Vaccine decision-making begins in pregnancy: Correlation between vaccine concerns,intentions and maternal vaccination with subsequent childhood vaccine uptake

IntroductionMaternal and childhood vaccine decision-making begins prenatally. Amongst pregnant Australian women we aimed to ascertain vaccine information received, maternal immunisation uptake and attitudes and concerns regarding childhood vaccination. We also aimed to determine any correlation between a) intentions and concerns regarding childhood vaccination, (b) concerns about pregnancy vaccination, (c) socioeconomic status (SES) and (d) uptake of influenza and pertussis vaccines during pregnancy and routine vaccines during childhood.MethodsWomen attending public antenatal clinics were recruited in three Australian states. Surveys were completed on iPads. Follow-up phone surveys were done three to six months post delivery, and infant vaccination status obtained via the Australian Childhood Immunisation Register (ACIR).ResultsBetween October 2015 and March 2016, 975 (82%) of 1184 mothers consented and 406 (42%) agreed to a follow up survey, post delivery. First-time mothers (445; 49%) had significantly more vaccine concerns in pregnancy and only 73% had made a decision about childhood vaccination compared to 89% of mothers with existing children (p-value < 0.001). 66% of mothers reported receiving enough information during pregnancy on childhood vaccination. In the post delivery survey, 46% and 82% of mothers reported receiving pregnancy influenza and pertussis vaccines respectively. The mother's degree of vaccine hesitancy and two attitudinal factors were correlated with vaccine uptake post delivery. There was no association between reported maternal vaccine uptake or SES and childhood vaccine uptake.ConclusionFirst time mothers are more vaccine hesitant and undecided about childhood vaccination, and only two thirds of all mothers believed they received enough information during pregnancy. New interventions to improve both education and communication on childhood and maternal vaccines, delivered by midwives and obstetricians in the Australian public hospital system, may reduce vaccine hesitancy for all mothers in pregnancy and post delivery, particularly first-time mothers.     

我国6个省份全人群流感疫苗接种及认知情况调查

目的 了解调查地区全年龄组人群流感预防知识的认知及流感疫苗接种情况，探索影响流感疫苗接种的相关因素。方法 采用横断面调查设计，选择北京市、内蒙古自治区、上海市、广东省、云南省和甘肃省6个省份，通过12320卫生热线采用随机数字表拨打电话的抽样方法，于2018年3-5月开展全年龄组人群的流感防控知识、流感疫苗接种情况的电话调查，调查估计样本量为9 438人。结果 本调查应答率为46.4%（10 045/21 658），10 045名调查对象中，"流感和普通感冒有区别"的知晓率为75.3%（7 564/10 045），"流感病毒会引起严重后果"的知晓率为82.0%（8 241/10 045）。出现流感样症状后采取频繁洗手、戴口罩和自我隔离的健康行为率分别为80.4%（7 936/9 873）、75.8%（7 506/9 899）和73.6%（7 228/9 822）。最近1年流感疫苗接种率为5.7%（570/10 037）。最近1年流感疫苗接种率的相关多因素logistic回归分析结果显示，调查对象来自甘肃省或北京市、职业是医务人员或全日制学生、调查对象共同居住人数≥ 2人、出现流感样症状后戴口罩，最近1年流感疫苗接种率相对较高。结论 6个省份调查对象流感相关知识的知晓率、出现流感相关症状后的健康行为率和最近1年流感疫苗接种率均有待进一步提高。应加强流感预防知识和疫苗接种的健康教育，探索流感疫苗免费接种策略。     

Coverage of recommended vaccines during pregnancy in Flanders,Belgium. Fairly good but can we do better?

BackgroundIn Flanders, Belgium, pertussis vaccination is recommended since 2013 and available free-of-charge in every pregnancy between 24 and 32 weeks of gestation. Influenza vaccination is recommended for more than 10 years with a co-payment system in the second or third trimester of pregnancy, when pregnancy coincides with the influenza season. This study aims to estimate the coverage of pertussis and influenza vaccination during pregnancy in 2016 and to determine predictors for missing vaccination.MethodsPostpartum women were visited at home for a vaccination coverage survey using an Expanded Program on Immunization (EPI)-based two-stage cluster sampling design. Predictors for missed vaccination were identified using a multiple logistic regression model.ResultsAmong 481 participating women, 69.3% were vaccinated against pertussis and 47.2% were vaccinated against influenza. Moreover, 65.3% of pertussis vaccine recipients and 96.9% of influenza vaccine recipients were vaccinated within the recommended gestational window.Surprisingly, among women who were completely informed (i.e. on disease-associated risks, maternal vaccination costs and recommendations), still 12.4% were unvaccinated against pertussis and 23.9% against influenza.In the final models, the only common predictor of missing maternal pertussis and influenza vaccination was multiparity. Significant predictors of maternal pertussis vaccination were family income (less likely if unknown or low (< €3000) than if moderate (€3001-€4000)) and hospital of delivery (less likely if >800 annual deliveries than <800). Significant predictors of maternal influenza vaccination, though with less straight-forward associations, were maternal ethnicity and educational level, involvement of a gynaecologist in pregnancy follow-up, and characteristics of the hospital of delivery.ConclusionIn Flanders, more than two-third of pregnant women receives pertussis vaccination but less than half of them receives the influenza vaccine. Further improvement for both maternal vaccination programs can be achieved by targeting the underserved populations and diminishing vaccination hurdles.     

Psychosocial determinants of pertussis and influenza vaccine uptake in pregnant women: A prospective study

ObjectiveTo identify the psychosocial factors influencing women’s uptake and willingness to receive pertussis and influenza vaccine during pregnancy.MethodsThe study population comprised 1364 healthy nulliparous pregnant women who participated in a prospective cohort study at two obstetric hospitals in South Australia between 2015 and 2017. Information on women's vaccination status, sociodemographic, lifestyle and psychological state were collected at 9–16 weeks’ gestation and medical case notes were checked post-delivery to verify the reported vaccination status. Poisson regression models were used to estimate the crude and adjusted prevalence ratios (aPRs) to identify psychosocial factors influencing uptake of vaccination during pregnancy.ResultsWillingness to receive the recommended maternal vaccines was high (90%). Overall, 79% and 48% received maternal pertussis and influenza vaccines respectively. There was no evidence to support the influence of psychosocial factors on women’s willingness to receive immunization during pregnancy. High levels of anxiety (aPR 0.98, 95% CI: 0.87–1.09) was not associated with uptake of maternal pertussis vaccine. However, elevated depressive symptoms (aPR 1.14, 95% CI: 1.00–1.30) and very high-perceived stress during pregnancy were significantly associated with receipt of pertussis vaccination (aPR 0.87; 95% CI 0.76–0.99). Women with mild depressive symptoms (aPR 1.21, 95% CI 1.00–1.44) and mild anxiety symptoms (aPR 1.21, 95% CI: 0.99–1.48) were more likely to receive influenza vaccine during pregnancy (aPR 1.27, 95% CI: 1.08–1.49). A history of major depressive disorder was independently associated with receipt of pertussis (aPR 1.16, 95% CI 1.06–1.26) and influenza vaccination during pregnancy (aPR 1.32; 95% CI 1.14–1.58).ConclusionRegardless of psychosocial factors, most women reported a positive willingness to receive the recommended vaccinations during pregnancy. However, psychosocial factors influenced the uptake of pertussis and influenza vaccines during pregnancy. Psychosocial factors should be taken into consideration in designing interventions and implementation of maternal pertussis and influenza immunization programs.     

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

BackgroundPertussis vaccination during pregnancy can prevent 91% of infant infections. In 2015, antenatal pertussis vaccination programs were introduced across Australia.MethodsTo 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.ResultsOf 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).DiscussionData on systemic and local reactions following receipt of TIV and dTpa during pregnancy support the safety of antenatal vaccination.     

Community awareness and predictors of uptake of pertussis booster vaccine in South Australian adults

ObjectivePertussis is a highly virulent vaccine preventable disease that remains a global challenge. This study aimed to assess community knowledge of pertussis infection as well as awareness and uptake of adult pertussis booster vaccine.MethodsA cross-sectional survey was conducted of randomly selected households in South Australia by Computer Assisted Telephone Interviews in 2011. Survey data were weighted to the age, gender and geographical area profile of the population.ResultsFrom 3124 randomly sampled contactable households, 1967 interviews were conducted (participation rate 63%) with individuals aged 18–93 years, including 608 parents of children aged <18 years. The majority of respondents (97%) had heard of pertussis (whooping cough) and 18% reported that a household member had previously contracted whooping cough infection. Most respondents considered whooping cough to be highly contagious (73%) and severe for infants (89%). Over half (51%) of those surveyed were aware that family members commonly transmit pertussis to infants. Despite high knowledge, pertussis vaccine uptake was low, with only 10% of respondents reporting pertussis vaccination in the previous five years. Whilst 61% of respondents were aware of the availability of an adult pertussis booster vaccine, only 8% (n = 154) reported their Family Physician had discussed it with them. If provided free, 77% agreed that they would be more likely to accept a booster pertussis vaccination. Independent predictors of recent pertussis vaccination included higher education, larger household size, perception of greater disease severity for infants and discussion with a Family Physician about pertussis vaccination.ConclusionsWhilst knowledge regarding transmission and severity of Bordetella pertussis was high, uptake of pertussis vaccination for adults is remarkably low amongst the South Australian community. Improved awareness regarding the availability of a booster pertussis vaccine through Family Physicians and/or provision of funded pertussis vaccination for adults has the potential to improve pertussis vaccine coverage.     

Influenza vaccine effectiveness in hospitalised Hong Kong children: Feasibility of estimates from routine surveillance data

BackgroundHong Kong has a high burden of influenza hospitalisation. This study estimated influenza vaccine effectiveness in hospitalised Hong Kong children aged 6 months to below 6 years using data potentially obtainable from routine surveillance sources.MethodsThis ‘test-negative’ case-control study was conducted over two summer and one winter influenza seasons in five public Hong Kong hospitals during 2015 and 2016. Patients admitted for febrile and/or respiratory-associated illnesses who met inclusion criteria were invited to participate. Case-patients were respiratory-associated admissions with nasopharyngeal aspirate or nasopharyngeal swab specimens obtained during the first 48 h of hospitalisation that tested positive for influenza A or B, whereas control-patients were those with specimens that tested negative for both influenza A and B. Reliability of a routinely collected influenza immunisation status form was evaluated. Vaccine effectiveness for administration of full or partial series of influenza vaccination was calculated as 1 minus the odds ratio for influenza vaccination history for case-patients versus control-patients.Results2900 eligible subjects had influenza vaccination status available. A simple record form, designed to collect upon admission information on influenza vaccination status, was found to be reliable when compared to confirmed vaccination status from immunisation records and guardians’ self-reports. Influenza vaccine effectiveness for preventing influenza A or B hospitalisation in children aged from 6 months to below 6 years during the period June 2015 to November 2016 was 68% (95% confidence interval [CI]: 55%, 77%) from unconditional analyses and 64% (95% CI: 46%, 75%) from conditional analyses.ConclusionsSeasonal influenza vaccine was effective in preventing hospitalisation from influenza A or B in young Hong Kong children during 2015 and 2016. As influenza vaccination status is not currently routinely recorded, implementation of an influenza immunisation status form in all paediatric wards, and centralising the data in Hong Kong's central computerised database, could provide real-time monitoring of influenza vaccine effectiveness.     

Low uptake of influenza vaccine among university students: Evaluating predictors beyond cost and safety concerns

IntroductionAnnual influenza vaccine coverage for young adults (including college students) remains low, despite a 2011 US recommendation for annual immunization of all people 6 months and older. College students are at high risk for influenza morbidity given close living and social spaces and extended travel during semester breaks when influenza circulation typically increases. We evaluated influenza vaccine uptake following an on-campus vaccine campaign at a large, public New York State university.MethodsConsecutive students visiting the University Health Center were recruited for a self-administered, anonymous, written survey. Students were asked about recent influenza vaccination, barriers to influenza vaccination, and willingness to get vaccinated to protect other vulnerable individuals they may encounter. Frequencies and proportions were evaluated.ResultsOf 653 students approached, 600 completed surveys (92% response proportion); respondents were primarily female (61%) and non-Hispanic white (59%). Influenza vaccine coverage was low (28%). Compared to coverage among non-Hispanic white students (30%), coverage was similar among Hispanic (30%) and other race/ethnicity students (28%) and lowest among non-Hispanic black students (17%). Among the unvaccinated, the most commonly selected vaccination barriers were “Too lazy to get the vaccine” (32%) and “Don’t need the vaccine because I’m healthy” (29%); 6% of unvaccinated students cited cost as a barrier. After being informed that influenza vaccination of young, healthy people can protect other vulnerable individuals (e.g., infants, elderly), 71% of unvaccinated students indicated this would increase their willingness to get vaccinated.ConclusionsInfluenza vaccine uptake among college students is very low. While making vaccine easily obtained may increase vaccine uptake, college students need to be motivated to get vaccinated. Typically healthy students may not perceive a need for influenza vaccine. Education about vaccinating healthy individuals to prevent the spread of influenza to close contacts, such as vulnerable family members, may provide this motivation to get vaccinated.     

Intention to accept pertussis vaccine among pregnant women in Karachi,Pakistan

BackgroundMaternal immunization against pertussis is a potential strategy to protect young infants from severe disease. We assessed factors associated with intention to accept pertussis vaccination among pregnant women in Karachi, Pakistan.MethodsWe conducted a cross-sectional survey between May and August 2013 in pregnant women who visited healthcare centers in urban slums of Karachi city. Women completed a survey examining socio-demographic factors, vaccination history, knowledge on pertussis disease, perception of vaccine recommendation sources, and potential influences on vaccine decision-making.ResultsOf the 283 participants, 259 (92%) provided their intention to either accept or decline pertussis vaccination. Eighty-three percent women were willing to accept the pertussis vaccine if offered during pregnancy. About half (53%) of the participants had ever heard of pertussis disease. Perceptions of pertussis vaccine efficacy, safety, and disease susceptibility were strongly associated with intention to accept pertussis vaccine (p < 0.01). Healthcare providers, Ministry of Health, and mass media were considered as highly reliable sources of vaccine recommendation and associated with intention to accept antenatal pertussis vaccination (p < 0.001). Healthcare provider recommendation was a common reason cited by respondents for pregnant women to accept antenatal pertussis vaccination (p = 0.0005). However, opinion of primary decision-makers in the family (husbands and in-laws) was a crucial reason cited by respondents for pregnant women to reject pertussis vaccination in pregnancy (p = 0.003).ConclusionAntenatal pertussis vaccination initiatives in South Asia should strongly consider inclusion of family members, healthcare providers, national health ministries, and mass media to help implement new vaccination programs.     

What determines uptake of pertussis vaccine in pregnancy? A cross sectional survey in an ethnically diverse population of pregnant women in London

IntroductionFollowing the major outbreak of pertussis and 14 infant deaths across England in 2012, the Department of Health (DH) introduced the UK's first maternal pertussis vaccination programme. Data published by Public Health England (PHE) suggest uptake of the vaccine varies considerably across the country. The reasons for this heterogeneity need to be addressed to optimise the impact of the programme.ObjectiveTo assess uptake of antenatal pertussis and influenza vaccine in a leading NHS Trust in London and to explore awareness and attitudes of pregnant women towards the pertussis vaccination programme.DesignA cross sectional survey was conducted in an ethnically diverse group of 200 pregnant women accessing antenatal care at Imperial Healthcare NHS Trust. Quantitative data was tabulated and content analysis was carried out on the free text. Qualitative data was divided into themes for accepting or declining the vaccine.ResultsAwareness of the programme was 63% (126/200) with actual uptake of the vaccine only 26.0% (52/200). Women had received information from multiple sources, primarily General Practitioners (GP) and midwives. 34.0% (68/200) of women were offered the vaccine at their GP practice, only 24% reported a meaningful discussion with their GP about it. Uptake differed by up to 15.0% between ethnicities. Qualitative data showed that uptake could be significantly enhanced if vaccination was recommended by a familiar healthcare professional. Feeling uninformed, lack of professional encouragement and uncertainties of risk and benefit of the vaccine were the greatest barriers to uptake.ConclusionVaccine uptake in this cohort of pregnant women was poor. Understanding the target audience and engaging with key groups who influence women's decision-making is essential. Knowledgeable health care professionals need to recommend the vaccine and provide accurate and timely information to increase success of this important programme.     

Influenza vaccination hesitancy and its determinants among elderly in China: A national cross-sectional study

BackgroundThe Chinese elderly face a significant threat from seasonal influenza, owing to the consistently low vaccination coverage. This study investigated the prevalence and determinants of influenza vaccination hesitancy among the Chinese elderly.MethodsIn 2019, 3849 elderly individuals from 10 provinces in China were recruited in a cross-sectional survey. Multinomial logistic regression was applied to investigate the determinants of influenza vaccination hesitancy.ResultsAmong the elderly respondents, 37.18% expressed some degree of hesitancy towards influenza vaccination: 19.28% were hesitant, and 17.90% refused influenza vaccination, including 19.28% acceptors with doubts and 17.90% refusers. Only 39.10% of the respondents considered themselves as the priority group for influenza vaccination, and 13.93% reported receiving a recommendation for vaccination from healthcare workers. Respondents with higher education levels and from urban areas had significantly higher odds of vaccine hesitancy than their counterparts. Confidence in the safety of vaccines was negatively associated with vaccine hesitancy, but confidence in vaccine efficacy had no such association. Respondents who perceived themselves as highly susceptible to influenza (AOR = 0.85; 95 %CI = 0.77–0.93) and those aware of the elderly as a priority group for influenza vaccination (AOR = 0.51; 95 %CI = 0.41–0.64) had a significantly lower odds of being refusers.ConclusionThis study found a high prevalence of hesitancy towards influenza vaccination among the Chinese elderly, especially well-educated and urban-dwelling respondents. The government should address vaccine hesitancy through culturally appropriate communication, subsidies for vaccination, and actively promoting vaccines through primary care professionals.     

Pertussis and influenza immunisation coverage of pregnant women in New Zealand

BackgroundImmunisation is an important public health policy and measuring coverage is imperative to identify gaps and monitor trends. New Zealand (NZ), like many countries, does not routinely publish coverage of immunisations given during pregnancy. Therefore, this study examined pregnancy immunisation coverage of all pregnant NZ women between 2013 and 2018, and what factors affected uptake.MethodsA retrospective cohort study of pregnant women who delivered between 2013 and 2018 was undertaken using administrative datasets. Maternity and immunisation data were linked to determine coverage of pertussis and influenza vaccinations in pregnancy. Generalised estimating equations were used to estimate the odds of receiving a vaccination during pregnancy.ResultsFrom 2013 to 2018 data were available for 323,622 pregnant women, of whom 21.7% received maternal influenza immunisations and 25.7% maternal pertussis immunisations. Coverage for both vaccines increased over time, pertussis increased from 10.2% to 43.6% and influenza from 11.2% to 30.8%. The odds of being vaccinated, with either vaccine, during pregnancy increased with increasing age and decreasing deprivation. Compared to NZ European or Other women, Māori and Pacific women had lower odds of receiving a maternal pertussis (OR:0.55, 95% CI: 0.54, 0.57; OR:0.60, 95% CI: 0.58, 0.62, respectively) and influenza (OR: 0.69, 95% CI: 0.67, 0.71; OR:0.90, 95% CI: 0.87, 0.94, respectively) immunisations during pregnancy. Women were also more likely to be vaccinated against pertussis if they received antenatal care from a General Practitioner or Obstetrician compared to a Midwife. A similar pattern was seen for influenza vaccination.ConclusionGaps in maternal coverage for pertussis and influenza exist and work is needed to reduce immunisation inequities.     

Effectiveness of inactivated influenza vaccine in children by vaccine dose, 2013–18

ObjectivesWe assessed the vaccine effectiveness (VE) of inactivated influenza vaccine (IIV) by vaccine dose in children aged 6 months to 12 years for whom two doses are recommended in Japan to ascertain the appropriate vaccine doses.MethodsVE was assessed according to a test-negative case-control design based on rapid influenza diagnostic test (RIDT) results. Children aged 6 months to 12 years with a fever ≥38 °C who had received an RIDT in outpatient clinics of 24 hospitals were enrolled for all five seasons since 2013/14. VE by vaccine dose (none vs. once or twice, and once vs. twice) was analyzed.ResultsIn the dose analysis, 20,033 children were enrolled. Both one- and two-dose regimens significantly reduced cases in preventing any influenza, influenza A, and influenza B, but there was no significant difference in adjusted VE between one- and two-dose regimens overall (adjusted OR, 0.560 [95% CI, 0.505–0.621], 0.550 [95% CI, 0.516–0.586]), 0.549 [95% CI, 0.517–0.583], and 1.014 [95% CI, 0.907–1.135], for none vs. once, none vs. twice, none vs. once or twice, and once vs. twice for any influenza, respectively). Both one- and two-dose regimens significantly reduced cases with any influenza and influenza A every season. Also, both regimens significantly reduced cases of any influenza, influenza A, and influenza B among children aged 1–12 years, especially among those aged 1–5 years. In the 2013/14, 2015/16, and 2016/17 seasons, however, only the two-dose regimen was significantly effective in preventing influenza B. Both one- and two-dose regimens significantly reduced cases involving hospitalization due to any influenza and influenza A.ConclusionsBoth one- and two-doses regimens of IIV were effective in preventing influenza for children aged 6 months to 12 years. The two-dose regimen was more effective against influenza B in some seasons.     

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

BackgroundInfluenza 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.MethodsWe 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.ResultsWe 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.ConclusionApproximately 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.     

Value of an in-depth analysis of unpublished data on the safety of influenza vaccines in pregnant women

BackgroundUnpublished data can sometimes provide valuable information on the safety of biologic products.MethodsWe assessed information potentially available from regulatory authorities, manufacturers, and public health agencies. We explored 4 recently established vaccine registries, reviewed package inserts from 99 influenza vaccines, and contacted vaccine manufacturers and regulatory agencies for data on influenza vaccine safety in pregnant women.ResultsThe vaccine registries did not have sufficient data to analyze and there are problems with the quality of the information. The majority of package inserts provided no product-specific safety information for pregnant women, especially in less developed countries. The majority of available data come from reports gathered from passive adverse event reporting systems in the general population and reports of women enrolled in clinical trials of influenza vaccines who became pregnant at various times before or after receiving influenza vaccine. The information was not collected in a systematic manner, there are inconsistencies in the follow up of pregnant women and the available information about pregnancy outcomes. Considerable resources would be needed to systematically identify all of the information, try to obtain missing follow up information, and conduct analyses. There would be substantial limitations to any attempt to conduct a systematic analysis.ConclusionsThe value of trying to analyze unpublished data on the safety of influenza vaccine in pregnancy is limited and would require considerable resources to thoroughly investigate. Expanding efforts to identify and review unpublished data regarding the safety of influenza vaccines in pregnancy is not likely to produce information of high scientific value or information that could not be identified from publications and other publically available data.     

Flu and pertussis vaccination during pregnancy in Geneva during the COVID-19 pandemic: A multicentric,prospective, survey-based study

ObjectiveTo determine pertussis and influenza vaccination coverage during pregnancy among women delivering in all the maternities of Geneva (Switzerland), during the COVID-19 pandemic.MethodsAll women delivering in all the maternity centres of the canton of Geneva from 1st November 2020 to 30th November 2020 (beginning of the flu vaccination season) and from 8th March 2021 to 7th April 2021 (end of the flu vaccination season) had their records checked upon admission to the labour ward regarding pertussis and influenza vaccination during pregnancy. Reasons for non-vaccination were recorded. Univariate and multivariate analyses were done to identify predictors of vaccine uptake.Results951 women delivered in Geneva during the two study periods, of which 950 were included in the study. 86.2% were vaccinated against pertussis, with no significant difference between the study periods (87.5% vs 85% at the beginning and end of the flu vaccination season respectively). 49.8% were vaccinated against influenza, with no significant difference between the study periods (48.8% vs 50.7% beginning and end of the flu vaccination season respectively). The influenza vaccine was 5 times more likely not to be proposed (8.9% vs. 1.7%) and 3 times more likely to be refused (26.6% vs. 8%) than the pertussis vaccine. Main reason for refusal was a lack of maternal desire for both vaccines, but not vaccine fear. Maternal parity ≥ 1 was significantly associated with pertussis vaccine uptake at univariate analysis. Women were significantly more likely to accept the influenza vaccine if they had a university degree or if they did not deliver in a midwife-only run delivery unit in both univariate and multivariate analysis.ConclusionsIn Geneva, most gynaecologists offer pertussis immunization during antenatal care and uptake is high, but more efforts must be done to increase influenza vaccination coverage. Education level impacts maternal flu vaccination uptake, but other social disparities did not.     

Intention to accept Bordetella pertussis booster vaccine during pregnancy in Mexico City

Objective

Adult booster vaccination against pertussis can help prevent severe infections in young infants. We examined influences on intention to accept pertussis booster vaccination among pregnant women in Mexico City.

Methods

We conducted a cross-sectional survey, recruiting convenience samples of pregnant women receiving prenatal care from three public healthcare centers between March and May 2012. Our primary outcome was intention to accept pertussis vaccination during pregnancy. We examined socio-demographic factors, vaccination history, pertussis knowledge, perceptions of vaccine information sources, and other potential influences on vaccine decision-making.

Results

A total of 402 pregnant women agreed to participate, of which 387 (96%) provided their intention to accept or decline pertussis vaccination. Among respondents, 57% intended to accept a pertussis booster vaccine if offered, but only 16% had ever heard of pertussis, and only 2% knew someone who had contracted this disease. Over 80% of respondents would accept pertussis vaccination if recommended by an obstetrician-gynecologist. The most frequently selected reasons to refuse pertussis vaccination were concerns that the vaccine might harm the unborn baby or pregnant woman. In multivariate analysis, rating doctors and nurses as good sources of vaccine information, and having ever heard of pertussis, were independently associated with intention to accept pertussis vaccination.

Conclusions

Promoting patient awareness about pertussis disease and vaccine safety, and encouraging general practitioners, nurses and obstetricians to recommend pertussis booster vaccine, may increase vaccine uptake among pregnant women.     

Active SMS-based influenza vaccine safety surveillance in Australian children

IntroductionAustralia’s novel, active surveillance system, AusVaxSafety, monitors the post-market safety of vaccines in near real time. We analysed cumulative surveillance data for children aged 6 months to 4 years who received seasonal influenza vaccine in 2015 and/or 2016 to determine: adverse event following immunisation (AEFI) rates by vaccine brand, age and concomitant vaccine administration.MethodsParent/carer reports of AEFI occurring within 3 days of their child receiving an influenza vaccine in sentinel immunisation clinics were solicited by Short Message Service (SMS) and/or email-based survey. Retrospective data from 2 years were combined to examine specific AEFI rates, particularly fever and medical attendance as a proxy for serious adverse events (SAE), with and without concomitant vaccine administration. As trivalent influenza vaccines (TIV) were funded in Australia’s National Immunisation Program (NIP) in 2015 and quadrivalent (QIV) in 2016, respectively, we compared their safety profiles.Results7402 children were included. Data were reported weekly through each vaccination season; no safety signals or excess of adverse events were detected. More children who received a concomitant vaccine had fever (7.5% versus 2.8%; p < .001). Meningococcal B vaccine was associated with the highest increase in AEFI rates among children receiving a specified concomitant vaccine: 30.3% reported an AEFI compared with 7.3% who received an influenza vaccine alone (p < .001). Reported fever was strongly associated with medical attendance (OR: 42.6; 95% Confidence Interval (CI): 25.6–71.0). TIV and QIV safety profiles included low and expected AEFI rates (fever: 4.3% for TIV compared with 3.2% for QIV (p = .015); injection site reaction: 1.9% for TIV compared with 3.0% for QIV (p < .001)). There was no difference in safety profile between brands.DiscussionActive participant-reported data provided timely vaccine brand-specific safety information. Our surveillance system has particular utility in monitoring the safety of influenza vaccines, given that they may vary in composition annually.     

Longitudinal,population-based cohort study of prenatal influenza vaccination and influenza infection in childhood

BackgroundInfluenza vaccination is recommended to protect mothers and their infants from influenza infection. Few studies have evaluated the health impacts of in utero exposure to influenza vaccine among children more than six months of age.MethodsWe used probabilistically linked administrative health records to establish a mother–child cohort to evaluate the risk of influenza and acute respiratory infections associated with maternal influenza vaccination. Outcomes were laboratory-confirmed influenza (LCI) and hospitalization for influenza or acute respiratory infection (ARI). Adjusted hazard ratios (aHRs) accounted for child’s Aboriginal status and were weighted by the inverse-probability of treatment.Results14,396 (11.5%) children were born to vaccinated mothers. Maternally vaccinated infants aged < 6 months had lower risk of LCI (aHR: 0.33; 95% CI: 0.13, 0.85), influenza-associated hospitalization (aHR: 0.39; 95% CI: 0.16, 0.94) and ARI-associated hospitalization (aHR: 0.85; 95% CI: 0.77, 0.94) compared to maternally unvaccinated infants. With the exception of an increased risk of LCI among children aged 6 months to < 2 years old following first trimester vaccination (aHR: 2.28; 95% CI: 1.41, 3.69), there were no other differences in the risk of LCI, influenza-associated hospitalization or ARI-associated hospitalization among children aged > 6 months.ConclusionStudy results show that maternal influenza vaccination is effective in preventing influenza in the first six months and had no impact on respiratory infections after two years of age.