Increasing uptake of influenza vaccine by pregnant women post H1N1 pandemic: a longitudinal study in Melbourne, Australia, 2010 to 2014

Interventions to increase vaccination against COVID-19, influenza and pertussis during pregnancy: a systematic review and meta-analysis

BACKGROUND

Pregnant women and their babies face significant risks from three vaccine-preventable diseases: COVID-19, influenza and pertussis. However, despite these vaccines' proven safety and effectiveness, uptake during pregnancy remains low.

METHODS

We conducted a systematic review (PROSPERO CRD42023399488; January 2012-December 2022 following PRISMA guidelines) of interventions to increase COVID-19/influenza/pertussis vaccination in pregnancy. We searched nine databases, including grey literature. Two independent investigators extracted data; discrepancies were resolved by consensus. Meta-analyses were conducted using random-effects models to estimate pooled effect sizes. Heterogeneity was assessed using the I2 statistics.

RESULTS

From 2681 articles, we identified 39 relevant studies (n = 168 262 participants) across nine countries. Fifteen studies (39%) were randomized controlled trials (RCTs); the remainder were observational cohort, quality-improvement or cross-sectional studies. The quality of 18% (7/39) was strong. Pooled results of interventions to increase influenza vaccine uptake (18 effect estimates from 12 RCTs) showed the interventions were effective but had a small effect (risk ratio = 1.07, 95% CI 1.03, 1.13). However, pooled results of interventions to increase pertussis vaccine uptake (10 effect estimates from six RCTs) showed no clear benefit (risk ratio = 0.98, 95% CI 0.94, 1.03). There were no relevant RCTs for COVID-19. Interventions addressed the 'three Ps': patient-, provider- and policy-level strategies. At the patient level, clear recommendations from healthcare professionals backed by text reminders/written information were strongly associated with increased vaccine uptake, especially tailored face-to-face interventions, which addressed women's concerns, dispelled myths and highlighted benefits. Provider-level interventions included educating healthcare professionals about vaccines' safety and effectiveness and reminders to offer vaccinations routinely. Policy-level interventions included financial incentives, mandatory vaccination data fields in electronic health records and ensuring easy availability of vaccinations.

CONCLUSIONS

Interventions had a small effect on increasing influenza vaccination. Training healthcare providers to promote vaccinations during pregnancy is crucial and could be enhanced by utilizing mobile health technologies.

The Interplay of Perceived Risks and Benefits in Deciding to Become Vaccinated against COVID-19 While Pregnant or Breastfeeding: A Cross-Sectional Study in Italy

The present study examined the role of the perception of risks and benefits for the mother and her babies in deciding about the COVID-19 vaccination. In this cross-sectional study, five hypotheses were tested using data from a convenience sample of Italian pregnant and/or breastfeeding women (N = 1104, July-September 2021). A logistic regression model estimated the influence of the predictors on the reported behavior, and a beta regression model was used to evaluate which factors influenced the willingness to become vaccinated among unvaccinated women. The COVID-19 vaccination overall risks/benefits tradeoff was highly predictive of both behavior and intention. Ceteris paribus, an increase in the perception of risks for the baby weighed more against vaccination than a similar increase in the perception of risks for the mother. Additionally, pregnant women resulted in being less likely (or willing) to be vaccinated in their status than breastfeeding women, but they were equally accepting of vaccination if they were not pregnant. COVID-19 risk perception predicted intention to become vaccinated, but not behavior. In conclusion, the overall risks/benefits tradeoff is key in predicting vaccination behavior and intention, but the concerns for the baby weigh more than those for the mother in the decision, shedding light on this previously neglected aspect.

Maternal influenza vaccination and child mortality: Longitudinal, population-based linked cohort study

Influenza vaccination is recommended to protect mothers and their infants from influenza. Few studies have evaluated the association between maternal influenza vaccination and child mortality. We aimed to evaluate the association between in utero exposure to seasonal inactivated influenza vaccine (IIV) and mortality among young children. This longitudinal, population-based cohort study included 191,247 maternal-child pairs in Western Australia between April 2012 and December 2017. Maternal vaccine information was obtained from a state-wide antenatal vaccination database. Mortality was defined as a record of a death registration. We used Cox proportional hazard models, weighted by the inverse-probability of treatment (vaccination), to estimate the hazard ratio of child mortality associated with in utero exposure to seasonal IIV. This study found no association between in utero exposure to seasonal IIV and mortality through age five years.

Modelling the household-level impact of a maternal respiratory syncytial virus (RSV) vaccine in a high-income setting

BACKGROUND

Respiratory syncytial virus (RSV) infects almost all children by the age of 2 years, with the risk of hospitalisation highest in the first 6 months of life. Development and licensure of a vaccine to prevent severe RSV illness in infants is a public health priority. A recent phase 3 clinical trial estimated the efficacy of maternal vaccination at 39% over the first 90 days of life. Households play a key role in RSV transmission; however, few estimates of population-level RSV vaccine impact account for household structure.

METHODS

We simulated RSV transmission within a stochastic, individual-based model framework, using an existing demographic model, structured by age and household and parameterised with Australian data, as an exemplar of a high-income country. We modelled vaccination by immunising pregnant women and explicitly linked the immune status of each mother-infant pair. We quantified the impact on children for a range of vaccine properties and uptake levels.

RESULTS

We found that a maternal immunisation strategy would have the most substantial impact in infants younger than 3 months, reducing RSV infection incidence in this age group by 16.6% at 70% vaccination coverage. In children aged 3-6 months, RSV infection was reduced by 5.3%. Over the first 6 months of life, the incidence rate for infants born to unvaccinated mothers was 1.26 times that of infants born to vaccinated mothers. The impact in older age groups was more modest, with evidence of infections being delayed to the second year of life.

CONCLUSIONS

Our findings show that while individual benefit from maternal RSV vaccination could be substantial, population-level reductions may be more modest. Vaccination impact was sensitive to the extent that vaccination prevented infection, highlighting the need for more vaccine trial data.

Early Childhood Health Outcomes Following In Utero Exposure to Influenza Vaccines: A Systematic Review

CONTEXT

Vaccination during pregnancy is an effective strategy for preventing infant disease; however, little is known about early childhood health after maternal vaccination.

OBJECTIVES

To systematically review the literature on early childhood health associated with exposure to influenza vaccines in utero.

DATA SOURCES

We searched CINAHL Plus, Embase, Medline, Scopus, and Web of Science for relevant articles published from inception to July 24, 2019.

STUDY SELECTION

We included studies published in English reporting original data with measurement of in utero exposure to influenza vaccines and health outcomes among children <5 years of age.

DATA EXTRACTION

Two authors independently assessed eligibility and extracted data on study design, setting, population, vaccines, outcomes, and results.

RESULTS

The search yielded 3647 records, of which 9 studies met the inclusion criteria. Studies examined infectious, atopic, autoimmune, and neurodevelopmental outcomes, and all-cause morbidity and mortality. Authors of 2 studies reported an inverse association between pandemic influenza vaccination and upper respiratory tract infections, gastrointestinal infections, and all-cause hospitalizations; and authors of 2 studies reported modest increased association between several childhood disorders and pandemic or seasonal influenza vaccination, which, after adjusting for confounding and multiple comparisons, were not statistically significant.

LIMITATIONS

Given the small number of studies addressing similarly defined outcomes, meta-analyses were deemed not possible.

CONCLUSIONS

Results from the few studies in which researchers have examined outcomes in children older than 6 months of age did not identify an association between exposure to influenza vaccines in utero and adverse childhood health outcomes.

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.

Midwives' knowledge, attitudes and confidence in discussing maternal and childhood immunisation with parents: A national study

INTRODUCTION

Despite the enormous benefits of childhood and maternal immunisation to individual and population health, the uptake of maternal vaccines during pregnancy remains suboptimal. Midwives are a trusted information source for parents and play an important role in the provision of immunisation information. Understanding midwives' attitudes and vaccine knowledge, along with their confidence to discuss maternal and childhood immunisation with parents, is key to reducing parental decisional conflict and achieving immunisation goals.

METHODS

An online study was conducted to investigate midwives' knowledge and attitudes towards maternal and childhood vaccination along with their confidence to answer parents' vaccine-related questions. Midwives were recruited by email via the midwifery peek body, the Australian College of Midwives.

RESULTS

A total of 359 midwives completed the online survey. The majority of midwives supported maternal (influenza 83%, pertussis 90.5%) and childhood immunisation (85.8%); however, 69.4% of respondents wanted further training about immunisation. Midwives who felt their midwifery education adequately covered immunisation were more confident advising parents about maternal (p = 0.007) and childhood immunisation (p < 0.001). Similarly, Midwives were significantly more likely to confidently advise parents about maternal (p < 0.001) and childhood immunisations (p < 0.001) if they had completed a specific immunisation training course outside of their midwifery course.

CONCLUSION

Most midwives working in Australia support vaccination. However, access to contemporary, culturally appropriate education that enables midwives to engage confidently with parents about immunisation is lacking. Education based on a women-centred approach within the pre-registration curriculum along with continuing professional development programs could enable midwives to reduce the evidence to practice gap by increasing vaccine uptake.

Vaccinating pregnant women against influenza needs to be a priority for all countries: An expert commentary

BACKGROUND

In 2012, the World Health Organization recommended influenza vaccination for all pregnant women worldwide and the prioritisation of pregnant women in national influenza vaccination programmes. Nevertheless, vaccination rates in pregnant women often remain much lower than national targets.

OBJECTIVES

To assess the benefits and risks associated with influenza infection and vaccination during pregnancy, and to consider obstacles that work against influenza vaccine uptake during pregnancy.

RESULTS

There is strong evidence that maternal and foetal outcomes can be compromised if women develop influenza infections during pregnancy. Influenza vaccines have been administered to millions of pregnant women and have demonstrated benefits in terms of disease prevention in mothers and their infants. There is a consensus amongst several recommending authorities that influenza vaccines may be safely administered during all stages of pregnancy. Healthcare professionals are recognised as the most important influencers of vaccine uptake, being well placed to recommend vaccination and directly address safety concerns.

CONCLUSIONS

Despite data supporting the value of influenza vaccination during pregnancy, vaccine uptake remains low globally. Low uptake appears to be largely due to ineffective communication with pregnant women about the risks and benefits of influenza vaccination. A graphical abstract is available online.

Influenza Vaccination and Guillain-Barré Syndrome: Reality or Fear

Guillain-Barré syndrome (GBS) is an inflammatory disorder and an acute immune-mediated demyelinating neuropathy that causes reduced signal transmissions, progressive muscle weakness, and paralysis. The etiology of the syndrome still remains controversial and uncertain. GBS can be initiated and triggered by respiratory tract infections such as influenza, and intestinal infections such as Campylobacter jejuni. In addition, there is considerable evidence suggesting links between influenza vaccination and GBS. As reported previously, the incidence of GBS in individuals receiving swine flu vaccine was about one to two cases per million. Despite the influenza vaccine efficacy, its association with an immune-mediated demyelinating process can be challenging as millions of people get vaccinated every year. In this review we will discuss the association between influenza infection and vaccination with GBS by focusing on the possible immunopathological mechanisms.

Knowledge and acceptance of influenza and pertussis vaccinations among pregnant women of low socioeconomic status in Turkey

Pregnant women and infants are at relatively high risk for influenza- and pertussis-related morbidity and mortality. Vaccination is the most important prevention strategy for both diseases. We evaluated knowledge and acceptance of influenza and pertussis vaccinations among pregnant women. We performed a cross-sectional survey of 465 pregnant women receiving prenatal care at the obstetric outpatient clinic in a tertiary medical center in Turkey between November 2015 and May 2016. We used a questionnaire investigating the knowledge of pertussis and influenza to evaluate potential influences on the acceptance or rejection of pertussis or influenza vaccinations. The acceptance rates of pertussis and influenza vaccinations were 11.2% and 19.8%, respectively. Maternal age, education level, employment status, number of gestations, and gestational age did not affect the rate of acceptance of these vaccinations. On the other hand, pregnant women who had a history of vaccination during their adolescence and in previous pregnancies were significantly more likely to accept pertussis vaccination. Knowledge about the risks of pertussis and influenza diseases for pregnant women and their children has a significant effect on vaccination acceptance. Even in low socioeconomic status groups, a recommendation for vaccinations by the primary obstetrician was significantly predictive of acceptance of both pertussis and influenza vaccination. This study revealed that the acceptance rates of pertussis and influenza vaccination among pregnant women are very low in Turkey. Healthcare worker recommendations and increased awareness about pertussis and influenza morbidity and mortality in pregnant women and infants are essential to improve the rates of vaccination acceptance during pregnancy.

Optimal timing of influenza vaccine during pregnancy: A systematic review and meta-analysis

BACKGROUND

Pregnant women have an elevated risk of illness and hospitalisation from influenza. Pregnant women are recommended to be prioritised for influenza vaccination during any stage of pregnancy. The risk of seasonal influenza varies substantially throughout the year in temperate climates; however, there is limited knowledge of how vaccination timing during pregnancy impacts the benefits received by the mother and foetus.

OBJECTIVES

To compare antenatal vaccination timing with regard to influenza vaccine immunogenicity during pregnancy and transplacental transfer to their newborns.

METHODS

Studies were eligible for inclusion if immunogenicity to influenza vaccine was evaluated in women stratified by trimester of pregnancy. Haemagglutination inhibition (HI) titres, stratified by trimester of vaccination, had to be measured at either pre-vaccination and within one month post-vaccination, post-vaccination and at delivery in the mother, or in cord/newborn blood. Authors searched PubMed, Scopus, Web of Science and EMBASE databases from inception until June 2016 and authors of identified studies were contacted for additional data. Extracted data were tabulated and summarised via random-effect meta-analyses and qualitative methods.

RESULTS

Sixteen studies met the inclusion criteria. Meta-analyses found that compared with women vaccinated in an earlier trimester, those vaccinated in a later trimester had a greater fold increase in HI titres (1.33- to 1.96-fold) and higher HI titres in cord/newborn blood (1.21- to 1.64-fold).

CONCLUSIONS

This review provides comparative analysis of the effect of vaccination timing on maternal immunogenicity and protection of the infant that is informative and relevant to current vaccine scheduling for pregnant women.

Attitudes about and access to influenza vaccination experienced by parents of children hospitalised for influenza in Australia

INTRODUCTION

In Australia, influenza hospitalises more children than any other vaccine preventable disease does. Children aged six months or older are recommended to receive annual influenza vaccines, and pregnant women are recommended vaccination to protect infants aged up to six months. However, vaccine uptake is low. This study explored influenza vaccination knowledge and behaviours of parents of children who were hospitalised for influenza, in order to inform strategies that target barriers to uptake.

METHODS

We conducted 27 semi-structured interviews with parents/caregivers during or shortly after their child's hospitalisation for laboratory-confirmed influenza in 2017. Questions were guided by the Social Ecological Model exploring all levels of influence on vaccination uptake from the intrapersonal through to policy, via the parents' perspective. Transcripts were inductively analysed. Themes were categorised into the components of the Capability-Opportunity-Motivation-Behaviour (COM-B) model.

RESULTS

20/27 children were aged six months or older; 16/20 had not received an influenza vaccine in 2017. Mothers of 4/7 infants aged less than six months were not vaccinated in pregnancy. The themes regarding barriers to influenza vaccination were: (1) Limited Capability - misinterpretations and knowledge gaps, (2) Lack of Opportunity - inconvenient vaccination pathway, missing recommendations, absence of promotion to all, and the social norm, and (3) Missing Motivation - hierarchy of perceived seriousness, safety concerns, a preference for 'natural' ways. Though most parents, now aware of the severity of influenza, intended to vaccinate their child in future seasons, some harboured reservations about necessity and safety. When parents were asked how to help them vaccinate their children, SMS reminders and information campaigns delivered through social media, schools and childcare were suggested.

CONCLUSION

Improving parents' and providers' knowledge and confidence in influenza vaccination safety, efficacy, and benefits should be prioritised. This, together with making influenza vaccination more convenient for parents, would likely raise vaccine coverage.

Knowledge and Attitudes about the Flu Vaccine among Pregnant Women in the Valencian Community (Spain)

Background and Objectives: To describe the knowledge and attitudes related to the acceptance of the flu vaccine during pregnancy in women, from two Health Departments of the Valencian Community (VC), during the 2015–2016 season, after receiving prenatal care. Materials and Methods: A prospective observational study was conducted during the annual vaccine season of women ascribed to prenatal care. A midwife offered flu vaccine advice and afterwards conducted a telephone poll of a representative sample, in order to find out the reason for accepting or rejecting the vaccine. Results: Of the 1017 expectant women who received advice about the vaccine, 77.4% (95% CI: 74.8–79.9%) declared their intention to vaccinate. After the recommendation, the vaccine coverage was 61.6%, with a percentage of accordance of 98.8% (95% CI: 98.0–99.6%) between the coverage declared and the Nominal Vaccination Registry (NVR) of the VC. Additionally, 67.2% of the expectant women were interviewed (n = 683). Most were aware of the recommendation and identified the health center and the midwife as the main sources of information. The internet was a consistent source in favor of vaccination 80.8% (n = 42). The obstetric variables (risk during the pregnancy, end of pregnancy, and feeding the newborn) did not have a statistically significant relationship with the vaccination. The women declared a high adherence to the vaccinations present in the child vaccination calendar, but rejected (31.3%) the flu vaccine, as they had not received it previously and did not want it because of their expectant state. Conclusions: The women positively evaluated the effectiveness and safety of the vaccines. However, with the flu vaccine, “not being previously vaccinated” and the “doubts about its safety” represented more than half of the reasons put forth for its rejection. Ensuring that the flu vaccine is perceived as more effective and acceptable through the messages directed towards the expectant mothers, directly through the midwives or through the communication media and social networks, will result in an increase of vaccine coverage.

Maternal immunisation: What have been the gains? Where are the gaps? What does the future hold?

The vaccination of pregnant women has enormous potential to protect not only mothers from vaccine-preventable diseases but also their infants through the passive acquisition of protective antibodies before they are able to themselves acquire protection through active childhood immunisations. Maternal tetanus programmes have been in place since 1989, and as of March 2018, only 14 countries in the world were still to reach maternal neonatal tetanus elimination status. This has saved hundreds of thousands of lives. Building on this success, influenza- and pertussis-containing vaccines have been recommended for pregnant women and introduced into immunisation programmes, albeit predominantly in resource-rich settings. These have highlighted some important challenges when additional immunisations are introduced into the antenatal context. With new vaccine candidates, such as respiratory syncytial virus (RSV) and group B streptococcus (GBS), on the horizon, it is important that we learn from these experiences, identify the information gaps, and close these to ensure safe and successful implementation of maternal vaccines in the future, particularly in low- and middle-income countries with a high burden of disease.

A Systematic Review of Barriers to Vaccination During Pregnancy in the Canadian Context

OBJECTIVE

Although vaccination in pregnancy has the potential to affect maternal and infant morbidity and mortality dramatically, uptake of recommended vaccinations in pregnancy remains low. The objective of this study was to identify barriers and facilitators of vaccination during pregnancy in Canada.

METHODS

The Medline database and the tables of contents of four relevant Canadian journals were screened to identify all studies that considered barriers and/or facilitators to vaccination during pregnancy, specifically in Canadian settings. Citations were screened, and a narrative synthesis of findings was undertaken given the heterogeneity of study design.

RESULTS

In total, 17 studies met inclusion criteria, most with a focus on the seasonal and pandemic influenza vaccines. Facilitators and barriers were identified at the level of the patient and the provider. At both levels, knowledge was an important facilitator of vaccine acceptance during pregnancy and was notably improved in studies following the 2009 pandemic H1N1 influenza outbreak compared with earlier studies. Vaccine endorsement by a prenatal care provider and clear messages of safety for the fetus emerged as key motivators. Few studies addressed system-level barriers or interventions for improving vaccine uptake during pregnancy in the Canadian setting.

CONCLUSION

Common themes have emerged from the Canadian literature addressing barriers and facilitators of vaccination during pregnancy. However, there is a paucity of literature to suggest strategies to improve the uptake of vaccination during pregnancy in Canadian settings. Further research is urgently needed given the expanding role of vaccination during routine prenatal care.

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

BACKGROUND

Influenza during pregnancy is a potentially life threatening illness. There are limited data on influenza vaccination uptake and determinants of uptake in Irish obstetric populations.

AIM

To determine the uptake of influenza vaccination during pregnancy; determinants of vaccination uptake; knowledge, attitudes, and concerns of postnatal women; and knowledge and attitudes of healthcare professionals (HCPs) surrounding vaccination.

DESIGN & SETTING

A quantitative study of postnatal women attending the Rotunda Hospital, a tertiary referral maternity hospital in Dublin, Ireland. A separate quantitative study conducted by the North Dublin City GP Training Programme surveyed GPs, pharmacists, and Rotunda Hospital clinical staff.

METHOD

A paper-based survey was distributed to postnatal women. HCPs completed the survey via the online tool Survey Monkey.

RESULTS

330 patient surveys were disseminated, with a 60.0% response rate. Of 198 responders, 109 (55.1%) were vaccinated against influenza. Non-professionals were less likely to be vaccinated (adjusted odds ratio [aOR] 0.29, 95% confidence interval [CI] = 0.09 to 0.89). Vaccination in previous pregnancy (aOR 5.2, 95% CI = 1.69 to 15.62) and information from an HCP were strongly associated with vaccination (aOR 12.8, 95% CI = 2.65 to 62.5). There was a 20.2% (n = 1180) response rate among HCPs. More GPs felt that it was their role to discuss vaccination (92.9%; n = 676), and offer to vaccinate women (91.7%; n = 666) than any other HCP.

CONCLUSION

Provision of information about the importance of vaccination against influenza and pertussis during pregnancy by HCPs and their consistent recommendations in support of vaccination were key determinants of vaccine uptake during pregnancy. The sociodemographic determinants of a woman's vaccination status should be addressed in health promotion campaigns. Education of HCPs may address knowledge gaps surrounding vaccination.

Australian caregivers' perceptions of influenza vaccination in pregnancy: A mixed methods exploration

BACKGROUND

Pregnant women and their unborn children are at high risk from both pandemic and seasonal influenza.

AIM

To explore views about influenza vaccination during pregnancy, in a pandemic and immediate post-pandemic context, among mothers and other carers of young children.

METHODS

In a mixed methods study, caregivers from 16 childcare centres in Sydney, Australia, were surveyed in November and December 2009, and interviews were conducted with caregivers from six childcare centres between June 2009 and May 2011.

FINDINGS

Emerging themes from 41 interviews conducted with mothers included: 'pregnancy as a protected state', 'risk negotiation' and 'centrality of healthcare worker interaction'. Of 972 surveys distributed, 431 were completed (a response rate of 44%). Respondents perceived pandemic influenza risks to be greater for pregnant women than for their unborn children. Only 2% (9/383) of women reported being vaccinated against swine flu during pregnancy and 45% (168/383) indicated intent to receive swine flu vaccination in a future pregnancy.

DISCUSSION

The low rates of maternal influenza vaccination revealed in this study contrast to recent gains in vaccine uptake. Vaccination decision-making in pregnancy can be complex and contextually driven for some women. Healthcare workers, including midwives, have a key role in addressing women's concerns about maternal influenza vaccination in both pandemic and interpandemic periods.

CONCLUSIONS

Policy makers need to be cognisant of women's concerns and develop resources for both pregnant women and healthcare workers as part of both future pandemic planning and seasonal vaccination efforts.

Antenatal influenza and pertussis vaccine uptake among Aboriginal mothers in Western Australia

BACKGROUND

Antenatal influenza and pertussis vaccination prevent serious disease in mothers and infants. Aboriginal individuals are at increased risk of infection yet little is known about vaccine coverage among Aboriginal mothers.

AIMS

To estimate the uptake of influenza and pertussis vaccination among pregnant Aboriginal women in Western Australia and identify barriers and enablers to vaccination.

MATERIALS AND METHODS

Four hundred Aboriginal women, aged ≥18 years, who gave birth to a live infant between April and October 2015, were randomly selected and invited to participate in telephone interviews. Of the 387 women who did not decline, 178 had a functioning phone number and 100 completed the survey. Analyses were weighted by maternal residence.

RESULTS

During pregnancy the majority of Aboriginal mothers were recommended influenza (66%; unweighted, 65/96 = 68%) and pertussis (65%; unweighted, 62/94 = 66%) vaccines, with 62% (unweighted, 56/94 = 56%) and 63% (unweighted, 60/93 = 65%) receiving the vaccinations, respectively. Almost all vaccinated women (98%) reported wanting to protect their baby as the reason for immunisation. Rural mothers were more likely than metropolitan mothers to have been vaccinated against influenza (odds ratio (OR) 4.1, 95% CI 1.7-10.2) and pertussis (OR 3.1, 95% CI 1.2-7.6). Recommendation by a healthcare provider was strongly associated with vaccine uptake (influenza: OR 15.6, 95% CI 4.9-49.5; pertussis: OR 13.3, 95% CI 4.6-38.0).

CONCLUSION

Vaccination uptake among Western Australian Aboriginal mothers is comparable with rates reported for non-Aboriginal populations worldwide. Provider recommendation is the single most important factor associated with vaccination uptake, underlining the importance of integrating vaccination into routine antenatal care.

Factors associated with uptake of influenza and pertussis vaccines among pregnant women in South Australia

BACKGROUND

Maternal immunization is an effective strategy to protect pregnant women and their infants from vaccine-preventable diseases. Despite the recommendation of maternal influenza and more recently pertussis immunization in Australia, uptake of these vaccines has been suboptimal. A midwife delivered immunization program for pregnant women at the Women's and Children's Hospital in South Australia commenced in April 2015. Monitoring the uptake of the current funded vaccine programs for pregnant women is limited. The study aimed to estimate maternal vaccine uptake and assess factors associated with influenza and pertussis vaccine uptake among pregnant women.

METHODS

This prospective study was undertaken between November 2014 and July 2016 at the Women's and Children's Hospital. Following consent, demographic details and vaccination history for South Australian pregnant women who attended the antenatal clinic were collected. A standardised self-reported survey was completed during pregnancy with a follow up telephone interview at 8-10 weeks post-delivery.

RESULTS

205 women consented and completed the self-reported survey. Of the 180 pregnant women who completed the study, 76% and 81% received maternal influenza and pertussis vaccines respectively. The adjusted odds of women receiving maternal vaccines during pregnancy were significantly higher for women delivering after the implementation of the midwife delivered program compared with women who delivered babies prior to the program for both pertussis vaccination (AOR 21.17, 95% CI 6.14-72.95; p<0.001) and influenza vaccination (AOR 5.95, 95% CI 2.13-16.61, p<0.001). Women receiving a recommendation from a health care provider and first time mothers were significantly more likely to receive influenza vaccination during pregnancy.

CONCLUSIONS

High uptake of influenza and pertussis vaccines during pregnancy can be attained with health care provider recommendation and inclusion of maternal immunization as part of standard antenatal care. A midwife delivered maternal immunization program is a promising approach to improve maternal vaccine uptake by pregnant women.

Improving rates of maternal immunization: Challenges and opportunities

OBJECTIVES

An increasing number of vaccines are recommended or are being developed for use during pregnancy to protect women, fetuses, and/or newborns. For vaccines that are already recommended, vaccine uptake is variable and well below desired target. We reviewed the literature related to factors that affect a healthcare provider's recommendation and a woman's willingness to be vaccinated during pregnancy.

DESIGN

A scoping review of published literature from 2005 to 2015 was undertaken and all relevant articles were abstracted, summarized, and organized thematically.

RESULTS

Barriers and facilitators were identified that either decreased or increased the likelihood of a healthcare provider offering and a pregnant woman accepting vaccination during pregnancy. Concern about the safety of vaccines given during pregnancy was the most often cited barrier among both the public and healthcare providers. Other barriers included doubt about the effectiveness of the vaccine, lack of knowledge about the burden of disease, and not feeling oneself to be at risk of the infection. Major facilitators for maternal immunization included specific safety information about the vaccine in pregnant women, strong national recommendations, and healthcare providers who both recommended and provided the vaccine to their patients. Systems barriers such as inadequate facilities and staffing, vaccine purchase and storage, and reimbursement for vaccination were also cited. Evidence-based interventions were few, and included text messaging reminders, chart reminders, and standing orders.

CONCLUSIONS

In order to have an effective vaccination program, improvements in the uptake of recommended vaccines during pregnancy are needed. A maternal immunization platform is required that normalizes vaccination practice among obstetrical care providers and is supported by basic and continuing education, communication strategy, and a broad range of research.

How often people google for vaccination: Qualitative and quantitative insights from a systematic search of the web-based activities using Google Trends

Nowadays, more and more people surf the Internet seeking health-related information. Information and communication technologies (ICTs) can represent an important opportunities in the field of Public Health and vaccinology. The aim of our current research was to investigate a) how often people search the Internet for vaccination-related information, b) if this search is spontaneous or induced by media, and c) which kind of information is in particular searched. We used Google Trends (GT) for monitoring the interest for preventable infections and related vaccines. When looking for vaccine preventable infectious diseases, vaccine was not a popular topic, with some valuable exceptions, including the vaccine against Human Papillomavirus (HPV). Vaccines-related queries represented approximately one third of the volumes regarding preventable infections, greatly differing among the vaccines. However, the interest for vaccines is increasing throughout time: in particular, users seek information about possible vaccine-related side-effects. The five most searched vaccines are those against 1) influenza; 2) meningitis; 3) diphtheria, pertussis (whooping cough), and tetanus; 4) yellow fever; and 5) chickenpox. ICTs can have a positive influence on parental vaccine-related knowledge, attitudes, beliefs and vaccination willingness. GT can be used for monitoring the interest for vaccinations and the main information searched.

Effect of Maternal Influenza Vaccination on Hospitalization for Respiratory Infections in Newborns: A Retrospective Cohort Study

BACKGROUND

Infants are at increased risk of hospitalization for influenza. Although vaccinating women during pregnancy has been shown to reduce the incidence of influenza infection among newborns, population-based data are limited.

METHODS

A population-based cohort of 31,028 mothers and singleton infants were included in the analysis. Hospitalizations with a principal diagnosis or additional diagnoses consistent with severe respiratory illness occurring during the 2012 and 2013 southern hemisphere influenza seasons were identified using a state-wide hospital discharge database. Newborns were defined as "maternally vaccinated" if the mother received influenza vaccine ≥14 days before delivery. Cox regression models were used to estimate adjusted hazard ratios for hospitalization.

RESULTS

A total of 3169 infants were maternally vaccinated and 27,859 were unvaccinated; 732 hospitalizations were identified, 528 (69%) of which were for bronchiolitis. There were 21.9 hospitalizations per 100,000 person days among maternally vaccinated infants and 30.2 hospitalizations per 100,000 person days among unvaccinated infants. Maternally vaccinated infants were 25% less likely to be hospitalized for an acute respiratory illness during influenza season compared with unvaccinated infants (adjusted hazard ratio: 0.75, 95% confidence interval: 0.56-0.99, P = 0.04). Vaccinations administered in the third trimester were associated with a 33% reduction in the risk of newborn hospitalization (adjusted hazard ratio: 0.67, 95% confidence interval: 0.47-0.95, P = 0.03). No such reduction was identified for vaccinations administered earlier in pregnancy.

CONCLUSIONS

Maternal influenza vaccination was associated with a reduction in the incidence of hospital admission for acute respiratory illness among infants <6 months of age. These data suggest that vaccination during third trimester may provide optimal benefit to the newborn.

Effectiveness of seasonal trivalent influenza vaccination against hospital-attended acute respiratory infections in pregnant women: A retrospective cohort study

BACKGROUND

Pregnant women are at risk of serious influenza infection. Although previous studies indicate maternal influenza vaccination can prevent hospitalisation in young infants, there is limited evidence of the effect in mothers.

METHODS

A cohort of 34,701 pregnant women delivering between 1 April 2012 and 31 December 2013 was created using birth records. Principal diagnosis codes from hospital emergency department (ED) and inpatient records were used to identify episodes of acute respiratory illness (ARI) during the 2012 and 2013 southern hemisphere influenza seasons. Cox regression models were used to calculate adjusted hazard ratios (aHRs) by maternal vaccination status, controlling for Indigenous status, socioeconomic level, medical conditions, and week of delivery.

RESULTS

3,007 (8.7%) women received a seasonal influenza vaccine during pregnancy. Vaccinated women were less likely to visit an ED during pregnancy for an ARI (9.7 visits per 10,000 person-days vs. 35.5 visits per 10,000 person-days; aHR: 0.19, 95% CI: 0.05-0.68). Vaccinated women were also less likely to be hospitalised with an ARI compared to unvaccinated women (16.2 hospitalisations per 10,000 person-days vs. 34.0 hospitalisations per 10,000 person-days; aHR: 0.35, 95% CI: 0.13-0.97).

CONCLUSIONS

Influenza vaccination during pregnancy was associated with significantly fewer hospital attendances for ARI in pregnant women.

A global survey of adverse event following immunization surveillance systems for pregnant women and their infants

Strengthening antenatal care as a platform for maternal immunization is a priority of the World Health Organization (WHO). Systematic surveillance for adverse events following immunization (AEFI) in pregnancy is needed to identify vaccine safety events. We sought to identify active and passive AEFI surveillance systems for pregnant women and infants. Representatives from all National Pharmacovigilance Centers and a convenience sample of vaccine safety experts were invited to complete a 14-item online survey in English, French or Spanish. The survey captured maternal immunization policies, and active and passive AEFI surveillance systems for pregnant women and infants in respondents' countries. The analysis was descriptive. We received responses from 51/185 (28%) invited persons from 47/148 (32%) countries representing all WHO regions, and low, middle and high-income countries. Thirty countries had national immunization policies targeting pregnant women. Eleven countries had active surveillance systems to detect serious AEFI in pregnant women and/or their infants, including six low and middle-income countries (LMIC). Thirty-nine countries had passive surveillance systems, including 23 LMIC. These active and passive surveillance programs cover approximately 8% and 56% of the worldwide annual birth cohort, respectively. Data from one active and four passive systems have been published. We identified 50 active and passive AEFI surveillance systems for pregnant women and infants, but few have published their findings. AEFI surveillance appears to be feasible in low and high resource settings. Further expansion of AEFI surveillance for pregnant women and sharing of vaccine safety information will provide additional evidence in support of maternal immunization policies.

A prospective cohort study assessing the reactogenicity of pertussis and influenza vaccines administered during pregnancy

BACKGROUND

Pertussis vaccination during pregnancy can prevent 91% of infant infections. In 2015, antenatal pertussis vaccination programs were introduced across Australia.

METHODS

To monitor the safety of this program, pregnant women who received trivalent influenza vaccine (TIV) and/or diphtheria-tetanus-acellular pertussis vaccine (dTpa) were surveyed by text message seven days post-vaccination about possible adverse events following immunization (AEFI). Univariate logistic regression models were used to calculate the odds of reporting an AEFI following dTpa compared to TIV. Similar analyses were used to compare AEFI reported by women who received a previous dose of dTpa in 2011/2012 as part of a state-wide cocooning program.

RESULTS

Of 5155 women, 4347 (84.3%) replied; 10.8% indicated they experienced an AEFI. There was no difference in the proportion of women who reported any reaction by vaccine; however, women who received dTpa were more likely to report a local reaction than women who received TIV (7.1% and 3.2%, respectively; OR: 2.29; 95% CI: 1.61-3.26). There was evidence suggesting local reactions were more common among women with a previous dose of dTpa (11.4%) compared to women with no previous dose (6.0%; OR: 2.00; 95% CI: 0.95-4.25); 11 (0.3%) women reported attending a hospital emergency department. Subsequent follow-up indicated symptoms resolved and mother and infant were healthy. There was no difference in the proportion of women attending hospital by vaccine (p > 0.05).

DISCUSSION

Data on systemic and local reactions following receipt of TIV and dTpa during pregnancy support the safety of antenatal vaccination.

Trends in seasonal influenza vaccine uptake during pregnancy in Western Australia: Implications for midwives

BACKGROUND

Antenatal influenza vaccination is an important public health intervention for preventing serious illness in mothers and newborns, yet uptake remains low.

AIM

To evaluate trends in seasonal influenza vaccine coverage and identify determinants for vaccination among pregnant women in Western Australia.

METHODS

We conducted an annual telephone survey in a random sample of post-partum women who delivered a baby in Western Australia between 2012 and 2014. Women were asked whether influenza vaccination was recommended and/or received during their most recent pregnancy; women were also asked why or why they were not immunised.

FINDINGS

Between 2012 and 2014, influenza vaccine coverage increased from 22.9% to 41.4%. Women who reported receiving the majority of their antenatal care from a private obstetrician were significantly more likely to have influenza vaccination recommended to them than those receiving the majority of their care from a public antenatal hospital or general practitioner (p<0.001). In 2014, the most common reason women reported for accepting influenza vaccination was to protect the baby (92.8%) and the most common reason for being unimmunised was lack of a healthcare provider recommendation (48.5%).

DISCUSSION

Antenatal influenza vaccination uptake is increasing, but coverage remains below 50%. A recommendation from the principal care provider is an important predictor of maternal influenza vaccination.

CONCLUSION

Antenatal care providers, including midwives, have a key role in providing appropriate information and evidence-based recommendations to pregnant women to ensure they are making informed decisions. Consistent recommendations from antenatal care providers are critical to improving influenza vaccine coverage in pregnant women.