Uptake of vaccination in pregnancy

Vaccination coverage during pregnancy and factors associated with refusal of recommended vaccinations: An Italian cross sectional study

Background

The vaccines recommended during pregnancy are the Tdap, the influenza vaccine, and, during the SARS-CoV-2 pandemic, the vaccine against COVID-19. This survey aimed at determining vaccination coverage among pregnant women and adverse events, reasons for vaccine refusal, and factors associated with vaccine uptake.

Methods

A single-center cross-sectional study was conducted on women who delivered between March and April 2022 at Careggi University Hospital in Florence, Italy. Information on the vaccinations (Tdap, influenza and COVID-19) received during pregnancy were collected through in-person interviews.

Results

Among 307 enrolled women (response rate 99 % on a study population of 310 eligible women), 74 % of patients were vaccinated with Tdap, 82 % against COVID-19, and only 33 % against influenza. Vaccination coverage for Tdap and COVID-19 was significantly higher among Italian than foreign patients (80 % vs 51 %, p < 0.001 and 86 % vs 69 %, p = 0.002, respectively), and for Tdap was higher among patients followed in the private vs public care setting. The main reasons behind refusal of vaccinations were low risk perception of influenza (41 %), insufficient information received from the prenatal care provider regarding the Tdap (35 %), and, for the COVID-19, fear of vaccine side effects (64 %), and concerns about effects on the fetus (70 %).

Conclusions

Adherence to the influenza vaccine was low because of reduced perception of the disease risks. The difference in vaccination coverage between Italians and foreigners is an example of healthcare disparity. Better information provided to patients about vaccines' efficacy and safety is advisable to increase acceptance of recommended vaccines.

The current state of pertussis vaccination in pregnancy around the world, with recommendations for improved care: Consensus statements from the Global Pertussis Initiative

Bordetella pertussis, which causes a respiratory disease known as pertussis ("whooping cough") remains an important global challenge, with the incidence in pertussis cases increasing in recent years. Newborns and infants are at increased risk for severe morbidity and mortality from this bacterium. Vaccination in pregnancy has become an important strategy to both passively transfer immunity as well as prevent infection in pregnant persons, who are a major source of newborn infection, thus attempting to decrease the impact of this serious disease. It is considered safe for the pregnant person, the developing fetus, and the infant, and during the first 3 months of life it has been shown to be highly effective in preventing pertussis. There are a variety of strategies, recommendations, and adherence rates associated with pertussis vaccination in pregnancy around the world. We summarize the 2021 Global Pertussis Initiative Annual Meeting that reviewed the current global status of pertussis vaccination in pregnancy and remaining medical and scientific questions, with a focus on vaccination challenges and strategies for obstetric and gynecologic healthcare providers.

COVID-19 vaccination in pregnancy: A quantitative and qualitative analysis of the effect of strong public health messaging in an Australian cohort

BACKGROUND

SARS-CoV-2 infection in pregnancy predisposes women and their offspring to adverse health outcomes, while internationally reported rates of vaccination uptake remain low. Our study objective was to quantify the uptake of COVID-19 vaccination in pregnant women, and to assess their attitudes toward vaccination in pregnancy with both quantitative and qualitative analyses.

MATERIALS AND METHODS

This is a prospective, cross-sectional survey at Australia's largest quaternary level maternity centre. A total of 351 pregnant women, at 6-42 weeks gestation receiving antenatal care at our hospital, completed an online voluntary, anonymous, 17 question survey. This was conducted during a five-week period in November to December 2021. The main outcome measures were demographic data, prior SARS-CoV-2 infection and COVID-19 vaccination status, knowledge and attitudes surrounding COVID-19 disease and vaccination in pregnancy.

RESULTS

High rates of COVID-19 vaccination were observed in this pregnant population. Of the 351 respondents, 82% had received at least one dose of the COVID 19-vaccination. This increased compared to estimates of 15% in June 2021 which were obtained from the hospital's electronic health record.

CONCLUSIONS

Our survey demonstrates that a strong public health campaign with clear messaging regarding the beneficial effects of COVID-19 vaccination in pregnancy can lead to high vaccination uptake rates.

Low dose aspirin prevents endothelial dysfunction in the aorta and foetal loss in pregnant mice infected with influenza A virus

Influenza A virus (IAV) infection in pregnancy resembles a preeclamptic phenotype characterised by vascular dysfunction and foetal growth retardation. Given that low dose aspirin (ASA) is safe in pregnancy and is used to prevent preeclampsia, we investigated whether ASA or NO-conjugated aspirin, NCX4016, resolve vascular inflammation and function to improve offspring outcomes following IAV infection in pregnant mice. Pregnant mice were intranasally infected with a mouse adapted IAV strain (Hkx31; 104 plaque forming units) and received daily treatments with either 200µg/kg ASA or NCX4016 via oral gavage. Mice were then culled and the maternal lungs and aortas collected for qPCR analysis, and wire myography was performed on aortic rings to assess endothelial and vascular smooth muscle functionality. Pup and placentas were weighed and pup growth rates and survival assessed. IAV infected mice had an impaired endothelial dependent relaxation response to ACh in the aorta, which was prevented by ASA and NCX4016 treatment. ASA and NCX4016 treatment prevented IAV dissemination and inflammation of the aorta as well as improving the pup placental ratios in utero, survival and growth rates at post-natal day 5. Low dose ASA is safe to use during pregnancy for preeclampsia and this study demonstrates that ASA may prove a promising treatment for averting the significant vascular complications associated with influenza infection during pregnancy.

Observational analysis of the immunogenicity and safety of various types of spinal muscular atrophy vaccines

BACKGROUND

This study aimed to evaluate the immunogenicity and safety of different types of poliovirus vaccines.

METHODS

A randomized, blinded, single-center, parallel-controlled design was employed, and 360 infants aged ≥ 2 months were selected as study subjects. They were randomly assigned to bOPV group (oral Sabin vaccine) and sIPV group (Sabin strain inactivated polio vaccine), with 180 infants in each group. Adverse reaction events in the vaccinated subjects were recorded. The micro-neutralization test using cell culture was conducted to determine the geometric mean titer (GMT) of neutralizing antibodies against poliovirus types I, II, and III in different groups, and the seroconversion rates were calculated.

RESULTS

Both groups exhibited a 100% seropositivity rate after booster immunization. The titers of neutralizing antibodies for the three types were predominantly distributed within the range of 1:128 to 1:512. The fold increase of type I antibodies differed markedly between the two groups (P < 0.05). Moreover, the fold increase of type II and type III antibodies for poliovirus differed slightly between the two groups (P > 0.05). The fourfold increase rate in sIPV group was drastically superior to that in bOPV group (P < 0.05). When comparing the post-immunization GMT levels of type I antibodies in individuals who completed the full course of spinal muscular atrophy vaccination, bOPV group showed greatly inferior levels to sIPV group (P < 0.05). For type II and type III antibodies, individuals in bOPV group demonstrated drastically superior post-immunization GMT levels to those in sIPV group (P < 0.05). The incidence of adverse reactions between the bOPV and sIPV groups differed slightly (P > 0.05).

CONCLUSION

These findings indicated that both the oral vaccine and inactivated vaccine had good safety and immunogenicity in infants aged ≥ 2 months. The sIPV group generated higher levels of neutralizing antibodies in serum, particularly evident in the post-immunization GMT levels for types II and III.

Influenza vaccine during pregnancy, recommendations from healthcare providers, and race/ethnicity in the United States

OBJECTIVES

We examined racial/ethnic differences in the association between influenza vaccine recommendations from healthcare providers and maternal vaccination uptake.

METHODS

This cross-sectional study examined data from the Pregnancy Risk Assessment Monitoring System. We categorized respondents as non-Hispanic (NH) Whites, NH-Blacks, NH-Asians, American Indians/Alaska Natives, NH Other non-Whites, and Hispanics. We conducted multivariable logistical regression models to evaluate adjusted odds ratios (AOR) and 95% confidence intervals (CI). Covariates included maternal age, marital status, education, insurance status before pregnancy, the number of previous live births, the number of prenatal care visits, and smoking status during pregnancy.

RESULTS

The prevalences of receiving influenza vaccine recommendations from healthcare providers and maternal vaccine were 80.01% and 50.42%, respectively. NH-Blacks are less likely to receive provider recommendations (AOR = 0.82; 95%CI 0.77-0.87) and be vaccinated (AOR = 0.76; 95%CI 0.72-0.80) than NH-Whites. Receiving provider recommendations was significantly associated with increased maternal influenza vaccine uptake (AOR = 15.50; 95% CI 14.51-16.55). The associations were significant for all racial/ethnic groups, with the highest among NH-Asians (AOR = 22.04; 95% CI 17.88-27.16) and the lowest among NH Other non-Whites (AOR = 11.07; 95% CI 8.25-14.86). Within NH-Asians, effectiveness among Chinese was highest (AOR = 29.39; 95% CI 18.10-47.71).

CONCLUSIONS

Racial/ethnic disparities in maternal influenza vaccine uptake and receiving vaccine recommendations from healthcare providers persisted. Further studies on the racial/ethnic disparities in maternal vaccination were warranted and tailored strategies are required to reduce this health disparity.

Vaccination Guidelines for Pregnant Women: Addressing COVID-19 and the Omicron Variant

Vaccinations are an essential element of public health programs around the world, which have a major impact on morbidity, mortality, and costs of the health care system. In recent years, with a better understanding of the effectiveness and safety of vaccinations, many recommendations have been developed for administering vaccines to adults. Countless physiological changes occur during pregnancy, including those affecting the immune system. Pregnant women are at increased risk of developing infections and resulting complications. According to research, vaccines are immunogenic and safe for pregnant women. Pregnancy is not an absolute contraindication to vaccination. After administration of vaccines to pregnant women, the concentration of antibodies increases, which can be transferred to the child in the second and third trimesters of pregnancy and provide protection in the first months of life. The Advisory Committee on Immunization Practices (ACIP), guidelines of the Centers for Disease Control and Prevention (CDC), and the American College of Obstetrics and Gynecology (ACOG) unanimously recommend vaccination of pregnant women if a safe vaccine is available and there is a risk of exposure of the woman to a disease that threatens herself or her developing baby. In everyday clinical practice, medical professionals should provide their patients with the necessary information on vaccinations, which may contribute to greater awareness and implementation of vaccinations. This article aims to review current global recommendations for the vaccination of pregnant and breastfeeding women, including against the Omicron variants of SARS-CoV-2.

Vaccination during pregnancy: A golden opportunity to embrace

Immunization strategies are part of routine pregnancy care to prevent infectious diseases in the mother, the fetus, and the newborn. Maternal immunization recommendations followed the recognition of the consequences of infectious diseases in pregnancy, including vertical transmission and perinatal consequences. The recent COVID-19 pandemic highlighted the issue of vaccination among pregnant individuals. Recommendations vary globally; however, Tdap, influenza, and, recently, COVID-19 vaccines are routinely recommended during pregnancy. There are several new maternal immunization products in the pipeline, including those directed against malaria, cytomegalovirus, Group B Streptococcus, herpes simplex virus, and respiratory syncytial virus. Important challenges must be addressed in all countries to guarantee that pregnant individuals and their babies receive the best care possible, including uptake of recommended immunizations by their entire target population groups. These challenges include disseminating appropriate data for vaccine recommendations and many others, such as ensuring stakeholder endorsement, achieving in-country distribution and administration, adequate vaccine supply, and a well-organized healthcare system, ideally offering the immunization free of charge. More recently, the hesitancy of pregnant women to receive immunizations highlights the relevance of cultural aspects and other contextual factors affecting vaccine uptake among pregnant individuals.

Adverse outcomes in SARS-CoV-2-infected pregnant mice are gestational age-dependent and resolve with antiviral treatment

SARS-CoV-2 infection during pregnancy is associated with severe COVID-19 and adverse fetal outcomes, but the underlying mechanisms remain poorly understood. Moreover, clinical studies assessing therapeutics against SARS-CoV-2 in pregnancy are limited. To address these gaps, we developed a mouse model of SARS-CoV-2 infection during pregnancy. Outbred CD1 mice were infected at E6, E10, or E16 with a mouse-adapted SARS-CoV-2 (maSCV2) virus. Outcomes were gestational age-dependent, with greater morbidity, reduced antiviral immunity, greater viral titers, and impaired fetal growth and neurodevelopment occurring with infection at E16 (third trimester equivalent) than with infection at either E6 (first trimester equivalent) or E10 (second trimester equivalent). To assess the efficacy of ritonavir-boosted nirmatrelvir, which is recommended for individuals who are pregnant with COVID-19, we treated E16-infected dams with mouse-equivalent doses of nirmatrelvir and ritonavir. Treatment reduced pulmonary viral titers, decreased maternal morbidity, and prevented offspring growth restriction and neurodevelopmental impairments. Our results highlight that severe COVID-19 during pregnancy and fetal growth restriction is associated with heightened virus replication in maternal lungs. Ritonavir-boosted nirmatrelvir mitigated maternal morbidity along with fetal growth and neurodevelopment restriction after SARS-CoV-2 infection. These findings prompt the need for further consideration of pregnancy in preclinical and clinical studies of therapeutics against viral infections.

A study of acceptance and hesitation factors towards tetanus, diphtheria, and acellular pertussis (Tdap) and influenza vaccines during pregnancy

Introduction

Vaccination of pregnant women with tetanus, diphtheria, and acellular pertussis (Tdap) and influenza vaccines is desirable to reduce neonatal and maternal morbidity and mortality. However, vaccine coverage rates and acceptance are frequently below recommended rates.

Objectives

To ascertain Tdap and influenza vaccine coverage rates in our population and to study the reasons behind sub-optimal rates.

Method

A survey was submitted to pregnant or in their puerperium women at the University Hospital of São Paulo University. Data were obtained during two consecutive influenza seasons (2017-2018), and vaccination was verified through vaccination chart checking. Respondents were classified according to their status as "Received Tdap" and "Didn't receive Tdap", and as "Know" or "Doesn't know" regarding their awareness of Tdap safety during pregnancy and protective effect on the newborn. Vaccine uptake and personal awareness of vaccination status were compared among these groups for Tdap and influenza vaccines.

Results

In a studied sample of 207 patients (representative of the whole), coverage rates for Tdap and influenza vaccines were respectively 85.5% and 95.2%. Additionally, 84.5% received both vaccines. There was no vaccine refusal for Tdap and only 0.5% for influenza. For either Tdap or influenza vaccines, the main reason for not vaccinating was a lack of knowledge/information. Factors associated with not vaccinating Tdap during pregnancy were lower number of prenatal visits, being unemployed or freelance worker, not being aware of vaccine safety or its benefits for the baby, not being oriented by the doctor to be vaccinated, not being aware of personal vaccination status, and not having been vaccinated for influenza.

Conclusion

While influenza vaccination coverage during pregnancy was ideal, Tdap rates were below recommended values. Significant factors associated with better coverage for Tdap during pregnancy included being employed and not being self-employed, (not yet reported in the Americas) and being aware of personal vaccination status.

Impact of Obesity and Diabetes in Pregnant Women on Their Immunity and Vaccination

Pregnant women with obesity and diabetes are at increased risk of developing infections and other complications during pregnancy. Several mechanisms are involved in the immunological mechanisms that contribute to reduced immunity in these populations. Both obesity and diabetes are associated with chronic low-grade inflammation that can lead to an overactive immune response. Pregnant women with obesity and diabetes often have an increase in pro-inflammatory cytokines and adipokines, such as TNF-α, IL-6, IL-1β, leptin, and resistin, which are involved in the inflammatory response. Insulin resistance can also affect the functioning of immune cells. Furthermore, both conditions alter the composition of the gut microbiome, which produces a variety of biomolecules, including short-chain fatty acids, lipopolysaccharides, and other metabolites. These substances may contribute to immune dysfunction. In addition to increasing the risk of infections, obesity and diabetes can also affect the efficacy of vaccinations in pregnant women. Pregnant women with obesity and diabetes are at increased risk of developing severe illness and complications from COVID-19, but COVID-19 vaccination may help protect them and their fetuses from infection and its associated risks. Since both obesity and diabetes classify a pregnancy as high risk, it is important to elucidate the impact of these diseases on immunity and vaccination during pregnancy. Research examining the efficacy of the COVID-19 vaccine in a high-risk pregnant population should be of particular value to obstetricians whose patients are hesitant to vaccinate during pregnancy. Further research is needed to better understand these mechanisms and to develop effective interventions to improve immune function in these populations.

Adverse outcomes in SARS-CoV-2 infected pregnant mice are gestational age-dependent and resolve with antiviral treatment

SARS-CoV-2 infection during pregnancy is associated with severe COVID-19 and adverse fetal outcomes, but the underlying mechanisms remain poorly understood. Moreover, clinical studies assessing therapeutics against SARS-CoV-2 in pregnancy are limited. To address these gaps, we developed a mouse model of SARS-CoV-2 infection during pregnancy. Outbred CD1 mice were infected at embryonic day (E) 6, E10, or E16 with a mouse adapted SARS-CoV-2 (maSCV2) virus. Outcomes were gestational age-dependent, with greater morbidity, reduced anti-viral immunity, greater viral titers, and more adverse fetal outcomes occurring with infection at E16 (3rd trimester-equivalent) than with infection at either E6 (1st trimester-equivalent) or E10 (2nd trimester-equivalent). To assess the efficacy of ritonavir-boosted nirmatrelvir (recommended for pregnant individuals with COVID-19), we treated E16-infected dams with mouse equivalent doses of nirmatrelvir and ritonavir. Treatment reduced pulmonary viral titers, decreased maternal morbidity, and prevented adverse offspring outcomes. Our results highlight that severe COVID-19 during pregnancy and adverse fetal outcomes are associated with heightened virus replication in maternal lungs. Ritonavir-boosted nirmatrelvir mitigated adverse maternal and fetal outcomes of SARS-CoV-2 infection. These findings prompt the need for further consideration of pregnancy in preclinical and clinical studies of therapeutics against viral infections.

Vaccination against influenza in pregnant women in a maternity hospital in the Czech Republic in the season 2020-2021

OBJECTIVES

Pregnant women are among the priority groups to receive influenza vaccines in the Czech Republic since 2011, data on vaccination coverage are not yet available. The aim of the study was to determine the influenza vaccination coverage (IVC) and provide source data for further activities.

METHODS

A prospective observational study was performed in a large maternity hospital in Prague. The self-completed questionnaire was distributed to 5,475 pregnant women between September 1, 2020 and August 31, 2021. Questions included maternal sociodemographic characteristics, influenza vaccination status and sources of maternal vaccination recommendations during pregnancy.

RESULTS

A total of 4,617 completed questionnaires have been analysed. The median age of study participants (N = 4,592) was 33 years (range: 18-51 years). The majority (69.7%) of women had completed their university education, most women were childless (58.5%) or had one child (32.5%) before the start of the study. Less than 2% of women reported being vaccinated against influenza during their pregnancy (1.5%; 95% CI, 1.1-1.9%). Only 21% of women knew that it's possible to get vaccinated against influenza during pregnancy. Participants considered influenza vaccination in pregnancy as important (3.3%), useful (41.1%) and useless (44.4%). Out of 959 pregnant women who had information about influenza vaccination during pregnancy, only 6.9% were vaccinated, while among those who did not have this information, 0.1% were vaccinated during pregnancy (p < 0.001). The most frequent source of information was Internet, then media and a general practitioner.

CONCLUSIONS

The IVC during pregnancy in our study was extremely low. In order to improve IVC among pregnant women, it is necessary to increase awareness of recommendations and vaccination options among the public and professionals and incorporating vaccination recommendation in routine antenatal practice.

Acceptance of vaccination against pertussis, COVID-19 and influenza during pregnancy: a cross-sectional study

Background

This study aims to assess the uptake of maternal pertussis and COVID-19 vaccination and the intention towards accepting the maternal influenza vaccination. Insights into different socio-demographic factors related to maternal vaccination coverage might help to address vaccine acceptance and improve maternal vaccine uptake in the future.

Methods

We conducted a cross-sectional survey among pregnant women and recent mothers, up to 6 months post-partum. The primary outcome measures of this study were behaviour for maternal pertussis and COVID-19 vaccination, and maternal influenza vaccination intention. Associations between socio-demographic factors and maternal pertussis vaccination and maternal COVID-19 vaccination behaviour; and socio-demographic factors and maternal influenza vaccination intention were assessed using binary logistic regression analyses.

Results

In total 1361 respondents filled out the questionnaire. Almost all women (95%) were vaccinated against pertussis during pregnancy, while almost two-third were vaccinated against COVID-19 during pregnancy (58%) and almost one-third (28%) had a positive intention towards receiving the maternal influenza vaccination. Results show that young maternal age and low education level were associated with lower maternal vaccination acceptance.

Conclusion

Vaccination campaigns focusing on the severity of diseases that are prevented, are needed to increase maternal vaccine acceptance in younger and low-educated pregnant women. We expect that differences in vaccination coverage between the three maternal vaccinations might partly be explained by existing recommendations, campaigns and whether the vaccination is part of the national immunisation program.

A Sensitive Public Health Issue—The Vaccine Acceptancy and the Anti-Pertussis Immune Status of Pregnant Women from a Romanian Metropolitan Area

(1) Background: Immunization of pregnant women (PWs) against Bordetella pertussis infection is still a challenging health matter. (2) Methods: We gathered questionnaire data from 180 PWs regarding their expectancies and current opinion on infectious disease prevention. For the group of PWs who agreed to further investigations, the serum levels of Ig G anti-B. pertussis antibodies (IgG-PT) titer were measured and analyzed. (3) Results: A total of 180 PWs completed the questionnaire and 98 (54.44%, study group) accepted to perform the laboratory tests. During the first two pregnancy trimesters, PWs were found to be more willing (compared with the control group) to test for identifying high-risk situations that could affect themselves and their future infant (p < 0.001). Most of the participating PWs (91, 91.9%) had low levels of anti-pertussis antibodies (values < 40 IU/mL). Declared vaccine coverage of the PWs newborn infants for DTaP-1 and Prevenar 13 (at 2 months) and DTaP-2 and Prevenar 13 (at 4 months) vaccination reached 100% in the study group, while in the control group only 30/82 (36.59%) PWs accepted to be vaccinated during pregnancy, none of them providing data on their infants’ vaccine coverage. (4) Conclusions: Enrolled PWs faced a waning immunity against the B. pertussis infection. By raising maternal confidence in the protective role of vaccines against infectious diseases, better vaccine acceptance and better infant vaccine coverage can be achieved.

Temporal trends and determinants of COVID-19 vaccine coverage and series initiation during pregnancy in Ontario, Canada, December 2020 to December 2021: A population-based retrospective cohort study

BACKGROUND

Population-based COVID-19 vaccine coverage estimates among pregnant individuals are limited. We assessed temporal patterns in vaccine coverage (≥1 dose before or during pregnancy) and evaluated factors associated with vaccine series initiation (receiving dose 1 during pregnancy) in Ontario, Canada.

METHODS

We linked the provincial birth registry with COVID-19 vaccination records from December 14, 2020 to December 31, 2021 and assessed coverage rates among all pregnant individuals by month, age, and neighborhood sociodemographic characteristics. Among individuals who gave birth since April 2021-when pregnant people were prioritized for vaccination-we assessed associations between sociodemographic, behavioral, and pregnancy-related factors with vaccine series initiation using multivariable regression to estimate adjusted risk ratios (aRR) and risk differences (aRD) with 95% confidence intervals (CI).

RESULTS

Among 221,190 pregnant individuals, vaccine coverage increased to 71.2% by December 2021. Gaps in coverage across categories of age and sociodemographic characteristics decreased over time, but did not disappear. Lower vaccine series initiation was associated with lower age (<25 vs. 30-34 years: aRR 0.53, 95%CI 0.51-0.56), smoking (vs. non-smoking: 0.64, 0.61-0.67), no first trimester prenatal care visit (vs. visit: 0.80, 0.77-0.84), and residing in neighborhoods with the lowest income (vs. highest: 0.69, 0.67-0.71). Vaccine series initiation was marginally higher among individuals with pre-existing medical conditions (vs. no conditions: 1.07, 1.04-1.10).

CONCLUSIONS

COVID-19 vaccine coverage among pregnant individuals remained lower than in the general population, and there was lower vaccine initiation by multiple characteristics.

Influence of the COVID-19 pandemic and social media on the behaviour of pregnant and lactating women towards vaccination: a scoping review

BACKGROUND

Pregnant women, foetuses and infants are at risk of infectious disease-related complications. Maternal vaccination is a strategy developed to better protect pregnant women and their offspring against infectious disease-related morbidity and mortality. Vaccines against influenza, pertussis and recently also COVID-19 are widely recommended for pregnant women. Yet, there is still a significant amount of hesitation towards maternal vaccination policies. Furthermore, contradictory messages circulating social media impact vaccine confidence.

OBJECTIVES

This scoping review aims to reveal how COVID-19 and COVID-19 vaccination impacted vaccine confidence in pregnant and lactating women. Additionally, this review studied the role social media plays in creating opinions towards vaccination in these target groups.

ELIGIBILITY CRITERIA

Articles published between 23 November 2018 and 18 July 2022 that are linked to the objectives of this review were included. Reviews, articles not focusing on the target group, abstracts, articles describing outcomes of COVID-19 infection/COVID-19 vaccination were excluded.

SOURCES OF EVIDENCE

The PubMed database was searched to select articles. Search terms used were linked to pregnancy, lactation, vaccination, vaccine hesitancy, COVID-19 and social media.

CHARTING METHODS

Included articles were abstracted and synthesised by one reviewer. Verification was done by a second reviewer. Disagreements were addressed through discussion between reviewers and other researchers.

RESULTS

Pregnant and lactating women are generally less likely to accept a COVID-19 vaccine compared with non-pregnant and non-nursing women. The main reason to refuse maternal vaccination is safety concerns. A positive link was detected between COVID-19 vaccine willingness and acceptance of other vaccines during pregnancy. The internet and social media are identified as important information sources for maternal vaccination.

DISCUSSION AND CONCLUSION

Vaccine hesitancy in pregnant and lactating women remains an important issue, expressing the need for effective interventions to increase vaccine confidence and coverage. The role social media plays in vaccine uptake remains unclear.

A Live Attenuated COVID-19 Candidate Vaccine for Children: Protection against SARS-CoV-2 Challenge in Hamsters

Children are at risk of infection from severe acute respiratory syndrome coronavirus-2 virus (SARS-CoV-2) resulting in coronavirus disease (COVID-19) and its more severe forms. New-born infants are expected to receive short-term protection from passively transferred maternal antibodies from their mothers who are immunized with first-generation COVID-19 vaccines. Passively transferred antibodies are expected to wane within first 6 months of infant's life, leaving them vulnerable to COVID-19. Live attenuated vaccines, unlike inactivated or viral-protein-based vaccines, offer broader immune engagement. Given effectiveness of live attenuated vaccines in controlling infectious diseases such as mumps, measles and rubella, we undertook development of a live attenuated COVID-19 vaccine with an aim to vaccinate children beyond 6 months of age. An attenuated vaccine candidate (dCoV), engineered to express sub-optimal codons and deleted polybasic furin cleavage sites in the spike protein of the SARS-CoV-2 WA/1 strain, was developed and tested in hamsters. Hamsters immunized with dCoV via intranasal or intramuscular routes induced high levels of neutralizing antibodies and exhibited complete protection against the SARS-CoV-2 wild-type isolates, i.e., the Wuhan-like (USA-WA1/2020) and Delta variants (B.1.617.2) in a challenge study. In addition, the dCoV formulated with the marketed measles-rubella (MR) vaccine, designated as MR-dCoV, administered to hamsters via intramuscular route, also protected against both SARS-CoV-2 challenges, and dCoV did not interfere with the MR vaccine-mediated immune response. The safety and efficacy of the dCoV and the MR-dCoV against both variants of SARS-CoV-2 opens the possibility of early immunization in children without an additional injection.

Modern Approaches in Immunoprophylaxis of Infectious Diseases During Pregnancy

Every year more countries recommend vaccination for pregnant women. Nowadays, the spectrum of vaccines that can be used during pregnancy is expanding. Experts of the Union of Pediatricians of Russia have completely updated the section about the pregnant women immunoprophylaxis within updating clinical guidelines on normal pregnancy management. This section is presented in the following article.

Safety of COVID-19 vaccination in women undergoing IVF/ICSI treatment - Clinical study and systematic review

Background

It was suggested that vaccination in general might affect reproductive health. Safety of COVID-19 vaccination in women undergoing assisted reproductive techniques (ART) treatment is not well established.

Methods

We performed a retrospective study including 536 women undergoing fresh embryo transfer after IVF/ICSI treatment in a huge IVF center in southern China to investigate the effect of COVID-19 vaccination on oocyte maturation, fertilization rate, blastulation rate, implantation rate, clinical pregnancy rate and miscarriage rate. In addition, we performed a systematic review of existing studies on the safety of COVID-19 vaccination in women undergoing ART treatment.

Results

In our study, 268 women received inactivated or recombinant COVID-19 vaccination and 268 controls were enrolled based on propensity score matching. We observed a decreased fertilization rate and signs for impaired oocyte maturation in vaccinated women. Besides our study, there were 15 studies analyzing the safety of COVID-19 vaccination in women undergoing ART treatment. For the mRNA vaccines, no adverse signals were reported concerning oocyte maturation, fertilization rate, blastulation rate, implantation rate, clinical pregnancy rate and miscarriage rate. In women being vaccinated with an inactivated vaccine, implantation rate, clinical pregnancy rate and miscarriage rate were not affected, whereas oocyte maturation and fertilization rate were impaired.

Conclusions

Vaccination against COVID-19 in women undergoing ART treatment seems to be safe especially for women getting mRNA vaccines. The effects on oocyte maturation and fertilization rate of inactivated and recombinant COVID-19 vaccinations might be a safety signal and need further investigation and independent confirmation.

Best practices in prenatal health promotion: Perceptions, experiences, and recommendations of Ottawa, Canada, prenatal key informants

BACKGROUND

Prenatal health promotion includes the provision of evidence-based information and practical skills to optimize maternal-fetal outcomes. Increasingly, prenatal education is delivered by both healthcare professionals and allied childbirth educators, in community- or hospital-based group classes, targeted outreach programs, and online modules.

OBJECTIVES

To better understand how prenatal health promotion relates to a diverse urban community, we assessed the perspectives of Ottawa, Canada prenatal key informants.

DESIGN

This is a qualitative research with key informant interviews.

METHODS

Semi-structured interviews were conducted with 11 prenatal key informants, responsible for the design, delivery, or promotion of publicly available prenatal health services. Interviews explored concepts and delivery of prenatal health promotion, strategies to address existing and emerging prenatal topics, identification of barriers to prenatal health services, and recommendations.

RESULTS

Key informants recommended a lifespan approach to prenatal health promotion, with an emphasis on healthy behaviors, emotional health, labor and delivery, and postpartum/early parenting. Recognizing community health disparities, key informants used community outreach, and intersectoral collaborations for Indigenous and other at-risk communities to mitigate barriers to prenatal service uptake.

CONCLUSIONS

Ottawa key informants conceptualized prenatal health promotion as inclusive, comprehensive, and as an extension of preconception, school-based sexual education. Respondents recommended the design and delivery of prenatal interventions as culturally safe and trauma informed, using online modalities to complement in-person activities. The experience and intersectoral networks of community-based prenatal health promotion programs represent potential capacity to address emergent public health risks to pregnancy, particularly among at-risk populations.

PLAIN LANGUAGE SUMMARY

A broad and diverse community of professionals deliver prenatal education to help people have healthy babies. We interviewed Ottawa, Canada experts in prenatal care/education to learn about the design and delivery of reproductive health promotion. We found that Ottawa experts emphasized healthy behaviors beginning before conception and through pregnancy. Community outreach was identified as a successful strategy to promote prenatal education to marginalized groups.

COVID-19 Vaccine Hesitancy among Pregnant Women Attending Antenatal Clinics in Pakistan: A Multicentric, Prospective, Survey-Based Study

This study aimed to assess the vaccination status and factors contributing to vaccine hesitancy among pregnant women in the largest province of Pakistan. A multicentric, prospective, survey-based study using an interviewer-administered tool was conducted among pregnant women attending antenatal clinics between 1 December 2021 through 30 January 2022 across seven hospitals in Pakistan. The healthcare professionals providing care at the participating hospitals administered the survey. Four hundred and five pregnant women fully consented and completed the study. The majority of the study participants (70.6%, n = 286) were aged between 25 and 34 and had a previous successful pregnancy history. More than half of the study participants (56.0%, n = 227) did not receive COVID-19 vaccination at the time of data collection despite their family members (93.9%, n = 372) had already received at least one dose of COVID-19 vaccine. Among those who received COVID-19 vaccination (n = 173), vaccine efficacy, protection for the foetus, and risk of COVID-19-associated hospitalisation were the main driving factors for vaccine hesitancy. The majority of the unvaccinated women (77.8%, n = 182) had no intention of receiving the vaccine. However, more than two-thirds (85.7%, n = 342) consulted the doctor about COVID-19 vaccines, and most were recommended to receive COVID-19 vaccines by the doctors (80.7%, n = 280). Women were significantly more likely to be vaccinated if they had employment (odds ratio [OR] 4.47, 95% confidence interval [CI]: 2.31-8.64) compared with their counterparts who were homemakers, consulted their doctors (OR 0.12, 95% CI: 0.04-0.35), and if they did not have pregnancy-related issues (OR 6.02, 95% CI: 2.36-15.33). In this study, vaccine hesitancy was prevalent, and vaccine uptake was low among pregnant women. Education and employment did impact COVID vaccination uptake, emphasising the need for more targeted efforts to enhance the trust in vaccines.

Written Briefing and Oral Counseling Increase the Willingness to Receive the SARS-CoV-2 Vaccination among Women in Puerperium: A Qualitative Prospective Cohort Study

(1) Background: Vaccination rates for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) are low in Austria. International obstetric societies recommend the SARS-CoV-2 mRNA vaccination for women in puerperium. (2) Methods: A prospective two-stage cohort study was conducted at the Medical University of Vienna between October 2022 and December 2022. Firstly, women in puerperium were assigned to the evaluation group (step 1), and secondly, another cohort of unvaccinated women were randomly assigned to study group A (written briefing) or B (written and oral briefing) (step 2). We evaluated the vaccination status among women in the evaluation group and the willingness to receive the vaccination in all three cohorts. (3) Results: We included 217 women in puerperium (evaluation: n = 69, A: n = 68; B: n = 80). In the evaluation group, 66.7% (n = 46/69) of the women were unvaccinated. A total of 45.7% (21/46) of the unvaccinated women categorically declined the SARS-CoV-2 vaccination. A total of 26.5% (n = 18/68) of women in study group A, and 43.8% (n = 35/80) of women in study group B expressed their willingness to receive the vaccination (p = 0.029). There were no differences in willingness to receive the vaccination between different age strata of women in study groups A and B. (D) Conclusion: Our qualitative data demonstrate a benefit from oral counseling in addition to written briefing in order to increase the willingness to receive the vaccination among women in puerperium.

COVID-19 Vaccines Confer Protection in Hospitalized Pregnant and Postpartum Women with Severe COVID-19: A Retrospective Cohort Study

The coronavirus disease 2019 (COVID-19) pandemic has had deleterious effects among the obstetric population. Pregnant and postpartum women constitute a high-risk group for severe COVID-19. Vaccination reduces the risk of infection, but it is not known whether women who become infected despite vaccination have a milder course of disease than those who had not been vaccinated. This retrospective cohort study evaluated whether vaccination reduces the severity of COVID-19 infection, as measured by severe maternal morbidity and mortality among hospitalized pregnant and postpartum individuals. A total of 2284 pregnant and postpartum women hospitalized with severe COVID-19 were included. Those who did and who did not receive COVID-19 vaccination were compared. The rates of intensive care unit admission, intubation, and mortality were significantly lower among subjects in the vaccinated group (p < 0.001, p < 0.001 and p < 0.001, respectively). The numbers of patients who needed to be vaccinated to avoid one case of intensive care unit admission, intubation, or death due to COVID-19 were 7, 7, and 9, respectively. The COVID-19 vaccine offers protective effects against intensive care unit admission, intubation, and death in hospitalized pregnant and postpartum women with severe SARS-CoV-2-induced SARS.

Knowledge attitudes and practices toward seasonal influenza vaccine among pregnant women during the 2018/2019 influenza season in Tunisia

Background

The uptake and acceptance of the influenza vaccine (IV) among pregnant women remain unknown in Tunisia despite the increased influenza-related complications and death. The present study aimed to assess the IV uptake and acceptability and to describe related knowledge and attitudes among pregnant women in Tunisia.

Methods

A cross-sectional study was conducted in 84 Tunisian healthcare facilities over a period of three months (from March to May 2019). All pregnant women aged ≥18 years who sought antenatal care in related health structures were included in this study based on a multistage self-weighted sampling. We measured knowledge and attitudes towards the IV and assessed factors related to willingness for its uptake.

Results

The questionnaire was completed by 1157 pregnant women. More than half of the participants (60.2%; 95% confidence interval [CI] [57.3%–63.0%]) reported awareness about the IV. Among included PW, only 4.6%; 95% CI [3.5%–6.1%] received it during their current pregnancy. However, (36.8%; 95% CI [34.0%–39.6%]) declared their willingness to receive the vaccine in the next pregnancy. Recommendation by healthcare providers, identified to be the most trustful source of information, was the main reason for acceptance. However, the intention to accept the IV by pregnant women was significantly associated with such recommendation and perceived safety and effectiveness of this vaccine.

Conclusion

Antenatal care visits are a precious opportunity that should not be missed by health care providers and especially gynecologists to promote the IV uptake by pregnant women in Tunisia.

Influenza and Pertussis Maternal Vaccination Coverage and Influencing Factors in Spain: A Study Based on Primary Care Records Registry

The purpose was to determine the coverage of maternal vaccination against influenza and pertussis, and the characteristics associated with being vaccinated, in a health area of Catalonia, Spain. Some 36,032 anonymized and computerized clinical records registries of pregnant women from Primary Care Centres (e-CAP database) were analysed, from between 2015 and 2018. Vaccination coverage and the association with sociodemographic variables and clinical conditions were estimated using a Poisson regression model. Maternal vaccination coverage against influenza ranged between 11.9% in 2015 and 6.8% in 2018, following a decreasing trend (p < 0.001). Coverage with the tetanus toxoid, diphtheria toxoid, and acellular pertussis vaccine varied between 49.8% in 2016 and 79.4% in 2018, following an increasing trend (p < 0.001). Having living children and suffering from obesity were factors associated with not being vaccinated against both infections. The predictive variables of vaccination against influenza were diabetes (IRR: 2.17, 95% CI: 1.42−3.30) and asthma (IRR: 2.05, 95% CI: 1.76−2.38); and for pertussis, it was asthma (IRR: 1.10, 95% CI: 1.03−1.17). Different socio-demographic factors and chronic conditions in pregnant women were associated with maternal vaccination, and which will have to be taken into account in clinical practice when implementing strategies to improve the coverage of the programme.

COVID-19 and Pregnancy

It is of greatest concern how COVID-19 is affecting pregnancy, mothers, and babies. Scientists are studying the impact of COVID-19 on pregnant women and babies and are understanding a little more every day. Reports show that there is an increased risk in pregnant women compared to nonpregnant women to get more serious illness due to COVID-19. Researchers are also investigating COVID-19 and its potential impact on a fetus. There are exceedingly rare cases of COVID-19 transmission to the fetus, and newborns can pick up COVID-19 when exposed. Vaccines are proved to be safe for pregnant women and help prevent both mother and the fetus from getting COVID-19 and are also highly effective to prevent COVID-19 infection, critical sickness, and fatalities in general. There are specific guidelines for labor and delivery during the COVID-19 pandemic which are to be imposed and followed to achieve safer and healthier childbirth. In this article, the overall influence of COVID-19 in pregnancy, its pathophysiology, effects on placenta and neonates, maternal and perinatal features and outcomes, the role of vaccination, available treatment options, and the guidelines to be followed during the pandemic are discussed based on the available scientific evidence.

Intention to Receive COVID-19 Vaccine during Pregnancy: A Systematic Review and Meta-analysis

OBJECTIVE

This meta-analysis aimed to assess the level of intent to receive coronavirus disease 2019 (COVID-19) vaccination and demographical factors influencing vaccine uptake among pregnant individuals.

STUDY DESIGN

PubMed, Scopus, and archive/pre-print servers were searched up to May 22nd, 2021. Cross sectional surveys reporting the percentage of the pregnant individuals intending to get a COVID-19 vaccine were considered eligible for meta-analysis. This review was registered with PROSPERO (CRD42021254484). The primary outcome was to estimate the prevalence of COVID-19 vaccination intent among pregnant population. The secondary outcome was to evaluate the factors influencing the intention for vaccination.

RESULTS

Twelve studies sourcing data of 16,926 individuals who were identified as pregnant were eligible. The estimated intention for the receipt of COVID-19 vaccine among women who were pregnant was 47% (95% CI: 38-57%), with the lowest prevalence in Africa 19% (95% CI: 17-21%) and the highest in Oceania 48.0% (95% CI: 44.0-51.0%). Uptake of other vaccines (influenza and/or TdaP) during pregnancy was associated with higher rate of intent to receive the COVID-19 vaccine (OR = 3.03; 95% CI: 1.37-6.73; p = 0.006).

CONCLUSION

The intent to receive COVID-19 vaccine is relatively low among women who are pregnant and substantially varies based on the country of residence. In our meta-analysis, intent of women who were pregnant to receive the COVID-19 vaccine was significantly associated with the history of receiving influenza or TdaP vaccine during pregnancy. Given that in every country only a minority of gravidae have received the COVID-19 vaccine, despite known risks of maternal morbidity and mortality with no evidence of risks of vaccination, it highlights the importance of revised approaches at shared decision making and focused public health messaging by national and international advisories.

KEY POINTS

· The estimated global intention for COVID-19 vaccination among pregnant women was 47%.. · The lowest intention was in Africa and the highest in Oceania.. · These findings highlight the importance of public health messaging by by different agencies..

Effectiveness of a Digital Intervention in Increasing Flu Vaccination-Related Risk Appraisal, Intention to Vaccinate and Vaccination Behaviour Among Pregnant Women

Background

Pregnant women are at increased risk of complications from flu, but uptake of flu vaccination is below 75% targets. Evidence suggests that changing illness risk appraisals may increase vaccination behaviour. In 2018–2019, researchers, public health specialists, and pregnant women co-designed a short animation targeting (unhelpful) beliefs underlying pregnant women’s flu risk appraisals aiming to promote vaccination uptake.

Aims

This study aimed to examine effectiveness of a digital intervention (animation) in increasing flu vaccination among pregnant women through changing illness risk appraisals.

Method

A prospective study design was used, involving convenience sampling of unvaccinated pregnant women recruited via a Qualtrics Online Panel. Participants received small payments via the panel for survey completion. Risk appraisals and intention to vaccinate were measured at baseline and immediately after intervention presentation (follow-up one). Six months later, a further survey (follow-up two) was administered measuring vaccination behaviour.

Results

Baseline and first follow-up surveys were completed by 411 participants. Watching the animation led to increased appraisals of likelihood of getting flu while pregnant and severity of flu during pregnancy, and increased intentions to accept flu vaccination during pregnancy. Of the 67 respondents who completed follow-up survey two, 38 reported having the vaccination while pregnant.

Conclusions

This study provides evidence supporting the promise of the intervention. Randomized controlled trials are required to produce definitive efficacy evidence. Should such a study prove intervention effectiveness, it could be readily embedded within existing campaigns at national and local levels by public health organizations.

The Influenza Vaccine May Protect Pregnant and Postpartum Women against Severe COVID-19

The SARS-CoV-2 pandemic has imposed a huge challenge on the antenatal care of pregnant women worldwide, with the maternal mortality rate being raised to alarming levels. While COVID-19 vaccines were developed, some studies highlighted a possible relationship between influenza vaccination and lower odds of COVID-19 infection. As obstetric patients belong to a high-risk group for respiratory diseases, this study evaluated whether influenza vaccination reduces the severity of COVID-19 infection and mortality among pregnant and postpartum women. We conducted a retrospective cohort study on 3370 pregnant and postpartum women from the Brazilian national database, where they were grouped according to their influenza vaccination status before the onset of COVID-19 symptoms. The intensive care unit admission and intubation rates were significantly higher among subjects in the unvaccinated group (p = 0.002 and p < 0.001, respectively). The odds of mortality risk among those who received the vaccine was 0.33, with a 95% confidence interval of 0.23–0.47. The numbers of patients who needed to be vaccinated to avoid a case of intensive care unit admission, intubation, or death due to COVID-19 were 11, 15, and 11, respectively. Influenza vaccines could confer protection against severe COVID-19 infection in pregnant and postpartum women.

Educational Interventions on Pregnancy Vaccinations during Childbirth Classes Improves Vaccine Coverages among Pregnant Women in Palermo's Province

Maternal immunization is considered the best intervention in order to prevent influenza infection of pregnant women and influenza and pertussis infection of newborns. Despite the existing recommendations, vaccination coverage rates in Italy remain very low. Starting from August 2018, maternal immunization against influenza and diphtheria-tetanus-pertussis were strongly recommended by the Italian Ministry of Health. We conducted a cross sectional study to estimate the effectiveness of an educational intervention, conducted during childbirth classes in three general hospitals in the Palermo metropolitan area, Italy, on vaccination adherence during pregnancy. To this end, a questionnaire on knowledge, attitudes, and immunization practices was structured and self-administered to a sample of pregnant women attending childbirth classes. Then, an educational intervention on maternal immunization, followed by a counseling, was conducted by a Public Health medical doctor. After 30 days following the interventions, the adherence to the recommended vaccinations (influenza and pertussis) was evaluated. At the end of the study 326 women were enrolled and 201 responded to the follow-up survey. After the intervention, among the responding pregnant women 47.8% received influenza vaccination (+44.8%), 57.7% diphtheria-tetanus-pertussis vaccination (+50.7%) and 64.2% both the recommended vaccinations (+54.8%). A significant association was found between pregnant women that received at least one vaccination during pregnancy and higher educational level (graduation degree/master’s degree), employment status (employed part/full-time) and influenza vaccination adherence during past seasons (at least one during last five years). The implementation of vaccination educational interventions, including counseling by healthcare professionals (HCPs), on maternal immunization during childbirth courses improved considerably the vaccination adherence during pregnancy.

Associations between gestational age at birth and infection-related hospital admission rates during childhood in England: Population-based record linkage study

BACKGROUND

Children born preterm (<37 completed weeks' gestation) have a higher risk of infection-related morbidity than those born at term. However, few large, population-based studies have investigated the risk of infection in childhood across the full spectrum of gestational age. The objectives of this study were to explore the association between gestational age at birth and infection-related hospital admissions up to the age of 10 years, how infection-related hospital admission rates change throughout childhood, and whether being born small for gestational age (SGA) modifies this relationship.

METHODS AND FINDINGS

Using a population-based, record-linkage cohort study design, birth registrations, birth notifications and hospital admissions were linked using a deterministic algorithm. The study population included all live, singleton births occurring in NHS hospitals in England from January 2005 to December 2006 (n = 1,018,136). The primary outcome was all infection-related inpatient hospital admissions from birth to 10 years of age, death or study end (March 2015). The secondary outcome was the type of infection-related hospital admission, grouped into broad categories. Generalised estimating equations were used to estimate adjusted rate ratios (aRRs) with 95% confidence intervals (CIs) for each gestational age category (<28, 28-29, 30-31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 and 42 weeks) and the models were repeated by age at admission (<1, 1-2, 3-4, 5-6, and 7-10 years). An interaction term was included in the model to test whether SGA status modified the relationship between gestational age and infection-related hospital admissions. Gestational age was strongly associated with rates of infection-related hospital admissions throughout childhood. Whilst the relationship attenuated over time, at 7-10 years of age those born before 40 weeks gestation were still significantly higher in comparison to those born at 40 weeks. Children born <28 weeks had an aRR of 6.53 (5.91-7.22) during infancy, declining to 3.16 (2.50-3.99) at ages 7-10 years, in comparison to those born at 40 weeks; whilst in children born at 38 weeks, the aRRs were 1·24 (1.21-1.27) and 1·18 (1.13-1.23), during infancy and aged 7-10 years, respectively. SGA status modified the effect of gestational age (interaction P<0.0001), with the highest rate among the children born at <28 weeks and SGA. Finally, study findings indicated that the associations with gestational age varied by subgroup of infection. Whilst upper respiratory tract infections were the most common type of infection experienced by children in this cohort, lower respiratory tract infections (LRTIs) (<28 weeks, aRR = 10.61(9.55-11.79)) and invasive bacterial infections (<28 weeks, aRR = 6.02 (4.56-7.95)) were the most strongly associated with gestational age at birth. Of LRTIs experienced, bronchiolitis (<28 weeks, aRR = 11.86 (10.20-13.80)), and pneumonia (<28 weeks, aRR = 9.49 (7.95-11.32)) were the most common causes.

CONCLUSIONS

Gestational age at birth was strongly associated with rates of infection-related hospital admissions during childhood and even children born a few weeks early remained at higher risk at 7-10 years of age. There was variation between clinical subgroups in the strength of relationships with gestational age. Effective infection prevention strategies should include focus on reducing the number and severity of LRTIs during early childhood.

COVID-19 Vaccination in Pregnancy and Lactation: Current Research and Gaps in Understanding

The COVID-19 pandemic has demonstrated the urgent need to develop vaccine strategies optimized for pregnant people and their newborns, as both populations are at risk of developing severe disease. Although not included in COVID-19 vaccine development trials, pregnant people have had access to these vaccines since their initial release in the US and abroad. The rapid development and distribution of novel COVID-19 vaccines to people at risk, including those who are pregnant and lactating, presents an unprecedented opportunity to further our understanding of vaccine-induced immunity in these populations. In this review, we aim to summarize the literature to date on COVID-19 vaccination in pregnancy and lactation and highlight opportunities for investigation that may inform future maternal vaccine development and implementation strategies.