the Czech Republic in the season 2020-2021

OBJECTIVES

Pregnant women are among the priority groups to receive influenza vaccines in the Czech Republic since 2011, data on vaccination coverage are not yet available. The aim of the study was to determine the influenza vaccination coverage (IVC) and provide source data for further activities.

METHODS

A prospective observational study was performed in a large maternity hospital in Prague. The self-completed questionnaire was distributed to 5,475 pregnant women between September 1, 2020 and August 31, 2021. Questions included maternal sociodemographic characteristics, influenza vaccination status and sources of maternal vaccination recommendations during pregnancy.

RESULTS

A total of 4,617 completed questionnaires have been analysed. The median age of study participants (N = 4,592) was 33 years (range: 18-51 years). The majority (69.7%) of women had completed their university education, most women were childless (58.5%) or had one child (32.5%) before the start of the study. Less than 2% of women reported being vaccinated against influenza during their pregnancy (1.5%; 95% CI, 1.1-1.9%). Only 21% of women knew that it's possible to get vaccinated against influenza during pregnancy. Participants considered influenza vaccination in pregnancy as important (3.3%), useful (41.1%) and useless (44.4%). Out of 959 pregnant women who had information about influenza vaccination during pregnancy, only 6.9% were vaccinated, while among those who did not have this information, 0.1% were vaccinated during pregnancy (p < 0.001). The most frequent source of information was Internet, then media and a general practitioner.

CONCLUSIONS

The IVC during pregnancy in our study was extremely low. In order to improve IVC among pregnant women, it is necessary to increase awareness of recommendations and vaccination options among the public and professionals and incorporating vaccination recommendation in routine antenatal practice.

Acceptance of vaccination against pertussis, COVID-19 and influenza during pregnancy: a cross-sectional study

Background

This study aims to assess the uptake of maternal pertussis and COVID-19 vaccination and the intention towards accepting the maternal influenza vaccination. Insights into different socio-demographic factors related to maternal vaccination coverage might help to address vaccine acceptance and improve maternal vaccine uptake in the future.

Methods

We conducted a cross-sectional survey among pregnant women and recent mothers, up to 6 months post-partum. The primary outcome measures of this study were behaviour for maternal pertussis and COVID-19 vaccination, and maternal influenza vaccination intention. Associations between socio-demographic factors and maternal pertussis vaccination and maternal COVID-19 vaccination behaviour; and socio-demographic factors and maternal influenza vaccination intention were assessed using binary logistic regression analyses.

Results

In total 1361 respondents filled out the questionnaire. Almost all women (95%) were vaccinated against pertussis during pregnancy, while almost two-third were vaccinated against COVID-19 during pregnancy (58%) and almost one-third (28%) had a positive intention towards receiving the maternal influenza vaccination. Results show that young maternal age and low education level were associated with lower maternal vaccination acceptance.

Conclusion

Vaccination campaigns focusing on the severity of diseases that are prevented, are needed to increase maternal vaccine acceptance in younger and low-educated pregnant women. We expect that differences in vaccination coverage between the three maternal vaccinations might partly be explained by existing recommendations, campaigns and whether the vaccination is part of the national immunisation program.

Impact of the COVID-19 Pandemic on Influenza Vaccination and Associated Factors among Pregnant Women: A Cross-Sectional Study in Korea

Pregnant women are vulnerable to developing influenza complications. Influenza vaccination during pregnancy is crucial to avoid infection. The COVID-19 pandemic might exacerbate fear and anxiety in pregnant women. The purpose of this study was to evaluate the effect of the COVID-19 pandemic on influenza vaccination and determine the factors associated with influenza vaccine acceptance among pregnant women in Korea. We conducted a cross-sectional study using an online survey in Korea. A survey questionnaire was distributed among pregnant or postpartum women within 1 year after delivery. Multivariate logistic regression analysis was performed to identify the factors associated with influenza vaccination among pregnant women. A total of 351 women were included in this study. Of them, 51.0% and 20.2% were vaccinated against influenza and COVID-19 during pregnancy, respectively. The majority of participants who had a history of influenza vaccination reported that the COVID-19 pandemic did not affect (52.3%, n = 171) or increased the importance (38.5%, n = 126) of their acceptance of the influenza vaccine. Factors associated with influenza vaccine acceptance were knowledge of influenza vaccine (OR 1.21; 95% CI 1.09, 1.35), trust in healthcare providers (OR 2.57; 95% CI 1.43, 4.65), and COVID-19 vaccination during pregnancy (OR 6.11, 95% CI 2.86, 13.01). Participants were more likely to accept the influenza vaccine when they received a COVID-19 vaccine during pregnancy, but the rate of influenza vaccination was not affected by the COVID-19 pandemic. This study showed that the COVID-19 pandemic did not influence influenza vaccine uptake in the majority of pregnant women in Korea. The results emphasize the necessity of appropriate education for pregnant women to enhance awareness of vaccination.

Factors influencing healthcare professionals' confidence in vaccination in Europe: a literature review

Health-care professionals (HCPs) have a fundamental role in vaccination, their own beliefs and attitudes affecting both their uptake and recommendation of vaccines. This literature review (n = 89) summarises evidence on HCPs’ perceptions of the risks and benefits of vaccination, trust, and perceptions of mandatory vaccination in Europe. HCPs across studies believed that vaccination is important to protect themselves and their patients. However, beliefs that some diseases such as influenza are less risky were reported by some HCPs as a reason for not getting vaccinated. Concerns about both short- and long-term side effects were identified among HCPs in most studies, such as those affecting the immune or neurological system. Mistrust toward health authorities and pharmaceutical industry was reported in some studies. The question of mandatory vaccination revealed mixed opinions, with some favoring self-determination and others viewing vaccination as a duty. This review highlights key factors influencing HCPs’ confidence in vaccination in Europe.

Knowledge, attitudes, and practices regarding vaccination among community pharmacists

Background:

Healthcare professionals’ vaccine recommendation is the most effective method to increase vaccination rates of the community. The vaccine counseling and recommendation behavior of pharmacists, who are among the easily accessible healthcare professionals, are influenced by their knowledge and attitudes about vaccines.

Aim:

It was aimed to investigate community pharmacists’ knowledge, attitudes, and practices regarding commonly used vaccines.

Methods:

A cross-sectional study was conducted as an online survey with a sample of 1100 community pharmacists in Turkey. Pharmacists were invited to participate in the study by phone calls. A structured survey, which consists of 40 questions to assess the knowledge, attitudes, and practices regarding vaccines, was sent to the e-mail addresses of pharmacists who volunteered to participate in the study.

Findings:

A total of 430 pharmacists completed the survey. Thirty percent of pharmacists had lack of knowledge about vaccination during pregnancy, whereas 52.2% and 31.4% of pharmacists believed that tetanus and influenza vaccines should be provided during pregnancy, respectively. Nearly 89% of pharmacists recommended vaccines to patients, mainly for influenza vaccine (83.9%). Only 31.5% of pharmacists had been vaccinated against influenza in the last season, whereas 50.5% had never been vaccinated. Pharmacists who had been vaccinated with influenza vaccine had a high rate of recommending influenza vaccines to the patients.

Conclusion:

The present study found that vaccination among pharmacists in Turkey and their knowledge on vaccination during pregnancy were low. Further education of pharmacists to improve their knowledge and attitudes toward vaccines is needed.

Targeting the Toll-like receptor pathway as a therapeutic strategy for neonatal infection

Toll-like receptors (TLRs) are crucial transmembrane receptors that form part of the innate immune response. They play a role in the recognition of various microorganisms and their elimination from the host. TLRs have been proposed as vital immunomodulators in the regulation of multiple neonatal stressors that extend beyond infection such as oxidative stress and pain. The immune system is immature at birth and takes some time to become fully established. As such, babies are especially vulnerable to sepsis at this early stage of life. Findings suggest a gestational age-dependent increase in TLR expression. TLRs engage with accessory and adaptor proteins to facilitate recognition of pathogens and their activation of the receptor. TLRs are generally upregulated during infection and promote the transcription and release of proinflammatory cytokines. Several studies report that TLRs are epigenetically modulated by chromatin changes and promoter methylation upon bacterial infection that have long-term influences on immune responses. TLR activation is reported to modulate cardiorespiratory responses during infection and may play a key role in driving homeostatic instability observed during sepsis. Although complex, TLR signaling and downstream pathways are potential therapeutic targets in the treatment of neonatal diseases. By reviewing the expression and function of key Toll-like receptors, we aim to provide an important framework to understand the functional role of these receptors in response to stress and infection in premature infants.

'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.

National predictors of influenza vaccine uptake in pregnancy: the FluMum prospective cohort study, Australia, 2012-2015

OBJECTIVE

Ascertain predictors of inactivated influenza vaccine (IIV) uptake in pregnancy in mother-infant pairs from six Australian sites over four consecutive influenza seasons (2012-2015).

METHODS

Prospective observational cohort study calculating proportions of unvaccinated and vaccinated pregnancies. Multivariable logistic regression calculating adjusted odds ratios (aOR) and 95% confidence intervals (95%CI) to determine demographic, pregnancy and birth characteristics as predictors of IIV uptake in pregnancy.

RESULTS

Uptake of IIV was 36% (n=3,651/9,878) with only 3-4% during the first trimester. Validation of IIV receipt was obtained for 77% of vaccinated participants. Predictors of IIV uptake in pregnancy were: healthcare provider recommendation to have IIV during pregnancy (aOR 7.04 [95%CI 5.83-8.50]): GP (aOR 4.12 [95%CI 3.43-4.98]), obstetrician (aOR 4.41 [95%CI 3.45-5.64]), midwife (aOR 1.88 [95%CI 1.51-2.36]); previous IIV within 12 months of their current pregnancy (aOR 2.87 [95%CI 2.36-3.50]); and pertussis vaccination during the current pregnancy (aOR 4.88 [95%CI 4.08-5.83]). Conclusions and implications for public health: Healthcare provider discussions with pregnant women about the risks associated with influenza infection during pregnancy and early infancy and evidence about the safety and effectiveness of IIV are required. Recommending and offering IIV in pregnancy needs to be included in these discussions to improve uptake.

Protective vaccinations during pregnancy - adult Poles knowledge in this area

BACKGROUND

The vaccine is a preparation of biological origin containing antigens that stimulate the body's immune system to produce acquired immunity. Vaccines can contain killed or "live" (attenuated) microorganisms as well as fragments of these (antigens). Although many vaccines are used routinely in pregnancy to provide a seroprotective immune response for mother, fetus and neonate there is much controversy over their use during this unique time. The aim of the study was to find out about the knowledge of adult Poles on the use of preventive vaccinations during pregnancy.

METHODS

The study involved 700 people (100%) aged 18 to 80 years ([Formula: see text] = 32.16 ± 16.46). Most of the respondents were women (511; 73%). The study consisted of 9 questions about preventive vaccinations of pregnant women and 5 questions about members of the studied group. The aforementioned questions formed the basis of the preparation of the presented article.

RESULTS

A significant part of respondents (322; 46%) did not have knowledge on the topic of safeness of using preventive vaccinations during pregnancy, 196 (28%) respondents believed that such procedure is not safe. Most of the respondents (371; 53%) did not know about the possibility of using "live" vaccines during pregnancy. 14 (2%) of respondents believed that pregnancy should be terminated in case of administration of a "live" vaccine to a pregnant woman. According to 294 (42%) respondents, vaccinations with "live" vaccines should be completed at least 3 months before the planned pregnancy. The subjects were not aware of the issue of post-exposure vaccination against tetanus and rabies among pregnant women. The respondents' responses were divided on the issue of the safest trimester of pregnancy for vaccine administration. Almost 1/3 of the respondents (203; 29%) indicated the third trimester as the safest for their performance.

CONCLUSION

The knowledge of the surveyed group, the majority of whom were women, about the use of vaccinations before and during pregnancy was unsatisfactory. There is a need to educate the public about the benefits and risks of performing or avoiding preventive vaccinations during pregnancy.

Antenatal care providers' attitudes and beliefs towards maternal vaccination in Kenya

Background: Maternal immunization is known to be one of the best strategies to protect both mothers and their infants from infectious diseases. Studies have shown that healthcare providers play a critical role in implementation of maternal immunization. However, little is known about providers' attitudes and beliefs towards vaccination that can influence their vaccine recommendations, specifically in low to middle income countries (LMIC). Methods: A self-administrated knowledge, attitude and behavior (KAB) survey was provided to 150 antenatal care providers across four different regions (Nairobi, Mombasa, Marsabit, and Siaya counties) of Kenya. The research staff visited the 150 clinics and hospitals and distributed a quantitative KAB survey. Results: Nearly all of the antenatal care providers (99%) recommended tetanus maternal vaccination. Similarly, 99% of the providers agreed that they would agree to provide additional vaccinations for pregnant women and reported that they always advise their patients to get vaccinated. Between 80 and 90% of the providers reported that religious beliefs, ethnicity, cultural background and political leaders do not affect their attitude or beliefs towards recommending vaccines. Conclusions: Considering the positive responses of healthcare providers towards vaccine acceptance and recommendation, these results highlight an opportunity to work in partnership with these providers to improve coverage of maternal vaccination and to introduce additional vaccines (such as influenza). In order to achieve this, logistical barriers that have affected the coverage of the currently recommended vaccines, should be addressed as part of this partnership.

Uptake of vaccination in pregnancy

Maternal immunisation is a public health strategy that aims to provide protection against certain infections to both mother and her foetus or newborn child. Vaccination of pregnant women induces vaccine-specific antibodies that lead to the subsequent transfer of these antibodies across the placenta or through breastfeeding to the offspring. At present, vaccinations in pregnancy are limited to pertussis, tetanus, diphtheria, polio, and the seasonal Influenza vaccine. Recently, some countries have incorporated routine antenatal vaccinations in their national immunisation programmes. Future vaccines targeted at pregnant women such as respiratory syncytial virus (RSV) and Group B streptococcus (GBS) are under development. The recently approved Covid-19 vaccines have no safety data for use in pregnancy at present, but have been considered in the UK in extremely vulnerable pregnant women or pregnant frontline health and social care workers.

In this article, we review the evidence supporting maternal immunisation and discuss the uptake of vaccines in pregnant women, challenges of recording the data on vaccine coverage, and consider reasons behind the present levels of uptake and strategies for future improvements.

Sociodemographic and health-related determinants of seasonal influenza vaccination in pregnancy: A systematic review and meta-analysis of the evidence since 2000

INTRODUCTION

Vaccination is considered to be the most practical and effective preventative measure against influenza. It is highly recommended for population subgroups most at risk of developing complications, including pregnant women. However, seasonal influenza vaccine uptake remains suboptimal among pregnant women, even in jurisdictions with universal vaccination. We summarized the evidence on the determinants of seasonal influenza vaccine uptake during pregnancy to better understand factors that influence vaccine uptake among pregnant women.

MATERIAL AND METHODS

We systematically searched MEDLINE, Embase and CINAHL from January 2000 to February 2020 for publications in English reporting on sociodemographic and/or health-related determinants of seasonal influenza vaccine uptake during pregnancy. Two reviewers independently included studies. One reviewer extracted data and assessed study quality, and another reviewer checked extracted data and study quality assessments for errors. Disagreements were resolved through consensus, or a third reviewer. We meta-analyzed using the inverse variance, random-effects method, and reported the odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

From 1663 retrieved citations, we included 36 studies. The following factors were associated with increased seasonal influenza vaccine uptake: Older age (20 studies: OR 1.13, 95% CI 1.07-1.20), being nulliparous (13 studies: OR 1.26, 95% CI 1.15-1.38), married (8 studies: OR 1.11, 95% CI 1.07-1.15), employed (4 studies: OR 1.13, 95% CI 1.02-1.24), a non-smoker (8 studies: OR 1.25, 95% CI 1.04-1.51) and having prenatal care (3 studies: OR 3.36, 95% CI 2.25-5.02), a chronic condition (6 studies: OR 1.30, 95% CI 1.17-1.44), been previously vaccinated (9 studies: OR 4.88, 95% CI 3.14-7.57) and living in a rural area (9 studies: OR 1.09, 95% CI 1.05-1.14). Compared with being black, being white was also associated with increased seasonal influenza vaccine uptake (11 studies: OR 1.30, 95% CI 1.20-1.41).

CONCLUSIONS

The evidence suggests that several sociodemographic and health-related factors may determine seasonal influenza vaccination in pregnancy, and that parity, history of influenza vaccination, prenatal care and comorbidity status may be influential.

Incidence, risk factors and impact of seasonal influenza in pregnancy: A national cohort study

BACKGROUND

Pregnant women are particularly vulnerable to severe infection from influenza resulting in poor neonatal outcomes. The majority of evidence relates to pandemic 2009 A/H1N1 influenza. The objective of this study was to describe the characteristics and outcomes of pregnant women hospitalised with seasonal influenza.

METHODS

This national, prospective, observational cohort study used the UK Obstetric Surveillance System (UKOSS) to identify all pregnant women admitted to hospital between 01/11/2016 and 31/10/2018 with laboratory confirmed influenza at any gestation and up to two days after giving birth. These were compared to women admitted to give birth that did not have influenza. Baseline characteristics, immunization status, maternal and perinatal outcomes were compared.

RESULTS

There were 405 women admitted to hospital with laboratory confirmed influenza in pregnancy: 2.7 per 10,000 maternities. Compared to 694 comparison women, women with influenza were less likely to be professionally employed (aOR 0.59, 95%CI 0.39-0.89) or immunised in the relevant season (aOR 0·59, 0·39-0·89) and more likely to have asthma (aOR 2.42, 1.30-4.49) or have had a previous pregnancy complication (aOR 2·47, 1·33-4·61). They were more likely to be admitted to intensive care (aOR 21.3, 2.78-163.1) and to have a cesarean birth (aOR 1·42, 1·02-1.98). Their babies were more likely to be admitted to neonatal intensive care (aOR 1.86, 1·01-3·42).

CONCLUSIONS

Immunization reduces the risk of hospitalisation with influenza in pregnancy which is associated with increased risk of morbidity for both the mother and baby. There is a continued need to increase awareness of safety and effectiveness of immunization in pregnancy and provision within antenatal care settings, especially for high-risk groups.

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.

Knowledge and attitudes towards influenza and influenza vaccination among pregnant women in Kenya

BACKGROUND

Influenza vaccination during pregnancy benefits mothers and children. Kenya and other low- and middle-income countries have no official influenza vaccination policies to date but are moving towards issuing such policies. Understanding determinants of influenza vaccine uptake during pregnancy in these settings is important to inform policy decisions and vaccination rollout.

METHODS

We interviewed a convenience sample of women at antenatal care facilities in four counties (Nairobi, Mombasa, Marsabit, Siaya) in Kenya. We described knowledge and attitudes regarding influenza vaccination and assessed factors associated with willingness to receive influenza vaccine.

RESULTS

We enrolled 507 pregnant women, median age was 26 years (range 15-43). Almost half (n = 240) had primary or no education. Overall, 369 (72.8%) women had heard of influenza. Among those, 288 (78.1%) believed that a pregnant woman would be protected if vaccinated, 252 (68.3%) thought it was safe to receive a vaccine while pregnant, and 223 (60.4%) believed a baby would be protected if mother was vaccinated. If given opportunity, 309 (83.7%) pregnant women were willing to receive the vaccine. Factors associated with willingness to receive influenza vaccine were mothers' belief in protective effect (OR 3.87; 95% CI 1.56, 9.59) and safety (OR 5.32; 95% CI 2.35, 12.01) of influenza vaccines during pregnancy.

CONCLUSION

Approximately one third of pregnant women interviewed had never heard of influenza. Willingness to receive influenza vaccine was high among women who had heard about influenza. If the Kenyan government recommends influenza vaccine for pregnant women, mitigation of safety concerns and education on the benefits of vaccination could be the most effective strategies to improve vaccine acceptance.

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.

Antenatal care providers' attitudes and beliefs towards maternal vaccination in Kenya

Background: Maternal immunization is known to be one of the best strategies to protect both mothers and their infants from infectious diseases. Studies have shown that healthcare providers play a critical role in implementation of maternal immunization. However, little is known about providers' attitudes and beliefs towards vaccination that can influence their vaccine recommendations, specifically in low to middle income countries (LMIC). Methods: A self-administrated knowledge, attitude and behavior (KAB) survey was provided to 150 antenatal care providers across four different regions (Nairobi, Mombasa, Marsabit, and Siaya counties) of Kenya. The research staff visited the 150 clinics and hospitals and distributed a quantitative KAB survey. Results: Nearly all of the antenatal care providers (99%) recommended tetanus maternal vaccination. Similarly, 99% of the providers agreed that they would agree to provide additional vaccinations for pregnant women and reported that they always advise their patients to get vaccinated. Between 80 and 90% of the providers reported that religious beliefs, ethnicity, cultural background and political leaders do not affect their attitude or beliefs towards recommending vaccines. Conclusions: Considering the positive responses of healthcare providers towards vaccine acceptance and recommendation, these results highlight an opportunity to work in partnership with these providers to improve coverage of maternal vaccination and to introduce additional vaccines (such as influenza). In order to achieve this, logistical barriers that have affected the coverage of the currently recommended vaccines, should be addressed as part of this partnership.

Safety, equity and monitoring: a review of the gaps in maternal vaccination strategies for Aboriginal and Torres Strait Islander women

Influenza and pertussis infections are disproportionately higher among Aboriginal and Torres Strait Islander women and their infants compared to other Australians. These infections are potentially preventable through vaccination in pregnancy; however, there is a lack of systematic monitoring and therefore knowledge of vaccine uptake, safety and effectiveness in Australia, and specifically among Aboriginal and Torres Strait Islander women. The limited data available suggest there is a lower uptake of maternal vaccination among Aboriginal and Torres Strait Islander women compared to non-Aboriginal and Torres Strait Islander women, and this review seeks to explore potential reasons and the knowledge gaps in this regard. Other key gaps include the equitable access to quality antenatal care for Aboriginal and Torres Strait Islander women; and pregnancy loss <20 weeks gestation. Furthermore, our review highlights the importance of addressing these gaps in maternal vaccination strategies in partnership with Aboriginal and Torres Strait Islander peoples.

Determining optimal community protection strategies for the influenza vaccine

Introduction: Seasonal influenza poses a major risk to the health of the population. Optimal strategies for influenza vaccination can help to reduce this risk. Areas covered: Systematic evaluations of the burden of influenza are first reviewed. Key meta-analysis, randomized trials, and observational studies are critically reviewed to provide the best estimates of the efficacy of influenza vaccine. The concept of herd effect is first introduced and this is followed by the rationale and the evidence to support herd effect that can be provided with strategic use of influenza vaccination in populations. Challenges including the effect of repeated influenza vaccination and vaccine hesitancy are reviewed. The citations were selected by the authors based on PubMed searches of the literature. Expert opinion: Efforts to develop new vaccines, including a universal vaccine, offer the best prospects for improved herd effect. Increasing uptake in new populations can increase likelihood of a herd effect.