Vaccines for pertussis and influenza: recommendations for use in pregnancy

The active immunization of pregnant women during pregnancy to protect them from disease and protect their neonate with passive antibodies is a biologic fact. Fortunately, many infectious diseases occur infrequently due to excellent pediatric vaccine programs. However, most adults and many physicians are unaware of the risks of not administering vaccines especially to pregnant women. Influenza vaccine (trivalent inactivated influenza vaccine) is recommended by (Advisory Committee on Immunization Practices (ACIP) for pregnant women in any trimester of pregnancy and Tetanus, reduced diphtheria, and pertussis (TdaP) vaccine is recommended by the ACIP to be given before pregnancy, during pregnancy, or in the immediate postpartum period. Only 2% of the adult US population is protected against pertussis and it is estimated that only 25% of pregnant women receive influenza vaccine during the influenza season. This chapter discusses trivalent inactivated influenza vaccine and TdaP use during pregnancy, the diseases they prevent, and the benefit to the neonate.     

Knowledge and attitude of pregnant women toward flu vaccination: a cross-sectional survey

Objective: The study was conducted to explore the knowledge of pregnant women about influenza, influenza vaccine during pregnancy and the attitudes regarding immunization.

Methods: A questionnaire based on the model proposed by Yudin in 2009 was translated, adapted and administered to 309 pregnant women in the third trimester of pregnancy between October 1 and December 1, 2013 at San Giovanni Calibita Fatebenefratelli hospital of Rome (Italy).

Results: Most of the interviewed women (68.9%) answered that influenza is highly contagious, 34.6% of them believed that pregnant women have the same risk of complications as non-pregnant women. Only 5.8% were aware that the vaccine is recommended for women in the second and third trimester of pregnancy and only 14.2% of women answered that the vaccine is safe during pregnancy. Only 3/309 women reported recommendation and offer of vaccination during current pregnancy, but none of them was vaccinated.

Conclusions: Overall, knowledge regarding influenza, implications during pregnancy and influenza vaccine was poor among pregnant women. In Italy, the National Vaccine Prevention Plan 2012–2014 recommends influenza vaccine during pregnancy, but only 18/309 were aware of this recommendation. These results suggest that in order to increase influenza vaccine acceptance it is necessary to improve pregnant women knowledge about influenza and to offer education to healthcare providers.     

Acceptability of maternal immunization against influenza: the critical role of obstetricians

Introduction: Pregnant women and infants are at increased risk of vaccine-preventable complications due to influenza. In Switzerland, immunization was first recommended to all pregnant women in 2009. We assessed the acceptability of this recommendation and its determinants two seasons later. Methods: Women having delivered in the University Hospitals of Geneva during March 2011 were asked to fill in a questionnaire assessing their knowledge, beliefs and acceptability of influenza vaccination during pregnancy. Results: The questionnaire was completed by 261/323 (80%) women. Out of 261, 213 (82%) were aware of increased risks of influenza during pregnancy, and 119/261 (46%) knew that immunization was recommended during pregnancy. Only 110/261 (42%) recalled an immunization advise during their pregnancy and only 47/261 (18%) had been immunized. A direct recommendation was the main predictor of immunization, associated with a 107-fold increased likelihood of vaccination. Factors identified by multivariate analyses as independently associated with the likelihood of immunization were to have been recommended immunization by a private (OR 9.1) or hospital (OR 4.7) obstetrician rather than a midwife, to have no fear that immunization could cause preterm delivery (OR 0.3) and to have been immunized in previous years (OR 10.7). Conclusion: Two years after the recommendation of influenza immunization during pregnancy, most post-partum women recalled being neither recommended nor adequately informed about influenza vaccine and its safety. This identifies major gaps in awareness and/or communication in healthcare workers and suggests that improving immunization safety/efficacy awareness among obstetricians as the most likely method to improve flu immunization during pregnancy.     

Influenza and tetanus, diphtheria, and acellular pertussis vaccinations during pregnancy

Vaccinations in pregnancy are an important aspect of prenatal care and of improving not only maternal health but also neonatal outcomes. Only 2 vaccines are specifically recommended during pregnancy: influenza and tetanus, diphtheria, and acellular pertussis (Tdap). Because influenza illness disproportionately affects pregnant women compared with other populations, annual prevention of influenza illness is recommended for all women who will be pregnant during influenza season (October to May). Influenza vaccination has been recently reported to also result in decreased febrile respiratory illnesses in the newborn, likely through passive antibody transfer. Pertussis infection rates are rising in the United States as vaccine-induced immunity wanes, with the mortality burden primarily seen in infants aged <6 months. Pertussis immunization with Tdap is now recommended for all pregnant women during the late second (>20 weeks) or third trimester with the intent to both protect the pregnant woman and provide passive antibody to the infant before vaccination at 2 months of age. Provider support for these recommendations regarding both annual influenza vaccination and postpartum Tdap vaccination during pregnancy is critical to ensuring vaccine delivery and improving both maternal and fetal health. The article reviews the epidemiology and clinical aspects of influenza and pertussis infection with particular attention to pregnancy and recommendations for vaccination in these women. TARGET AUDIENCE: Obstetricians and gynecologists, ophthalmologists, neurologists, family physicians, emergency room physicians LEARNING OBJECTIVES: After completing this CME activity, obstetricians and gynecologists should be better able to analyze how influenza infection disproportionally affects pregnant women. Assess how influenza vaccination improves maternal and likely neonatal outcomes. Evaluate pertussis infection and immunity in adults, and counsel pregnant women as to the benefits of Tdap vaccination, particularly for the infant.     

Pregnant Women’s Knowledge of Influenza and the Use and Safety of the Influenza Vaccine During Pregnancy

IntroductionWe wished to assess pregnant women’s knowledge of influenza, vaccine safety during pregnancy and breast feeding, and the recommendations for use of the influenza vaccine in pregnancy.MethodsWe performed a cross-sectional survey of postpartum women during influenza season in 2006.ResultsPregnant women’s overall knowledge of these subjects was poor. Most women (95%) knew that influenza is highly contagious, but almost 90% incorrectly believed that pregnant women have the same risk of complications as non-pregnant women. Only one half of the women were aware of national recommendations for vaccination during pregnancy and that the vaccine is safe during pregnancy and breast feeding, and 80% incorrectly believed that the vaccine can cause birth defects. Only 20% of women had been offered the vaccine during the current pregnancy or a prior pregnancy.ConclusionsPregnant women’s knowledge about influenza vaccine recommendations and safety during pregnancy is poor. There is substantial room for improvement among prenatal care providers in both patient education and offering the vaccine.     

Hospitalizations with respiratory illness among pregnant women during influenza season

OBJECTIVE: To examine hospitalizations with respiratory illness among pregnant women in the United States during periods of influenza activity. METHODS: Data were obtained from the Healthcare Cost and Utilization Project National Inpatient Sample (NIS), the largest publicly available all-payer hospital discharge database. Hospitalizations for respiratory illness and pregnancy were classified with International Classification of Diseases, 9th Revision, Clinical Modification codes. Analyses were stratified by delivery status. Discharge characteristics, length of stay, and complications of delivery among hospitalized pregnant women with and those without respiratory illness were compared. RESULTS: During the 1998-2002 influenza seasons, 3.4 per 1,000 hospitalizations of pregnant women included diagnoses of respiratory illness. Characteristics of pregnancy hospitalizations associated with higher odds of respiratory illness were presence of a high-risk condition for which influenza vaccination is recommended (adjusted odds ratio [OR] 3.2, 95% confidence interval [CI] 3.0-3.5 and OR 6.0, 95% CI 5.2-6.9 for nondelivery and delivery, respectively), Medicaid/Medicare as primary expected payer of care (OR 1.2, 95% CI 1.1-1.3 and OR 1.9, 95% CI 1.7-2.2 for nondelivery and delivery, respectively), and hospitalization in a rural area (OR 1.2, 95% CI 1.1-1.4 for nondelivery). During influenza season, hospitalized pregnant women with respiratory illness had significantly longer lengths of stay and higher odds of delivery complications than hospitalized pregnant women without respiratory illness. CONCLUSION: Hospitalizations with respiratory illness among pregnant women during influenza season are associated with increased burden for patients and the health care system. Intervention efforts to decrease influenza-related respiratory morbidity among pregnant women should be encouraged. LEVEL OF EVIDENCE: III.     

Influenza-Attributed Hospitalization Rates Among Pregnant Women in Canada 1994–2000

BackgroundAlthough it is recommended that pregnant women at risk for influenza complications receive influenza vaccine, it is not clear if healthy pregnant women are at increased risk for adverse outcomes. We aimed to estimate the rate of hospitalization attributable to influenza for healthy pregnant women and for those with known co-morbidities.MethodsHospital admission records of women admitted from 1994 to 2000 with a respiratory condition during pregnancy were extracted from the hospitalization database (Canadian Institute of Health Information). Admissions for childbirth were excluded. Weekly admissions, stratified by the presence of co-morbid conditions, were modelled as a function of viral activity, seasonality, trend, and holiday effects using Poisson regression with proxies for influenza and other viral activity developed previously for similar age-specific models of influenza-attributed hospital admissions.ResultsApproximately 300 hospitalizations of pregnant women per year were attributed to influenza, of which 140 were in women with co-morbidities. This hospitalization rate corresponds to 150 (95% CI 140–170) hospitalizations per 100 000 pregnant women per year. An estimated 1 in 1000 healthy pregnant women were hospitalized due to influenza per year. Asthma was the most important risk factor, accounting for an estimated 450 (95% CI 300–600) admissions per 100 000 pregnant women. Admission rates in pregnant women were relatively constant across multiple influenza seasons of varying severity among older adults. During the four weeks of peak influenza activity, 60% of respiratory-related admissions of otherwise healthy pregnant women could be attributed to influenza.ConclusionHealthy pregnant Canadian women have consistently higher rates of hospital admission attributable to influenza infection than their non-pregnant peers. The admission rate for healthy pregnant women corresponds to the rate for men and women aged 65 to 69 years, which suggests that this population may benefit from annual influenza immunization.     

What the obstetrician/gynecologist should know about thyroid disorders

Thyroid disease is a common disorder faced by women of all ages. Because of its high incidence in women, recognizing and treating thyroid dysfunction often becomes the responsibility of the obstetrician/gynecologist. It is important that women's healthcare providers understand how the thyroid's function changes as a woman enters her reproductive years, as well as during pregnancy and menopause. Current guidelines for diagnosing and managing thyroid dysfunction and recommended treatment strategies are discussed in this review. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this educational activity, the obstetrician/gynecologist should be better able to evaluate normal thyroid physiology and pathophysiology of thyroid dysfunction; assess appropriate screening options for their patients; and diagnose and manage thyroid disorders common among reproductive-aged women.     

Pregnancy and autoimmune diseases

Autoimmune diseases (AID) are more prevalent in women than in men, and pregnancy-related factors such as hormonal modulation and fetal microchimerism may influence the future risk of maternal AID. For women with AID, optimizing reproductive health requires a continuum of multidisciplinary care that initiates well before the desire for pregnancy is articulated. Family planning is essential so that pregnancy can be timed when disease is stable and to allow for appropriate medication adjustments. When contraception is used, the choice of method needs to take into consideration underlying disease and laboratory features. For females undergoing gonadotoxic therapy, options for preserving ovarian health and fertility warrant consideration, even among those who are not contemplating future pregnancy. Both maternal and fetal outcomes are optimized with multispecialty care as well as close monitoring during pregnancy and the postpartum period and when treatment regimens compatible with pregnancy are maintained to control underlying disease activity.     

Influenza Vaccine Programs and Pregnancy: New Canadian Evidence for Immunization

Among healthy pregnant women, excess deaths due to influenza were documented during pandemics, but the impact of influenza on pregnant women in non-pandemic years is not clear. In Canada, influenza immunization is recommended for pregnant women only if they have comorbidities known to place them at increased risk of complications or if they deliver during influenza season, therefore becoming a contact of a high-risk infant. The National Advisory Committee on Immunization has indicated that additional evidence, relevant to healthy pregnant Canadian women, is needed to support a recommendation for influenza immunization for all pregnant women. In this commentary we summarize new Canadian data supporting universal influenza immunization for pregnant women and discuss ways in which the Society of Obstetricians and Gynaecologists of Canada might take a leadership role in making influenza vaccination in pregnancy a priority to decrease influenza morbidity in pregnant Canadian women.     

Reiseschutzimpfungen für Schwangere und Frauen mit Kinderwunsch

Infectious diseases are a potential source of maternal and fetal morbidity and mortality. Prior to international travels, pregnant women and women actively attempting to become pregnant should seek specific counselling regarding necessary travel immunizations. This is especially important if their travel destination is a country with areas endemic for malaria, yellow fever, tuberculosis, hepatitis, human immunodeficiency virus-associated diseases, leishmaniosis, toxoplasmosis, filariosis, Japanese encephalitis, rubella, typhus, leptospirosis, Dengue fever, Helicobacter pylori gastritis, and trypanosomiasis. Toxoid vaccinations, inactivated vaccinations, and immunoglobulins may be administered during pregnancy, whereas live vaccinations are contraindicated. Recommended vaccinations during pregnancy are tetanus, diphtheria, and pertussis in case of an insufficient immunization status, as well as the seasonal influenza vaccination. Specific travel vaccinations include all standard vaccinations. In addition, hepatitis A, yellow fever, and polio in certain countries with endemic areas according to World Health Organization (WHO) specifications are recommended. Some countries may have additional vaccination regulations regarding cholera and meningococcus. Vaccinations “per indication” are required if the travel destination is an area with specific locally increased risks for typhoid, rabies, tick-borne encephalitis, influenza A/H5N1, Japanese encephalitis, cholera, or yellow fever. There is no effective vaccination against the zika virus. Thus, pregnant women and women actively attempting to become pregnant should refrain from travelling to countries endemic for zika virus.     

Gewichtszunahme Schwangerer und postpartale Gewichtsretention

Overweight and particularly obese women (BMI????30?kg/m²) are at risk for complications in pregnancy. One third of overweight and more than 50% of obese pregnant women gain more weight than generally recommended. Both increased prepregnancy BMI and excessive weight gain during pregnancy are crucial predictors of perinatal outcome (e.g. higher risk for childhood obesity and cardiovascular diseases). Apart from preconceptional weight loss, detailed information and determination of individual weight gain goals (IOM guidelines) as well as diet and exercise recommendations are of particular importance for obstetric care professionals. Overweight and obese women should be encouraged to breastfeed. Detailed advice should be offered regarding postpartum weight retention, lifestyle interventions and physical activity.     

Influenzainfektion in der Gravidit?t

For pregnant women influenza (seasonal and pandemic) may have a more severe clinical course, increased complication rate, and higher case fatality rate. Pregnant women are at younger age when hospitalized. There is an increased risk for adverse outcomes among infants born to mothers infected with influenza during pregnancy. Pregnant women should be considered a high priority for receipt of influenza vaccine with the aim of preventing both the illness and mortality in mother and infant.     

The Association Between Influenza Vaccine in Pregnancy and Adverse Neonatal Outcomes

ObjectiveTo determine whether neonatal outcomes differ between women vaccinated during pregnancy and those not vaccinated.MethodsSelf-reported history of receipt of influenza vaccination during pregnancy was collected from women at the time of admission for obstetrical delivery at the IWK Health Centre in Halifax, Nova Scotia, beginning in April 2006. The cohort for this study included women who delivered a singleton infant prior to November 2009, reflecting the pre-pandemic H1N1 vaccination period. Neonatal outcomes were compared using logistic regression between vaccinated and non-vaccinated women.ResultsOverall, 1957 of 9781 women (20%) included in the cohort received influenza vaccine during their pregnancy. The adjusted odds ratio and 95% confidence interval for a small for gestational age infant (lowest 10th percentile birth weight for gestational age and sex) was 0.80 (95% CI 0.65 to 0.95) for vaccinated women relative to non-vaccinated women. The adjusted odds ratio for a low birth weight infant was 0.74 (95% CI 0.58 to 0.95). Rates of preterm birth and a composite indicator of adverse neonatal outcomes were lower among vaccinated women, but were not statistically significant. The effects of maternal vaccination on neonatal outcomes did not differ between high- and low-risk women.ConclusionAs evidence continues to mount in support of improved neonatal outcomes associated with receiving influenza vaccination during pregnancy, enhanced public health measures are necessary to encourage pregnant women to receive the influenza vaccine.     

Maternal morbidity and perinatal outcomes among pregnant women with respiratory hospitalizations during influenza season

OBJECTIVES: A population-based assessment of maternal and perinatal morbidity related to respiratory illness during influenza season among pregnant women has not been published. The objectives of this investigation were to describe and quantify the impact of respiratory hospitalization during pregnancy on serious maternal and perinatal morbidity. STUDY DESIGN: A matched cohort study using an administrative database of pregnant women enrolled in the Tennessee Medicaid population to determine pregnancy outcomes associated with respiratory hospitalizations during influenza season. Pregnant women aged 15 to 44 years with a respiratory hospitalization during influenza seasons 1985-1993 were matched by gestational age and presence of comorbidity with pregnant control subjects without a respiratory hospitalization. RESULTS: During the eight influenza seasons studied, 293 women with singleton pregnancies had respiratory disease hospitalizations (5.1:1000). Women with asthma had high rates of such hospitalization (59.7:1000). Compared with matched controls, women with respiratory hospitalizations had similar modes of delivery, delivery length of stay, and episodes of preterm labor. The prevalence of prematurity and low birth weight among infants born to such women was likewise similar between the two groups. CONCLUSION: In this population of pregnant women, those with asthma accounted for half of all respiratory-related hospitalizations during influenza seasons, with 6% of pregnant women with asthma requiring respiratory hospitalization during influenza season, (odds ratio 10.63, 95% CI, 8.18-13.83, compared with women without a medical comorbidity). We detected no significant increase in adverse perinatal outcomes associated with respiratory hospitalizations during influenza season.     

Influenza vaccination during pregnancy. Patients' and physicians' attitudes.

OBJECTIVE: To identify potentially remediable attitudinal factors among women and their physicians that may present barriers to influenza vaccination during pregnancy. STUDY DESIGN: We conducted a prospective survey study administered concurrently during influenza season (January-March 2000) to postpartum women in an urban, high-volume medical center and to practicing obstetricians in the metropolitan Los Angeles area. Analyses focused on individual questions' relation to the outcomes of: (1) patients' receipt of influenza vaccine during the recently completed pregnancy, and (2) physicians' discussion of influenza vaccine with their pregnant patients. RESULTS: Surveys were completed by 242 postpartum women and 113 physicians. Among the women, 22% had discussed influenza vaccine with their physicians during pregnancy, with only 8% of respondents having been vaccinated. Significantly more physicians stated that they discussed vaccination with their patients than did women (74% vs. 22%; P < .001). Physicians were more likely to recommend vaccine if they were aware of current Centers for Disease Prevention and Control guidelines (RR = 2.6, 1.1-5.9), gave vaccinations in their offices (RR = 1.2, 1.01-1.4) and had been vaccinated against influenza themselves (RR = 1.9, 1.3-2.8). CONCLUSION: Influenza vaccination during pregnancy occurred infrequently in this study cohort, and a significant discrepancy was seen between patients' and physicians' impressions of whether its use or recommendation had been discussed. Gaps existed in both groups' understanding of potential benefits of influenza vaccine for both pregnant women and their newborns. The survey results suggest potential strategies for targeting improved educational programs for physicians and patients to improve influenza vaccination rates for pregnant women.     

Influenza vaccination during pregnancy and factors for lacking compliance with current CDC guidelines

Background.?The Center for Disease Control and Prevention (CDC) and the American College of Obstetricians and Gynecologists (ACOG) recommend influenza vaccination for all pregnant women during the influenza season. However, the actual rate of vaccination is substantially below the target levels. Given the recent emergence of novel influenza strains, there is an important need to address knowledge gaps in women and their healthcare providers to improve vaccination coverage for pregnant women during inter-pandemic and pandemic periods. This study attempted to identify potentially remediable attitudinal factors among women and their physicians that may present barriers to influenza vaccination and then assess the impact of interventions to increase the influenza vaccination rate in pregnant women.

Methods.?This prospective study initially analyzed patient and physician knowledge regarding the influenza vaccine in pregnancy and then examined the impact of several interventions aimed to increase immunization rates implemented over the following year. Influenza vaccination rates were assessed before and after the interventions.

Results.?Five hundred twenty patients were enrolled in the study during the influenza season 2007/2008. Only 19% of those patients reported receiving the influenza vaccination and only 28% recalled that the vaccine was offered. Following this, in the summer and fall of 2008, we performed a physician education program and distributed posters advertising the influenza vaccine to all offices offering prenatal care in our area in order to increase patient awareness of the need for the vaccine. In the following influenza season, we again reassessed the vaccination rate and patient's knowledge and awareness of the vaccine in 480 postpartum women. Influenza vaccination rates increased from 19% to 31%. After the intervention, 51% of patients recalled that the vaccine was offered to them during the pregnancy as opposed to only 28% the year prior.

Conclusion.?Understanding the specific barriers to vaccination that our population faced was helpful in designing the interventions to improve knowledge and acceptance of influenza vaccination in pregnancy, which led to an increased vaccination rates in women.     

Vaccines in pregnant women and research initiatives

Successful maternal immunization requires consideration of maternal and infant disease burden, biological factors affecting immune response and placental transport of antibodies, optimal timing of immunization, safety and acceptability. Tetanus, inactivated influenza and acellular pertussis vaccines are recommended during pregnancy; others are recommended when maternal risk of infection is high. The development of new conjugate vaccines for use in adults may reduce global maternal and infant disease burden. Maternal immunization against group B streptococcus is projected to be superior to current preventative strategies in decreasing disease. Further evaluation of maternal immunization strategies to prevent maternal and infant infections is needed.