COVID-19 and novel mRNA vaccines in pregnancy: an updated literature review

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.

Pregnancy and SARS-CoV-2 infection with a focus on its vertical transmission, breastfeeding, cord blood banking, and vaccination during COVID-19 infection

The SARS-CoV-2 outbreak led to a health crisis worldwide. This infection can infect individuals, particularly pregnant women. In this review, we tried to find the possibility of vertical transmission of COVID-19 and investigate the effects of COVID-19 on pregnancy, breastfeeding, cord blood banking, and the effects of recommended vaccines on pregnant and lactating women. Keywords include COVID-19, congenital infection, SARS-CoV-2, pregnancy, and COVID-19 vaccines. Vertical transmission of SARS-CoV-2 was searched in scientific databases, such as PubMed, Google Scholar, and Scopus. The criteria for including studies in this article are the study of SARS-CoV-2 infection in pregnant women, fetuses, and neonates during pregnancy and while breastfeeding, and also the effect of COVID-19 vaccines on them. There are several conflicting results in the transmission of SARS-CoV-2 from the maternal-fetal interface. Since many neonates born from COVID-19-infected mothers had no signs of this infection, the possibility of SARS-CoV-2 congenital transmission cannot be confirmed. Also, SARS-CoV-2-infected women can breastfeed their babies if they have mild symptoms. Up till now, no adverse effect of COVID-19 vaccines has been identified on mothers, infants, and the fertility of men or women. Even so, more investigations are needed on the long-term effects of COVID-19 vaccines.

Evaluation of non-clinical toxicity studies of COVID-19 vaccines

In this study we evaluated the outcomes of non-clinical toxicity studies of various SARS-CoV-2 vaccines produced with different manufacturing technologies, with focus on Repeated Dose Toxicity (RDT) and Developmental and Reproductive Toxicity (DART) studies. We found that RDT and DART studies at doses relevant for human treatment showed no adverse effects while remaining observations were expected findings including local reactogenicity, immune response and macroscopic findings at the injection site. We have also reviewed the European Medicines Agency (EMA) nonclinical assessment reports for market authorization. Regardless of utilized vaccine manufacturing technology EMA assessment of the non-clinical studies consisted most frequently of comments related to study design, species selection and missing data. Sponsors have often submitted platform studies (vaccine studies with the same technology/construct but using other antigens) as supplementary data. Animal model-based toxicity testing has shown rather small effects, which have been never serious adverse effects. The translational value to support clinical development is mainly to inflammatory effects, indicative of the primary action of the vaccines. From a 3R perspective supportive platform technology data consisting of previously executed RDT and DART studies from the same platform technology are encouraged to be implemented in the vaccine assessment process.

Maternal and perinatal outcomes of COVID-19 vaccination during pregnancy

Objective

To investigate maternal adverse effects and perinatal and neonatal outcomes of women receiving coronavirus disease-2019 (COVID-19) vaccination during pregnancy.

Material and Methods

Seven hundred and sixty pregnant women who were followed up in obstetrics outpatients were included in this prospective cohort study. COVID-19 vaccination and infection histories of the patients were recorded. Demographic data, including age, parity, and presence of systemic disease and adverse events following COVID-19 vaccination were recorded. Vaccinated pregnant women were compared with unvaccinated women in terms of adverse perinatal and neonatal outcomes.

Results

Among the 760 pregnant women who met study criteria, the data of 425 pregnant women were analyzed. Among these, 55 (13%) were unvaccinated, 134 (31%) were vaccinated before pregnancy, and 236 (56%) pregnant women were vaccinated during pregnancy. Of those who were vaccinated, 307 patients (83%) received BioNTech, 52 patients (14%) received CoronaVac, and 11 patients (3%) received both CoronaVac and BioNTech. The local and systemic adverse effect profiles of patients who received COVID-19 vaccination either before or during pregnancy were similar (p=0.159), and the most common adverse effect was injection site pain. COVID-19 vaccination during pregnancy did not increase the ratio of abortion (<14 wk), stillbirth (>24 wk), preeclampsia, gestational diabetes mellitus, fetal growth restriction, second-trimester soft marker incidence, time of delivery, birth weight, preterm birth (<37 wk) or admission to the neonatal intensive care unit compared to the women who were not vaccinated during pregnacy.

Conclusion

COVID-19 vaccination during pregnancy did not increase maternal local and systemic adverse effects or poor perinatal and neonatal outcomes. Therefore, regarding the increased risk of morbidity and mortality related to COVID-19 in pregnant women, the authors propose that COVID-19 vaccination should be offered to all pregnant women.

An Update on COVID-19 Vaccination and Pregnancy

Pregnant women are more prone to experience severe COVID-19 disease, including intensive care unit (ICU) admission, use of invasive ventilation, extracorporeal membrane oxygenation (ECMO), and mortality compared to non-pregnant individuals. Additionally, research suggests that SARS-CoV-2 infection during pregnancy is linked to adverse pregnancy outcomes, such as preterm birth, preeclampsia, and stillbirth, as well as adverse neonatal outcomes, including hospitalization and admission to the neonatal intensive care unit. This review assessed the available literature from November 2021 to 19 March 2023, concerning the safety and effectiveness of COVID-19 vaccination during pregnancy. COVID-19 vaccination administered during pregnancy is not linked to significant adverse events related to the vaccine or negative obstetric, fetal, or neonatal outcomes. Moreover, the vaccine has the same effectiveness in preventing severe COVID-19 disease in pregnant individuals as in the general population. Additionally, COVID-19 vaccination is the safest and most effective method for pregnant women to protect themselves and their newborns from severe COVID-19 disease, hospitalization, and ICU admission. Thus, vaccination should be recommended for pregnant patients. While the immunogenicity of vaccination in pregnancy appears to be similar to that in the general population, more research is needed to determine the optimal timing of vaccination during pregnancy for the benefit of the neonate.

Inflammatory and Immune Responses during SARS-CoV-2 Infection in Vaccinated and Non-Vaccinated Pregnant Women and Their Newborns

BACKGROUND

Pregnant women are more susceptible to severe disease associated with SARS-CoV-2 infection. We performed a prospective study to analyze the inflammatory and immune profile after SARS-CoV-2 infection occurring in vaccinated or non-vaccinated pregnant women and their newborns.

METHODS

Twenty-five pregnant women with SARS-CoV-2 infection were enrolled, and sixteen cord blood samples were obtained at delivery.

RESULTS

We observed that IL-1β, TNF-α, Eotaxin, MIB-1β, VEGF, IL-15, IL-2, IL-5, IL-9, IL-10 and IL-1ra levels were significantly higher in vaccinated than non-vaccinated mothers. Furthermore, the newborns of the vaccinated mothers produced higher levels of IL-7, IL-5 and IL-12 compared to the newborns of non-vaccinated mothers. Anti-Spike (S) IgG levels were significantly higher in all vaccinated mothers and their newborns compared to the non-vaccinated group. We found that 87.5% of vaccinated women and 66.6% of non-vaccinated women mounted an S-specific T-cell response quantified by ELISpot assay. Moreover, 75.0% of vaccinated mothers and 38.4% of non-vaccinated mothers showed S-specific CD4⁺ T-cell proliferative response. The T-helper subset response was restricted to CD4⁺ T_h1 in both vaccinated and non-vaccinated women.

CONCLUSION

A higher level of cytokines, IgG antibodies and memory T cells was noted in the vaccinated women. Furthermore, the maternal IgG antibody trans-placental transfer occurred more frequently in vaccinated mothers and may protect the newborn.

Severity of SARS-CoV-2 infection in pregnant women and their neonates during the Omicron period compared to the pre-Omicron period: A retrospective cohort study

AIM

To compare the clinical outcomes among women diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy, and their neonates, during the period when the Omicron variant predominated in Japan with those of the pre-Omicron variant period.

METHODS

We conducted a retrospective single-center cohort study between August 1, 2020, and June 30, 2022. The cohort was divided into pre-Omicron group (August 1, 2020 to November 30, 2021) and Omicron group (December 1, 2021 to June 30, 2022). The primary outcome was maternal intensive care unit (ICU) admission during the perinatal period. The secondary outcomes were maternal oxygen administration before and after delivery, preterm birth (PTB), and low birth weight (LBW).

RESULTS

During the study period, 81 pregnant women were admitted to the hospital with SARS-CoV-2 infection (pre-Omicron period, n = 28; Omicron period, n = 53). SARS-CoV-2 infection during the Omicron period was associated with lower risk of maternal ICU admission (adjusted-odds ratio [aOR]: 0.10, 95% confidence interval [CI]: 0.01-1.23, p = 0.072), oxygen administration via a nasal cannula or mask (aOR: 0.18, 95% CI: 0.03-0.96, p = 0.045), PTB (aOR: 0.15, 95% CI: 0.04-0.51, p = 0.002), and LBW (aOR: 0.13, 95% CI: 0.03-0.55, p = 0.005).

CONCLUSION

Among pregnant women, SARS-CoV-2 infection during the Omicron period was associated with reduced risk of maternal ICU admission, requiring supplemental oxygen, PTB, and LBW. This can be attributable to lower virulence of the Omicron variant and higher vaccination coverage during the Omicron period.

COVID-19 in Pregnant Women, Maternal-Fetal Involvement, and Vertical Mother-to-Child Transmission: A Systematic Review

Pregnant women are included in the COVID-19 risk groups even if they do not have any pathology. This requires an analysis of research focused on pregnant women to understand the impact of SARS-CoV-2 on their condition. There is also a need to know whether there is vertical mother-to-child transmission, as well as other consequences in case the pregnant woman is infected and COVID-19 positive. A systematic review was carried out to analyze the existing information on the complications of a pregnant woman infected with the SARS-CoV-2 coronavirus and the possibility of vertical transmission from mother to child, registered in the PROSPERO website and searched in the PubMed, Scopus, CINAHL, and Cochrane Library databases. Finally, 22 articles were included in the review. The review suggests that vertical transmission from mother to child could be exceptionally possible at the time of delivery or breastfeeding, but not through the placenta. It is interesting to point out the good acceptance of vaccination by pregnant women, which may be the reason for the low infectivity. Further research on pregnant women should be carried out to provide evidence on vertical mother-to-child transmission and the role of breast milk in relation to SARS-CoV-2.

Association of initial COVID-19 vaccine hesitancy with subsequent vaccination among pregnant and postpartum individuals

Objective

To examine the association between initial COVID‐19 vaccine hesitancy and subsequent vaccination among pregnant and postpartum individuals.

Design

Prospective cohort.

Setting

A Midwestern tertiary‐care academic medical center. Individuals completed a baseline vaccine hesitancy assessment from 22 March 2021 to 2 April 2021, with subsequent ascertainment of vaccination status at 3–6 months follow‐up.

Methods

We used multivariable Poisson regression to estimate the relative risk of vaccination by baseline vaccine hesitancy status, and then characteristics associated with vaccination.

Main outcome measures

Self‐report of COVID‐19 vaccination, and secondarily, consideration of COVID‐19 vaccination among those not vaccinated.

Results

Of 456 individuals (93% pregnant, 7% postpartum) initially surveyed, 290 individuals (64%; 23% pregnant, 77% postpartum) provided subsequent vaccination status (median = 17 weeks). Of these 290 individuals, 40% (116/290) reported COVID‐19 vaccine hesitancy upon enrolment, of whom 52% reported subsequent vaccination at follow‐up. Few individuals transitioned during the study period from vaccine hesitant to vaccinated (10%); in comparison, 80% of those who were not vaccine hesitant were vaccinated at follow‐up (aRR 0.19, 95% CI 0.11–0.33). Among those who remained unvaccinated at follow‐up, 38% who were vaccine hesitant at baseline were considering vaccination, compared with 71% who were not vaccine hesitant (aRR 0.48, 95% CI 0.33–0.67). Individuals who were older, parous, employed and of higher educational attainment were more likely to be vaccinated, and those who identified as non‐Hispanic black, were Medicaid beneficiaries, and were still pregnant at follow‐up were less likely to be vaccinated.

Conclusions

COVID‐19 vaccine hesitancy persisted over time in the peripartum period, and few individuals who reported hesitancy at baseline were later vaccinated. Interventions that address vaccine hesitancy in pregnancy are needed.

COVID‐19 vaccination hesitancy among pregnant and postpartum individuals persists over time, and few of the individuals who reported hesitancy were later vaccinated.

Overview of Neural Tube Defects: Gene–Environment Interactions, Preventative Approaches and Future Perspectives

Neural tube defects (NTDs) are the second most common congenital malformations of humans, characterized by impaired development of the central nervous system. Even though the etiology of most birth defects remains undetermined, genetic and environmental risk factors in the background of NTDs have been identified and extensively reported. On top of genetic and nutritional risks which include mutations in both coding and non-coding regions and maternal folate status, respectively, recent years have seen a rise in the identification of a variety of teratogens that could be implicated in NTD development. These include polycyclic aromatic hydrocarbons, arsenic, pesticides, maternal hyperthermia and antibiotics as well as pain and seizure medication. With an increase in understanding of teratogens leading to NTD formation, preventative and treatment approaches have witnessed great advances throughout the years. While the most common preventative approach includes folic acid food fortification as well as suggested inositol supplementation, treatment and management approaches differ greatly depending on the developmental stage and the site of the lesion and include prenatal surgery, stem cell transplantation and postnatal surgery. Because NTDs still represent a large health and financial burden for the patient and society as a whole, it is crucial to investigate potential risk factors and develop novel approaches in order to fully prevent this category of disorders.

Management of pregnant women with COVID-19: A tertiary pandemic center experience on 1416 cases

The aim of this study is to share the comprehensive experience of a tertiary pandemic center on pregnant women with COVID-19 and to compare clinical outcomes between pregnancy trimesters. The present prospective cohort study consisted of pregnant women with COVID-19 who were followed up at Ankara City Hospital between March 11, 2020 and February 20, 2021. Clinical characteristics and perinatal outcomes were compared between the pregnancy trimesters. A total of 1416 pregnant women (1400 singletons and 16 twins) with COVID-19 were evaluated. Twenty-six (1.8%) patients were admitted to the intensive care unit (ICU) and maternal mortality was observed in six (0.4%) cases. Pregnancy complications were present in 227 (16.1%) cases and preterm labor was the most common one (n = 42, 2.9%). There were 311, 433, and 672 patients in the first, second, and third trimesters of pregnancy, respectively. Rates of mild and severe/critic COVID-19 were highest in the first and second trimesters, respectively. The hospitalization rate was highest in the third trimester. Pregnancy complications, maternal mortality, and NICU admission rates were similar between the groups. The course of the disease and obstetric outcomes may be different among pregnancy trimesters. A worse course of the disease may be observed even in pregnant women without any coexisting health problems.