Maternal Vaccination and Vaccine Hesitancy

Paid Family Leave and Prevention of Acute Respiratory Infections in Young Infants

Importance

Acute respiratory tract infections are the leading cause of emergency department visits and hospitalizations in US children, with highest risks in the first 2 months after birth. Out-of-home childcare settings increase the spread of respiratory tract infections. The study team hypothesized that access to state-paid family leave could reduce acute care encounters (hospital admissions or emergency department visits) for respiratory tract infections in young infants by reducing out-of-home childcare transmissions.

Objective

To determine if the 2018 introduction of paid family leave in New York state reduced acute care encounters for respiratory tract infections in infants 8 weeks or younger.

Design, Setting, and Participants

This population-based study of acute care encounters took place in New York state and New England control states (Maine, Massachusetts, New Hampshire, Vermont) from October 2015 through February 2020. Participants included infants aged 8 weeks or younger. Controlled time series analysis using Poisson regression was used to estimate the impact of paid family leave on acute care encounters for respiratory tract infections, comparing observed counts during respiratory virus season (October through March) with those predicted in the absence of the policy. Acute care encounters for respiratory tract infections in 1-year-olds (who would not be expected to benefit as directly from the policy) were modeled as a placebo test.

Intervention

New York State Paid Family Leave policy, introduced on January 1, 2018, providing 8 weeks of paid leave for eligible parents.

Main Outcomes and Measures

Emergency department visits or hospitalizations with International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD) codes for upper or lower respiratory tract infections or associated symptoms (ie, fever, cough), excluding newborn hospitalizations. The secondary outcome was acute care encounters for respiratory syncytial virus (RSV) bronchiolitis.

Results

There were 52 943 acute care encounters for respiratory infection among infants 8 weeks or younger. There were 15 932 encounters that were hospitalizations (30%) and 33 304 of the encounters were paid for by Medicaid (63%). Encounters were 18% lower than predicted (relative percentage change = -17.9; 95% CI, -20.3 to -15.7) after the introduction of paid family leave. RSV encounters were 27.0% lower (95% CI, -30.9 to -23.5) than predicted. Similar reductions were not observed in 1-year-olds (relative percentage change = -1.5; 95% CI, -2.5 to -0.6).

Conclusions

New York state's paid family leave policy was associated with reduced acute care encounters for respiratory tract infections in young infants. These findings may be useful for informing implementation of paid family leave federally and in the states that have not enacted paid family leave policies.

Confronting the challenge: a regional perspective by the Latin American pediatric infectious diseases society (SLIPE) expert group on respiratory syncytial virus-tackling the burden of disease and implementing preventive solutions

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory infections in children around the world. The post-pandemic era has resulted in a notable increase in reported cases of RSV infections, co-circulation of other respiratory viruses, shifts in epidemiology, altered respiratory season timing, and increased healthcare demand. Low- and middle-income countries are responsible for the highest burden of RSV disease, contributing significantly to health expenses during respiratory seasons and RSV-associated mortality in children. Until recently, supportive measures were the only intervention to treat or prevent RSV-infection, since preventive strategies like palivizumab are limited for high-risk populations. Advances in new available strategies, such as long-acting monoclonal antibodies during the neonatal period and vaccination of pregnant women, are now a reality. As the Regional Expert Group of the Latin American Pediatric Infectious Diseases Society (SLIPE), we sought to evaluate the burden of RSV infection in Latin America and the Caribbean (LAC) region, analyze current strategies to prevent RSV infection in children, and provide recommendations for implementing new strategies for preventing RSV infection in children in LAC region.

Successful Elimination of Endemic Rubella in the WHO European Region. Is It Proper to Remove the Recommendation for Preconceptional Immunization?

BACKGROUND

Rubella is a contagious viral infection that has garnered significant attention in the field of public health due to its potential consequences, especially during pregnancy. In recent decades, it has been recommended that non-immune women receive immunization during the preconceptional and/or postpartum periods. The goal of this strategy is to prevent primary rubella infection in order to protect pregnant women against congenital rubella syndrome. In November 2022, the WHO's Regional Verification Commission declared the elimination of rubella infection in Italy. In recent years, the main migration flows to Italy have originated from regions where rubella has not yet been eliminated and where no program is in place to achieve this goal.

OBJECTIVE

The aim of this study was to retrospectively assess rubella immunity in pregnant women who have attended three delivery centers in Rome over the past three years, from January 2021 to May 2023.

METHODS

Data about the rubella serological status of 7937 non-consecutive pregnant women were collected. Univariate analysis was performed to verify any difference between the study groups in terms of age distribution.

RESULTS

Anti-rubella IgG antibodies were found in 7224 (91%) women while 713 (9%) were susceptible to rubella (IgG negative), without differences in terms of immunity rate between Italian and non-Italian women. Age analysis showed a statistically significant older age of immune women than receptive women and of Italian immune women than non-Italian immune women.

CONCLUSIONS

The National Plan for the Elimination of Measles and Congenital Rubella aimed to achieve a percentage of susceptible women of childbearing age below 5%. These data indicate the relevance of maintaining the recommendation for preconceptional rubella vaccination in Italy.

A Review of Respiratory Syncytial Virus Epidemiology Among Children: Linking Effective Prevention to Vulnerable Populations

Respiratory syncytial virus (RSV) is the greatest contributor to lower respiratory tract infections (LRTI) in children less than 5 years of age and the leading cause for infant hospitalizations in the United States (US). The burden of severe disease disproportionately impacts racial and ethnic minority groups, highlighting the need for interventions that promote health equity. Recent advancements in effective prophylactic agents have the potential to drastically alter the landscape of RSV disease among all young children. The effectiveness of prophylaxis, however, will rely on a clear understanding of RSV epidemiology. The purpose of this review is to discuss key aspects of RSV epidemiology while focusing on efforts to support equitable distribution of prophylactic agents to mitigate existing health disparities.

Hybrid Immunity to SARS-CoV-2 During Pregnancy Provides More Durable Infant Antibody Responses Compared to Natural Infection Alone

BACKGROUND

Hybrid immunity (infection plus vaccination) may increase maternally derived SARS-CoV-2 antibody responses and durability versus infection alone.

METHODS

Prospective cohort of pregnant participants with prior SARS-CoV-2 infection (anti-nucleocapsid IgG, RT-PCR, or antigen positive) and their infants had blood collected in pregnancy, at delivery/birth, and postpartum tested for anti-spike (anti-S) IgG and neutralizing antibodies (neutAb).

RESULTS

Among 107 participants at enrollment, 40% were unvaccinated and 60% were vaccinated (received ≥1 dose); 102 had previous SARS-CoV-2 infection in pregnancy (median, 19 weeks' gestation); 5 were diagnosed just prior to pregnancy (median, 8 weeks). At delivery, fewer unvaccinated participants (87% anti-S IgG+, 86% neutAb) and their infants (86% anti-S IgG+, 75% neutAb) had anti-S IgG+ or neutAb compared to vaccinated participants and their infants (100%, P ≤ .01 for all). By 3-6 months postpartum, 50% of infants of unvaccinated participants were anti-S IgG+ and 14% had neutAb, versus 100% among infants of vaccinated participants (all P < .01), with lower median antibody responses (anti-S IgG log10 1.95 vs 3.84 AU/mL, P < .01; neutAb log10 1:1.34 vs 1:3.20, P = .11).

CONCLUSIONS

In pregnant people with prior SARS-CoV-2, vaccination before delivery provided more durable maternally derived antibody responses than infection alone in infants through 6 months.

RSV Vaccination Intention Among People Who Are or Plan to Become Pregnant

OBJECTIVES

Respiratory syncytial virus (RSV) is a common pediatric infection, with young infants being at the highest risk of hospitalization and long-term sequela. New preventive agents have been recommended to prevent severe RSV illness in infants, including a vaccine administered during pregnancy. The current rates of recommended vaccination in pregnancy are suboptimal. Our objective was to characterize interest in RSV vaccination during pregnancy among people across the United States who were pregnant or planning to become pregnant.

METHODS

In March 2023, we conducted a national cross-sectional online survey of individuals 18 to 45 years old who were currently pregnant or trying to become pregnant on their perceptions of RSV-related illness and intentions to get vaccinated against RSV. We performed logistic regression analyses to determine the odds and predicted proportions of the likelihood of RSV vaccination during pregnancy, controlling for sociodemographic factors.

RESULTS

Of 1619 completed surveys, 1528 were analyzed. 54% of respondents indicated that they were "very likely" to get vaccinated against RSV during pregnancy. The perception of RSV as a serious illness was the strongest predictor of vaccination likelihood. In the full regression model, predicted proportions of "very likely" to vaccinate against RSV followed a similar pattern (63% if RSV infection was perceived as serious and likely, 55% if serious and unlikely, 35% if not serious; P < .001).

CONCLUSIONS

Raising awareness of RSV infection as likely and potentially serious for infants may be an influential component of targeted communications that promote RSV vaccine uptake during pregnancy.

COVID-19 Vaccine Acceptance in Pregnant Women in the United States: A Systematic Review and Meta-Analysis

Purpose: Pregnant women are vulnerable to Coronavirus Disease 2019 (COVID-19) complications, yet may hesitate to get vaccinated. It is important to identify racial/ethnic and other individual characteristics associated with COVID-19 vaccine acceptance in the United States during pregnancy. Methods: We searched PubMed, Embase, and Web of Science for articles published through January 2023 for keywords/terms related to immunization, COVID-19, and pregnancy, and performed a systematic review and meta-analysis to examine characteristics associated with vaccine acceptance. Results: Of 1,592 articles, 23 met inclusion criteria (focused on pregnant women in the United States, and their willingness or hesitation to vaccinate). Twenty-two of the studies examined receipt of ≥1 COVID-19 vaccine dose and/or intention to vaccinate, while one examined vaccine hesitancy. Vaccine acceptance rates ranged from 7% to 78.3%. Meta-analyses demonstrated that compared with Whites, Hispanics (odds ratios [OR] 0.72; 95% confidence interval [CI] 0.58-0.91) and Blacks (OR 0.44; 95% CI 0.30-0.63) had less COVID-19 vaccine acceptance, while Asians (OR 1.78; 95% CI 1.10-2.88) had greater vaccine acceptance. College graduation or more (OR 3.25; 95% CI 2.53-4.17), receipt or intention to receive the influenza vaccine (OR 3.46; 95% CI 2.22-5.41), and at least part-time employment (OR 2.12; 95% CI 1.66-2.72) were significantly associated with vaccine acceptance. Conclusions: COVID-19 vaccine nonacceptance in pregnant women is associated with Hispanic ethnicity and Black race, while acceptance is associated with Asian race, college education or more, at least part-time employment, and acceptance of the influenza vaccine. Future COVID-19 vaccination campaigns can target identified subgroups of pregnant women who are less likely to accept vaccination.

Attitudes and behaviors of maternal Tdap vaccination in Panama, Peru, and Colombia: An international cross-sectional study

INTRODUCTION

Despite a recommendation by PAHO for Tdap vaccination in pregnant women since 2019, uptake remains suboptimal across Latin America. This study evaluated the knowledge and attitudes of women towards maternal Tdap vaccination in Colombia, Peru, and Panama to identify the critical behavioral and social drivers of Tdap vaccine uptake during pregnancy.

METHODS

A cross-sectional online survey was undertaken between December 8, 2022, and January 11, 2023, targeting women in Colombia, Peru, or Panama with a child 12 months or under. We collected data on respondents' demographics, social and behavioral determinants of vaccine acceptance, determinants of vaccine uptake (using the validated 5As taxonomy), and previous vaccination experience.

RESULTS

In the 938 respondents who completed the survey (Panama, n = 325; Peru, n = 305; Colombia, n = 308), 73-80 % had received the influenza vaccine, whereas only 30-39 % had received a Tdap vaccine. Significant correlates of Tdap vaccine uptake common to all three countries included a health professional recommendation, knowledge of the vaccine and location of vaccination, perceived vulnerability to pertussis infection, perceived importance of immunization, and receipt of a reminder. In specific countries, nonvaccinated women were more likely to cite issues with ease of access (Panama, Colombia), affordability (opportunity costs; Peru, Colombia), and understanding the rationale for vaccination in pregnancy (Panama, Colombia).

CONCLUSION

To increase maternal Tdap vaccine uptake, health professionals should be encouraged to recommend vaccination consistently, and pregnant women should receive reminders explaining why and where to be vaccinated.

Uptake rates and attitudes to influenza and COVID-19 vaccination in pregnancy - a prospective cohort study

Influenza and COVID-19 are highly prevalent RNA viruses. Pregnancy increases the frequency of severe maternal morbidity and mortality associated with these viruses. Vaccination plays an important role in protecting pregnant women and their infants from adverse outcomes. In this prospective study, we aimed to determine the vaccination uptake rate for influenza and COVID-19 in a pregnant population and to explore reasons why women remained unvaccinated. A prospective cohort study was conducted over a two-week period in December 2022 in the National Maternity Hospital, Dublin. There were 588 women surveyed over the 2-week period. Overall, 377 (57%) were vaccinated that year for seasonal influenza, a significant rise from 39% in a similar study in 2016. The majority (n = 488, 83%) of women reported receiving at least one COVID-19 vaccine. However only 132 (22%) received a COVID-19 vaccine in pregnancy, despite 76% (n = 466) stating they would be happy to receive it. Factors such as age, obesity, co-morbidities, ethnic group, and type of antenatal care received were shown to influence vaccination rates. We recommend that the importance of vaccination be stressed regularly to eligible patients at their antenatal clinic visits and where possible combining influenza/COVID-19 vaccination on the same day to improve uptake.

Social determinants of health and vaccine uptake in pregnancy: Disparities in a diverse, predominately foreign-born population

OBJECTIVE

To identify discrepancies in influenza, Tdap, and COVID-19 vaccine uptake and offer rates among pregnant individuals across various social determinants of health including race, ethnicity, foreign-born status, education level, and health insurance coverage, highlighting potential interventions to improve vaccine uptake in pregnancy.

METHODS

An IRB-approved cross-sectional survey was conducted on the postpartum floor of a large urban hospital in South Florida. Between July to September 2021, 359 participants consented and answered questions on their demographics, social background, and influenza, Tdap, and COVID-19 vaccine history.

RESULTS

Most participants identified as White (67.7 %), Hispanic (67.4 %), and foreign-born (68.5 %) with an average age of 29.7 ± 6 years. There was a significant difference in mean vaccine between White (1.3) and Black individuals (0.9, p = 0.002). Mean uptake was significantly higher in foreign-born individuals (1.3) compared to US-born (0.9, p < 0.001). Mean uptake was significantly higher for those with graduate (1.7) and college (1.4) degrees compared to those with a high school degree (1.0) or less than high school (1.0, p < 0.0001).

CONCLUSION

Significant differences in the uptake and offer rates of influenza, Tdap, and COVID-19 vaccines were observed across a variety of social determinants including educational attainment, employment, insurance, and median income of the zip code of primary residence.

Subunit nanovaccine elicited T cell functional activation controls Trypanosoma cruzi mediated maternal and placental tissue damage and improves pregnancy outcomes in mice

This study investigated a candidate vaccine effect against maternal Trypanosoma cruzi (Tc) infection and improved pregnancy outcomes. For this, TcG2 and TcG4 were cloned in a nanoplasmid optimized for delivery, antigen expression, and regulatory compliance (nano2/4 vaccine). Female C57BL/6 mice were immunized with nano2/4, infected (Tc SylvioX10), and mated 7-days post-infection to enable fetal development during the maternal acute parasitemia phase. Females were euthanized at E12-E17 (gestation) days. Splenic and placental T-cell responses were monitored by flow cytometry. Maternal and placental/fetal tissues were examined for parasites by qPCR and inflammatory infiltrate by histology. Controls included age/immunization-matched non-pregnant females. Nano2/4 exhibited no toxicity and elicited protective IgG2a/IgG1 response in mice. Nano2/4 signaled a splenic expansion of functionally active CD4+ effector/effector memory (Tem) and central memory (Tcm) cells in pregnant mice. Upon challenge infection, nano2/4 increased the splenic CD4+ and CD8+T cells in all mice and increased the proliferation of CD4+Tem, CD4+Tcm, and CD8+Tcm subsets producing IFNγ and cytolytic molecules (PRF1, GZB) in pregnant mice. A balanced serum cytokines/chemokines response and placental immune characteristics indicated that pregnancy prevented the overwhelming damaging immune response in mice. Importantly, pregnancy itself resulted in a significant reduction of parasites in maternal and fetal tissues. Nano2/4 was effective in arresting the Tc-induced tissue inflammatory infiltrate, necrosis, and fibrosis in maternal and placental tissues and improving maternal fertility, placental efficiency, and fetal survival. In conclusion, we show that maternal nano2/4 vaccination is beneficial in controlling the adverse effects of Tc infection on maternal health, fetal survival, and pregnancy outcomes.

COVID-19 Vaccine Hesitancy among Unvaccinated Adults: A Cross-Sectional Exploratory Analysis of Vaccination Intentions in Italy Related to Fear of Infection

From the initial COVID-19 outbreak, Italy was the first Western country to be seriously affected by the pandemic. Understanding vaccine hesitancy can help efforts to achieve broad vaccination coverage. The objectives of this research were to determine the extent of vaccine hesitancy in Italy and to understand the characteristics of those segments of the population with some hesitancy. Between January and February 2021, 41,473 subjects answered the second questionnaire delivered in phase II of the web-based EPICOVID19 survey. Among the included adult volunteers living in Italy, 4653 (11.2%) reported having previously received at least one dose of the COVID-19 vaccine. In the sample of 36,820 respondents, all not vaccinated (age 51.1 ± 13.5; 59.7% female; 63.6% high level of education), the comparison between hesitant and inclined participants was accompanied by percentages and odds ratios. A total of 2449 individuals were hesitant (6.7% of the unvaccinated ones). Hesitancy was higher among women (OR = 1.48; 95%CI: 1.36-1.62); it was highest in the 50-59 and 40-49 age groups and among those with a lower educational level. A higher level of education was associated with a lower proportion of hesitancy (5.54%) compared with 9.44% among respondents with a low level of education (OR = 0.56; 95%CI: 0.46-0.68). Hesitancy was most common in subjects who did not report fear of infection (12.4%, OR = 4.0; 95%CI: 3.46-4.61). The results can guide the design of tailored information and communication campaigns through considering objective and subjective characteristics.

The pandemic experiences of Ontario perinatal providers: a qualitative study

BACKGROUND

The COVID-19 pandemic has produced widespread disruptions for healthcare systems across Canada. Perinatal care in Ontario, Canada was subject to province-wide public health restrictions, reallocation of hospital beds and human health resources. To better understand the impacts of the pandemic on Ontario perinatal care, this study explored the perspectives of perinatal care providers about their clinical COVID-19 pandemic experiences.

METHODS

Semi-structured key informant virtual interviews were conducted between August 2021 and January 2022 with 15 Ontario-based perinatal care providers. Recorded interviews were transcribed, and thematic content analysis used to identify major themes and subthemes.

RESULTS

Participants were mainly women, practicing in Eastern and Central Ontario as health providers (obstetricians, nurses, midwives), allied regulated health professionals (social worker, massage therapist), and perinatal support workers (doula, lactation consultant). Major themes and subthemes were identified inductively as follows: (1) Impacts of COVID-19 on providers (psychosocial stress, healthcare system barriers, healthcare system opportunities); (2) Perceived impacts of COVID-19 on pregnant people (psychosocial stress, amplification of existing healthcare barriers, influences on reproductive decision making; minor theme- social and emotional support roles); (3) Vaccine discourse (provider empathy, vaccines and patient family dynamics, minor themes- patient vaccine hesitancy, COVID-19 misinformation); and (4) Virtual pregnancy care (benefits, disadvantages, adaptation of standard care practices).

CONCLUSIONS

Perinatal care providers reported significant stress and uncertainty caused by the COVID-19 pandemic and evolving hospital protocols. Providers perceived that their patients were distressed by both the pandemic and related reductions in pregnancy healthcare services including hospital limits to support companion(s). Although virtual pregnancy care impaired patient-provider rapport, most providers believed that the workflow efficiencies and patient convenience of virtual care is beneficial to perinatal healthcare.

Vaccine hesitancy and knowledge regarding maternal immunization among reproductive age women in central Italy: a cross sectional study

Background

Vaccination in pregnancy offers protection to the mother and the newborn. In Italy, influenza, pertussis, and COVID-19 vaccinations are recommended in pregnancy, but vaccination coverage is still far from the National Immunization Plan goals. We aimed to assess knowledge and attitude on maternal immunization in two groups of Italian women, in pregnancy and in reproductive age (non pregnant).

Methods

A cross sectional study on Italian childbearing age women gathering information on their knowledge on maternal immunization and attitudes to receiving influenza and pertussis vaccines in pregnancy was carried out at the University of Rome Tor Vergata, between September 2019 and February 2020. Logistic and multinomial regressions were chosen as statistical tests for our analysis.

Results

1,031 women participated in the survey by answering the questionnaire. Out of these, 553 (53.6%) women were pregnant, and 478 (46.4%) were in the reproductive age. 37% (204/553) of pregnant women and 41% (198/476) of non pregnant women are aware of the existence of an immunization plan for pregnant women in Italy. The group with age between 20 and 30, for both pregnant women and women in the reproductive age, has a better knowledge of vaccination in pregnancy. Working status is a variable associated with more awareness about vaccination during pregnancy only for pregnant women (OR = 2.34, p < 0.00001). Educational status, trimester of pregnancy and knowledge on the topic are associated with vaccine hesitancy in our multivariate analysis for pregnant women. In the reproductive age group women who had a previous pregnancy are more likely to be hesitant towards vaccination in pregnancy, on the other hand the one with a higher knowledge and educational status are more likely to get vaccinated.

Conclusions

The study highlights the persistent vaccine hesitancy among Italian women of reproductive age and pregnant women. Despite healthcare providers being identified as a reliable source of information, their recommendations alone are insufficient to overcome vaccine hesitancy. Factors such as employment status, educational level, pregnancy trimester, and knowledge about vaccinations during pregnancy influence vaccine hesitancy. Tailored educational interventions and communication campaigns targeting these areas can help reduce vaccine hesitancy and promote maternal immunization.

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

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