Why, when and for what diseases pregnant and new mothers "should" be vaccinated

Maternal vaccination: A narrative review

Background

Vaccinations in general are considered to be one of the greatest achievements in medicine, saving millions of lives globally.

Aim

This narrative review highlights issues related to vaccination in pregnancy and provides information on those vaccines registered for use in pregnancy.

Method

Published articles on vaccinations in pregnancy are included in this review. The search engines used included PubMed, Medline, Google Scholar, and ScienceDirect.

Results

Vaccinations during pregnancy are more likely to be administered in high income countries (HICs) compared to low-income countries (LICs) due to easier access to healthcare services and better communicable disease awareness. Maternal and perinatal morbidity and mortality rates associated with infectious diseases are higher in LICs with access to maternal care services, infrastructure and hospital equipment lacking in these settings.

Conclusion

Suitable vaccinations are recommended for use in pregnancy to prevent harm to women, their foetuses and newborns from some communicable diseases, and they have resulted in declines in maternal and infant morbidity and mortality. Furthermore, this review has shown that vaccination during pregnancy is not only safe for both the woman and her foetus but also effective. Therefore, health professionals and national governments should strongly consider approved vaccinations prior to or during pregnancy.

Contribution

This review provides insight on the necessity of vaccination during pregnancy. In addition, it urges health professionals to inform patients of the importance of regular antenatal visits, and to receive the required vaccinations for a better health outcome.

Understanding drivers of vaccine hesitancy among pregnant women in Nigeria: A longitudinal study

Vaccine-preventable-diseases are major contributors to disease burden in Sub-Saharan Africa. There is dearth of knowledge on the drivers of childhood vaccine hesitancy in Nigeria and its impact on coverage. Although understudied, pregnant women are a particularly important vulnerable group and very relevant for childhood vaccination decisions. This study’s aims are to adapt Confidence, Complacency, Constraints, Calculation, and Collective Responsibility, also known as the 5C psychological antecedence scale for the Nigerian context and to measure predictors of intention to vaccinate among pregnant women (prenatal) and subsequent vaccination behavior (postnatal). It is a longitudinal study that used multi-stage sampling procedure. One healthcare facility was selected from each district in five regional clusters, from which 255 pregnant women were randomly drawn. A standardized questionnaire was used to collect relevant data, including the 5C and some additional variables. Multiple linear regression using backward elimination analysis was performed to identify intention at prenatal and behavior at postnatal. Pregnant women’s intention to vaccinate unborn children was lower if they were Muslims, had lower confidence in public health system, if husband approval was important, and if they believed in rumor. At postnatal, vaccination behavior was more likely to follow mothers’ religious beliefs, when confidence in vaccine effectiveness was high and when mothers felt responsible for the collective. However, everyday stress (constraints) related to less vaccination behavior, and intention did not predict actual vaccination behavior. The 5C scale needs revision before being widely used in Nigeria. Yet, it is a better tool for measuring vaccination behavior than intention.

Reliability of information available on popular websites about vaccination of pregnant women

OBJECTIVE

To analyze the reliability of information available on popular websites about vaccination of pregnant women according to the recommendations of the Brazilian Ministry of Health.

METHOD

Descriptive and comparative study. For data collection, a checklist composed of information on recommended, contraindicated, and indicated vaccines in special situations during pregnancy, according to the Ministry of Health, was elaborated.

RESULTS

None of the analyzed websites presented all the recommended information. Contraindications, most common adverse events, simultaneous administration of vaccines, information on the DT vaccine, and recommended vaccines in special situations were presented by a minority of websites.

CONCLUSION

Information available on websites about the vaccination of pregnant women is not always based on the recommendations and misinformation may interfere with the acceptance of this practice. The importance of the professionals of the multidisciplinary team as information mediators, particularly the nurse, is emphasized, as is the need for regulating the production and dissemination of information on the internet.

A retrospective analysis of incident pregnancy in phase 1 and 2a HIV-1 vaccine study participants does not support concern for adverse pregnancy or birth outcomes

Background

Pregnancies occur during HIV-1 vaccine clinical trials, despite requirements for women of reproductive potential to use effective contraception. Deployment of an effective HIV-1 vaccine regimen will likely target adolescents and young adults and therefore safety for pregnant and breastfeeding women will need to be addressed.

Methods

We performed a retrospective, cross-protocol analysis to identify and compare pregnancy outcomes reported in 53 Phase 1 and Phase 2a HIV-1 vaccine clinical trials conducted by the HIV Vaccine Trials Network (HVTN).

Results

Two thousand six hundred seventy-three women of reproductive potential were identified and 193 pregnancies were reported. 39 of 53 (74%) studies had at least one pregnancy reported with an overall pregnancy rate of 3.15 per 100 woman-years (w-yr). While active contraception use was required during study participation, 13 of the 53 studies also contained a long-term follow up period during which pregnancy was no longer discouraged. The pregnancy rate during main study participation was 3.09 per 100 w-yr, while pregnancies occurred at a slightly greater rate in the long-term follow up period (3.22 per 100 w-yr). Adverse pregnancy outcomes were reported at similar rates between vaccinees and placebo recipients when vaccine vectors, adjuvant used, or geographic region were examined.

Conclusion

Although there is considerable heterogeneity amongst the different vaccine trials, there appears to be no obvious indication of increased risk of adverse pregnancy or birth outcomes in these early phase HIV-1 vaccine studies. More complete data on pregnancy outcomes should be collected in early phase HIV-1 vaccine clinical trials to better inform subsequent efficacy trials.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06431-x.

Adverse events following immunization in pregnant women from Minas Gerais

OBJECTIVE:

To analyze the distribution of adverse events following immunization (AEFI) in pregnant women in the state of Minas Gerais, between 2015 and 2019.

METHODS:

This is an epidemiological, descriptive study conducted with AEFI data from 2015 to 2019, recorded in the Adverse Events Surveillance Information System, in the state of Minas Gerais (MG), Brazil. A total of 670 AEFI were analyzed in pregnant women. The estimates were presented in proportions, according to the year of occurrence, health macro-region of Minas Gerais and immunobiological administered.

RESULTS:

The year in which there were the most records was 2017 (36.8%). Among the 14 macro-regions, the ones with the lowest and highest number of records were the Vale do Jequitinhonha (0.5%) and Center (31.8%), respectively. The vaccines contraindicated during pregnancy represented 27.6% of the total notifications. The total of 69.5% of the cases were considered immunization errors. In 75.9% of the records, the variable of medical care was ignored, and in 73.7% of the cases no information on the evolution was presented.

CONCLUSION:

This study shows the need for continuing education for the multidisciplinary team, in order to reduce cases of AEFI and ensure the adequate completion of notifications by health professionals.

Vector-borne diseases in pregnancy

Vector-borne infections cause a significant proportion of world-wide morbidity and mortality and many are increasing in incidence. This is due to a combination of factors, primarily environmental change, encroachment of human habitats from urban to peri-urban areas and rural to previously uninhabited areas, persistence of poverty, malnutrition and resource limitation in geographical areas where these diseases are endemic. Pregnant women represent the single largest ‘at risk’ group, due to immune-modulation and a unique physiological state. Many of these diseases have not benefitted from the same level of drug development as other infectious and medical domains, a factor attributing to the ‘neglected tropical disease’ title many vector-borne diseases hold. Pregnancy compounds this issue as data for safety and efficacy for many drugs is practically non-existent, precluding exposure in pregnancy to many first-line therapeutic agents for ‘fear of the unknown’ or overstated adverse pregnancy-foetal outcomes. In this review, major vector-borne diseases, their impact on pregnancy outcomes, current treatment, vaccination and short-comings of current medical practice for pregnant women will be discussed.

Flu Vaccination Attitudes, Behaviours, and Knowledge among Health Workers

The aim of this work is to evaluate the attitudes, behaviours, and knowledge of health workers employed at an Italian University Hospital on the topic of vaccinations and in regard to flu vaccination. To this end, the study provided for the articulation of a computerised questionnaire on the digital platform EUSurvey which was administered online via e-mail to a sample of 457 health workers, in the period between November 2018 and March 2019. The data were subjected to descriptive and inferential statistical analysis. In particular, a logistic regression analysis was carried out in order to evaluate the relationship between the variables collected and the dichotomous outcome (vaccinated/unvaccinated subjects in the 2018–2019 season). The results, in line with what has been reported by the literature, highlighted that vaccine hesitancy is prevalent also among health workers. Furthermore, according to our study, only 30.6% of the health care workers had the flu vaccination. The survey points out the need to plan educational and informative interventions aimed at changing the attitudes, behaviours, and knowledge of health workers in the field of flu vaccination, for the purpose of protecting the health of healthcare personnel and their patients.

An Overview of Tickborne Infections in Pregnancy and Outcomes in the Newborn: The Need for Prospective Studies

Tick-borne infections are an ever-increasing issue internationally, many factors contribute to this including a changing climate. Pregnant women represent the single largest vulnerable group in populations due to a relative immune deficiency status. Infections in pregnant women have the added gravity of potential infection in the developing fetus which may have catastrophic consequences including death in-utero or lifelong debilitation. Currently there is a paucity of data surrounding tick-borne infections in pregnancy and long-term outcomes for mother and infant for conditions like Lyme disease and co-infections. At present there are no established international surveillance systems to identify and gain understanding of these infections in pregnancy. Furthermore, the removal of Congenital Lyme Disease from ICD-11 codes hampers dialogue and characterization of borreliosis in pregnancy and stifles future developments of this understudied domain. This review makes the case for further study and re-opening a dialogue of tick-borne infections in pregnancy.

Exacerbations of autoimmune diseases during pregnancy and postpartum

Autoimmune diseases represent a complex heterogeneous group of disorders that occur as a results of immune homeostasis dysregulation and loss of self-tolerance. Interestingly, more than 80% of the cases are found among women at reproductive age. Normal pregnancy is associated with remarkable changes in the immune and endocrine signaling required to tolerate and support the development and survival of the placenta and the semi-allogenic fetus in the hostile maternal immune system environment. Gravidity and postpartum represent an extremely challenge period, and likewise the general population, women suffering from autoimmune disorders attempt pregnancy. Effective preconception counseling and subsequent gestation and postpartum follow-up are crucial for improving mother and child outcomes. This comprehensive review provides information about the different pathways modulating autoimmune diseases activity and severity, such as the influence hormones, microbiome, infections, vaccines, among others, as well as updated recommendations were needed, in order to offer those women better medical care and life quality.

Trends in Hospital Admissions for Pertussis Infection: A Nationwide Retrospective Observational Study in Italy, 2002-2016

Background: Pertussis is a highly contagious infectious disease which continues to be an important public-health issue despite the high immunization coverage rates achieved. However, evidence of increased circulation of pertussis among adolescents and adults due to waning immunity and atypical clinical manifestations seem to be the main reasons for its resurgence. The aim of this study was the analysis of the epidemiological trend for pertussis-related hospitalizations in Italy, in relation with vaccination coverage and information from laboratory confirmed cases of pertussis. Methods: A retrospective observational study investigating hospitalizations for pertussis from 2002 to 2016 in Italy was conducted. Frequencies and rates of hospitalization were analyzed and hospitalization data were compared with a series of already published laboratory confirmed data. Results: This study highlighted a rising trend for pertussis hospitalizations in Italy since 2008. Infants aged <1 year showed the highest frequencies (63.39%) and average rates (74.60 × 100000 infants) of hospitalization despite an extremely high vaccination coverage (95.89%). An increasing trend of hospitalization frequency emerged for the age group with levels of IgG antibodies to pertussis toxin compatible with pertussis infection within the last year (20–29 years old age group). Conclusions: The rising trend for pertussis hospitalizations and the greater involvement of infants aged <1 year require an integrated approach, including the implementation of booster doses administration in adolescence and adulthood, the vaccination of pregnant women and the cocoon strategy.

Impact of Pertussis on the Italian population: Analysis of hospital discharge records in the period 2001-2014

OBJECTIVES

The study aimed to analyze and update the impact of pertussis on the Italian population by evaluating pertussis-related hospital admissions in the period 2001-2014.

DESIGN OR METHODS

Hospital Discharge Records (HDR) were provided by the National Archive of HDR data of the Ministry of Health. Only hospitalizations included in the primary diagnosis were evaluated. Significant trends over the considered years were assessed as average annual percent changes (AAPC) applying the Joinpoint model.

RESULTS

A total of 7,102 hospital admissions for pertussis (main diagnosis) were registered; the trend of hospitalizations progressively decreased from >1/100,000 inhabitants in the years 2001-2004 to 0.64/100,000 inhabitants in 2014. A great part of hospitalizations (63.6%) involved subjects <1 year of life; almost 20% of cases were registered in the age class 5-14 years. The Joinpoint analysis showed a statistically significant variation in some age classes.

CONCLUSIONS

Even if this study shows a decreasing trend in the number of pertussis-related hospitalizations, the impact of the disease in Italy in terms of hospital admissions continues to be relevant, especially in the <1 year age class. Pertussis therefore continues to be, in Italy as well as in other European countries, an important public health issue.

Insights and expectations for Tdap vaccination of pregnant women in Italy

BACKGROUND

Pertussis is a widespread vaccine-preventable disease, associated with an increasing trend to hospitalization among newborns. Pertussis in newborns can be fatal, and the most effective way to prevent it is maternal immunization (MI) with a reduced antigen content tetanus, diphtheria, and acellular pertussis vaccine (Tdap). In Italy, the National Immunization Plan (NIP) 2017-2019 introduced de novo Tdap vaccination during each pregnancy at no cost for the recipient. Despite this, vaccination coverage is suboptimal. This survey of pregnant women across Italy was conducted to investigate their knowledge and expectations of Tdap.

METHODS

A cross-sectional survey was conducted. Pregnant women up to 28th gestational weeks were interviewed by Telephone using a questionnaire with 16 questions. Statistics were descriptive.

RESULTS

The final sample recruited 600 respondents evenly distributed across Italy. The average duration of pregnancy at the time of the interview was 20.8 weeks (standard deviation [SD] 6.0). Most women (60.7%) were between 30 and 40 years of age. About half were aware of the risks of pertussis for newborns (54.5%) and the increased risk of hospitalization (59.8%); 47.2% were aware that Tdap MI was offered free of charge under the NIP. Safety information regarding the mother and newborn was considered the most important information in deciding whether to be vaccinated (47.4%), followed by safety information related only to the newborn (29.5%). About half (52.2%) stated that they would "certainly" accept MI, and 25.3% would like to receive more information. Gynecologists were the preferred healthcare providers (HCPs) for the provision of MI information (34.3%), followed by pediatricians (25.5%). Two-thirds of the respondents would prefer to be informed about MI before getting pregnant (66.0%). Vaccines investigated specifically for use in pregnancy were preferred by respondents. Overall, no relevant differences were observed between women pregnant for the first time and those with more than one pregnancy, nor between geographical regions.

CONCLUSIONS

The results show room for improving the awareness and understanding of the risks of pertussis for infants and the protective role of MI. The pregnant women preferred to receive advice on MI from an HCP, primarily their gynecologist. They were most interested in information on the safety profile of Tdap during pregnancy, on the mother, fetus, and newborn. The potential impact of this study to support clinical practice of Healthcare Providers is highlighted in the Focus on the Patient section. [Formula: see text].

Spatial analysis of vaccination against Hepatitis B in pregnant women in an urban Brazilian area

The objective of this article is to analyze the spatial distribution of Hepatitis B vaccine (HBVAC) of pregnant women. This is a cross-sectional study carried with 266 puerperae. The HBVAC record was obtained through the prenatal care booklet. The spatial scanning technique was used to detect a cluster of risk for the presence or absence of an HBVAC record. After this cluster identification, the individual and environmental variables were compared between the Coverage Areas of Basic Health Units (CAs-BHUs). The mean prevalence of non-HBVAC was 88.34%. Scan spatial scan analysis observed a cluster of a high prevalence of puerperae with a HBVAC record. Comparative analyses have shown that paid work and the number of prenatal visits are positively associated with an HBVAC record. Given the above, this work brings a reflection on possible disparities with other CAs-BHUs, besides the influence of the environmental perspective. It should be emphasized that the vaccination situation is influenced not only by factors intrinsic to the individuals. However, in this study, the results indicate that individual variables are predominantly mandatory in the decision of HBVAC uptake among pregnant women.