Minimal mRNA uptake and inflammatory response to COVID-19 mRNA vaccine exposure in human placental explants

Despite universal recommendations for COVID-19 mRNA vaccination in pregnancy, uptake has been lower than desired. There have been limited studies of the direct impact of COVID-19 mRNA vaccine exposure in human placental tissue. Using a primary human placental explants model, we investigated the uptake of two common mRNA vaccines (BNT162b2 Pfizer-BioNTech or mRNA-1273 Moderna), and whether exposure altered villous cytokine responses. Explants derived from second or third trimester chorionic villi were incubated with vaccines at supraphysiologic concentrations and analyzed at two time points. We observed minimal uptake of mRNA vaccines in placental explants by in situ hybridization and quantitative RT-PCR. No specific or global cytokine response was elicited by either of the mRNA vaccines in multiplexed immunoassays. Our results suggest that the human placenta does not readily absorb the COVID-19 mRNA vaccines nor generate a significant inflammatory response after exposure.

Assessment of Adverse Reactions, Antibody Patterns, and 12-month Outcomes in the Mother-Infant Dyad After COVID-19 mRNA Vaccination in Pregnancy

Importance

Longitudinal data on COVID-19 messenger RNA (mRNA) vaccine reactogenicity and immunogenicity in pregnancy and for the mother-infant dyad are needed.

Objective

To examine COVID-19 mRNA vaccine reactogenicity and immunogenicity in pregnancy and observe longitudinal maternal and infant outcomes.

Design, Setting, and Participants

This prospective cohort study of pregnant individuals enrolled in the COVID-19 Vaccination in Pregnancy and Lactation study from December 1, 2020, through December 31, 2021, with follow-up through March 31, 2022, was conducted at a large academic medical center in an urban metropolitan area in California. Pregnant individuals receiving COVID-19 mRNA vaccines (mRNA-1273 [Moderna] and BNT162b2 [Pfizer-BioNTech]) were eligible. Of 81 participants enrolled, 5 were excluded after enrollment: 1 terminated pregnancy, 1 received the third vaccine dose prior to delivery, and 3 delivered prior to completing the initial vaccine series.

Exposure

COVID-19 mRNA vaccination at any time during pregnancy.

Main Outcomes and Measures

The primary outcomes were vaccine response as measured by blood Immunoglobulin G (IgG) titers after each vaccine dose and self-reported postvaccination symptoms. Patients' IgG titers were measured in cord blood and in infant blood at intervals up to 1 year of life; IgG and IgA titers were measured in maternal milk. Clinical outcomes were collected from medical records.

Results

Of 76 pregnant individuals included in final analyses (median [IQR] maternal age, 35 [29-41] years; 51 [67.1%] White; 28 [36.8%] primigravid; 37 [48.7%] nulliparous), 42 (55.3%) received BNT162b2 and 34 (44.7%) received mRNA-1237. There were no significant differences in maternal characteristics between the 2 vaccine groups. Systemic symptoms were more common after receipt of the second vaccine dose than after the first dose (42 of 59 [71.2%] vs 26 of 59 [44.1%]; P = .007) and after mRNA-1237 than after BNT162b2 (25 of 27 [92.6%] vs 17 of 32 53.1%; P = .001). Systemic symptoms were associated with 65.6% higher median IgG titers than no symptoms after the second vaccine dose (median [IQR], 2596 [1840-4455] vs 1568 [1114-4518] RFU; P = .007); mean cord titers in individuals with local or systemic symptoms were 6.3-fold higher than in individuals without symptoms. Vaccination in all trimesters elicited a robust maternal IgG response. The IgG transfer ratio was highest among individuals vaccinated in the second trimester. Anti-SARS-CoV-2 IgG was detectable in cord blood regardless of vaccination trimester. In milk, IgG and IgA titers remained above the positive cutoff for at least 5-6 months after birth, and infants of mothers vaccinated in the second and third trimesters had positive IgG titers for at least 5 to 6 months of life. There were no vaccine-attributable adverse perinatal outcomes.

Conclusions and Relevance

The findings of this cohort study suggest that mRNA COVID-19 vaccination in pregnancy provokes a robust IgG response for the mother-infant dyad for approximately 6 months after birth. Postvaccination symptoms may indicate a more robust immune response, without adverse maternal, fetal, or neonatal outcomes.

Neutralizing antibody activity against SARS-CoV-2 variants in gestational age-matched mother-infant dyads after infection or vaccination

Pregnancy confers unique immune responses to infection and vaccination across gestation. To date, there are limited data comparing vaccine- and infection-induced neutralizing Abs (nAbs) against COVID-19 variants in mothers during pregnancy. We analyzed paired maternal and cord plasma samples from 60 pregnant individuals. Thirty women vaccinated with mRNA vaccines (from December 2020 through August 2021) were matched with 30 naturally infected women (from March 2020 through January 2021) by gestational age of exposure. Neutralization activity against the 5 SARS-CoV-2 spike sequences was measured by a SARS-CoV-2-pseudotyped spike virion assay. Effective nAbs against SARS-CoV-2 were present in maternal and cord plasma after both infection and vaccination. Compared with WT spike protein, these nAbs were less effective against the Delta and Mu spike variants. Vaccination during the third trimester induced higher cord-nAb levels at delivery than did infection during the third trimester. In contrast, vaccine-induced nAb levels were lower at the time of delivery compared with infection during the first trimester. The transfer ratio (cord nAb level divided by maternal nAb level) was greatest in mothers vaccinated in the second trimester. SARS-CoV-2 vaccination or infection in pregnancy elicits effective nAbs with differing neutralization kinetics that are influenced by gestational time of exposure.

Evaluation of transplacental transfer of mRNA vaccine products and functional antibodies during pregnancy and early infancy

Studies are needed to evaluate the safety and effectiveness of mRNA SARS-CoV-2 vaccination during pregnancy, and the levels of protection provided to their newborns through placental transfer of antibodies. We evaluated the transplacental transfer of mRNA vaccine products and functional anti-SARS-CoV-2 antibodies during pregnancy and early infancy in a cohort of 20 individuals vaccinated during pregnancy. We found no evidence of mRNA vaccine products in maternal blood, placenta tissue, or cord blood at delivery. However, we found time-dependent efficient transfer of IgG and neutralizing antibodies to the neonate that persisted during early infancy. Additionally, using phage immunoprecipitation sequencing, we found a vaccine-specific signature of SARS-CoV-2 Spike protein epitope binding that is transplacentally transferred during pregnancy. In conclusion, products of mRNA vaccines are not transferred to the fetus during pregnancy, however timing of vaccination during pregnancy is critical to ensure transplacental transfer of protective antibodies during early infancy.

Evaluation of transplacental transfer of mRNA vaccine products and functional antibodies during pregnancy and early infancy

Studies are needed to evaluate the safety and effectiveness of mRNA SARS-CoV-2 vaccination during pregnancy, and the levels of protection provided to their newborns through placental transfer of antibodies. We evaluated the transplacental transfer of mRNA vaccine products and functional anti-SARS-CoV-2 antibodies during pregnancy and early infancy in a cohort of 20 individuals vaccinated during pregnancy. We found no evidence of mRNA vaccine products in maternal blood, placenta tissue, or cord blood at delivery. However, we found time-dependent efficient transfer of IgG and neutralizing antibodies to the neonate that persisted during early infancy. Additionally, using phage immunoprecipitation sequencing, we found a vaccine-specific signature of SARS-CoV-2 Spike protein epitope binding that is transplacentally transferred during pregnancy. In conclusion, products of mRNA vaccines are not transferred to the fetus during pregnancy, however timing of vaccination during pregnancy is critical to ensure transplacental transfer of protective antibodies during early infancy.

COVID-19 mRNA Vaccination in Lactation: Assessment of Adverse Events and Vaccine Related Antibodies in Mother-Infant Dyads

Background

Data regarding symptoms in the lactating mother-infant dyad and their immune response to COVID-19 mRNA vaccination during lactation are needed to inform vaccination guidelines.

Methods

From a prospective cohort of 50 lactating individuals who received mRNA-based vaccines for COVID-19 (mRNA-1273 and BNT162b2), blood and milk samples were collected prior to first vaccination dose, immediately prior to 2nd dose, and 4-10 weeks after 2nd dose. Symptoms in mother and infant were assessed by detailed questionnaires. Anti-SARS-CoV-2 antibody levels in blood and milk were measured by Pylon 3D automated immunoassay and ELISA. In addition, vaccine-related PEGylated proteins in milk were measured by ELISA. Blood samples were collected from a subset of infants whose mothers received the vaccine during lactation (4-15 weeks after mothers' 2nd dose).

Results

No severe maternal or infant adverse events were reported in this cohort. Two mothers and two infants were diagnosed with COVID-19 during the study period before achieving full immune response. PEGylated proteins were not found at significant levels in milk after vaccination. After vaccination, levels of anti-SARS-CoV-2 IgG and IgM significantly increased in maternal plasma and there was significant transfer of anti-SARS-CoV-2-Receptor Binding Domain (anti-RBD) IgA and IgG antibodies to milk. Milk IgA levels after the 2nd dose were negatively associated with infant age. Anti-SARS-CoV-2 IgG antibodies were not detected in the plasma of infants whose mothers were vaccinated during lactation.

Conclusions

COVID-19 mRNA vaccines generate robust immune responses in plasma and milk of lactating individuals without severe adverse events reported.

COVID-19 mRNA Vaccination in Lactation: Assessment of adverse events and vaccine related antibodies in mother-infant dyads

BACKGROUND

Data regarding adverse events observed in the lactating mother-infant dyad and their immune response to COVID-19 mRNA vaccination during lactation are needed to inform vaccination guidelines.

METHODS

From a prospective cohort of 50 lactating individuals who received mRNA-based vaccines for COVID-19 (mRNA-1273 and BNT162b2), blood and milk samples were collected prior to first vaccination dose, immediately prior to 2nd dose, and 4-10 weeks after 2nd dose. Symptoms in mother and infant were assessed by detailed questionnaires. Anti-SARS-CoV-2 antibody levels in blood and milk were measured by Pylon 3D automated immunoassay and ELISA. In addition, vaccine-related PEGylated proteins in milk were measured by ELISA. Blood samples were collected from a subset of infants whose mothers received the vaccine during lactation (4-15 weeks after mothers' 2nd dose).

RESULTS

No severe maternal or infant adverse events were reported in this cohort. Two mothers and two infants were diagnosed with COVID-19 during the study period. PEGylated proteins, were not found at significant levels in milk after vaccination. After vaccination, levels of anti-SARS-CoV-2 IgG and IgM significantly increased in maternal plasma and there was significant transfer of anti-SARS-CoV-2-Receptor Binding Domain (anti-RBD) IgA and IgG antibodies to milk. Milk IgA levels after the 2nd dose were negatively associated with infant age. Anti-SARS-CoV-2 IgG antibodies were not detected in the plasma of infants whose mothers were vaccinated during lactation.

CONCLUSIONS

COVID-19 mRNA vaccines generate robust immune responses in plasma and milk of lactating individuals without severe adverse events reported.

Passive and active immunity in infants born to mothers with SARS-CoV-2 infection during pregnancy: prospective cohort study

OBJECTIVE

To investigate maternal immunoglobulins' (IgM, IgG) response to SARS-CoV-2 infection during pregnancy and IgG transplacental transfer, to characterise neonatal antibody response to SARS-CoV-2 infection, and to longitudinally follow actively and passively acquired antibodies in infants.

DESIGN

A prospective observational study.

SETTING

Public healthcare system in Santa Clara County (California, USA).

PARTICIPANTS

Women with symptomatic or asymptomatic SARS-CoV-2 infection during pregnancy and their infants were enrolled between 15 April 2020 and 31 March 2021.

OUTCOMES

SARS-CoV-2 serology analyses in the cord and maternal blood at delivery and longitudinally in infant blood between birth and 28 weeks of life.

RESULTS

Of 145 mothers who tested positive for SARS-CoV-2 during pregnancy, 86 had symptomatic infections: 78 with mild-moderate symptoms, and 8 with severe-critical symptoms. The seropositivity rates of the mothers at delivery was 65% (95% CI 0.56% to 0.73%) and the cord blood was 58% (95% CI 0.49% to 0.66%). IgG levels significantly correlated between the maternal and cord blood (Rs=0.93, p<0.0001). IgG transplacental transfer ratio was significantly higher when the first maternal positive PCR was 60-180 days before delivery compared with <60 days (1.2 vs 0.6, p<0.0001). Infant IgG seroreversion rates over follow-up periods of 1-4, 5-12, and 13-28 weeks were 8% (4 of 48), 12% (3 of 25), and 38% (5 of 13), respectively. The IgG seropositivity in the infants was positively related to IgG levels in the cord blood and persisted up to 6 months of age. Two newborns showed seroconversion at 2 weeks of age with high levels of IgM and IgG, including one premature infant with confirmed intrapartum infection.

CONCLUSIONS

Maternal SARS-CoV-2 IgG is efficiently transferred across the placenta when infections occur more than 2 months before delivery. Maternally derived passive immunity may persist in infants up to 6 months of life. Neonates are capable of mounting a strong antibody response to perinatal SARS-CoV-2 infection.

Passive and active immunity in infants born to mothers with SARS-CoV-2 infection during pregnancy: Prospective cohort study

OBJECTIVE

To investigate maternal immunoglobulins' (IgM, IgG) response to SARS-CoV-2 infection during pregnancy and IgG transplacental transfer, to characterize neonatal antibody response to SARS-CoV-2 infection, and to longitudinally follow actively- and passively-acquired SARS-CoV-2 antibodies in infants.

DESIGN

A prospective observational study.

SETTING

A public healthcare system in Santa Clara County (CA, USA).

PARTICIPANTS

Women with SARS-CoV-2 infection during pregnancy and their infants were enrolled between April 15, 2020 and March 31, 2021.

OUTCOMES

SARS-CoV-2 serology analyses in the cord and maternal blood at delivery and longitudinally in infant blood between birth and 28 weeks of life.

RESULTS

Of 145 mothers who tested positive for SARS-CoV-2 during pregnancy, 86 had symptomatic infections: 78 with mild-moderate symptoms, and eight with severe-critical symptoms. Of the 147 newborns, two infants showed seroconversion at two weeks of age with high levels of IgM and IgG, including one premature infant with confirmed intrapartum infection. The seropositivity rates of the mothers at delivery was 65% (95% CI 0.56-0.73) and the cord blood was 58% (95% CI 0.49-0.66). IgG levels significantly correlated between the maternal and cord blood (Rs= 0.93, p< 0.0001). IgG transplacental transfer ratio was significantly higher when the first maternal positive PCR was 60-180 days before delivery compared to <60 days (1.2 vs. 0.6, p=<0.0001). Infant IgG negative conversion rate over follow-up periods of 1-4, 5-12, and 13-28 weeks were 8% (4/48), 12% (3/25), and 38% (5/13), respectively. The IgG seropositivity in the infants was positively related to IgG levels in the cord blood and persisted up to six months of age.

CONCLUSIONS

Maternal SARS-CoV-2 IgG is efficiently transferred across the placenta when infections occur more than two months before delivery. Maternally-derived passive immunity may protect infants up to six months of life. Neonates mount a strong antibody response to perinatal SARS-CoV-2 infection.

Abstract P1-10-15: Pentoxifylline and vitamin E therapy compliance in patients with breast fibrosis following adjuvant radiotherapy

Purpose: Radiation therapy is an important treatment modality in the curative management of early stage breast cancer. With increasing cancer survivorship, late effects of cancer treatment have become increasingly relevant. Breast fibrosis is a common late effect following therapeutic irradiation which can potentially result in pain, poor cosmesis, and functional impairment. Randomized trials have suggested that radiation fibrosis may be reversible or preventable using a medication regimen of Pentoxifylline and Vitamin E. These clinical trials have shown excellent patient compliance and tolerability of this regimen, but it is unclear if this tolerability translates to clinical practice. The goal of this study is to investigate the clinical tolerability and compliance with pentoxifylline and Vitamin E therapy in patients with radiation induced breast fibrosis while determining possible correlates to discontinuation.

Methods: We identified ninety patients who were prescribed Pentoxifylline (400mg three time daily) and Vitamin E (400 IU once daily) following definitive breast radiation therapy from January 2013 to December 2015. A retrospective cohort study was conducted utilizing medical record analysis. Data was collected including patient age, comorbid conditions, concurrent medications, duration of pentoxifylline and Vitamin E therapy, any dose adjustments, patient reported side effects, and any reported reason for discontinuation. Multivariate analysis of correlation between medication compliance and these categorical variables was assessed with Chi squared (χ2) analysis of independence.

Results: Raw patient compliance with Pentoxifylline and Vitamin E therapy was found to be poor with 33 of 87 (38%) of patients requiring either dose reduction or discontinuation of therapy due to side effects. The majority of patient complaints leading to dose adjustments were GI related with nausea (n=20) abdominal pain (n=4), and diarrhea (n=1) reported. There was a statistically significant relationship between concurrent antiemetic therapy and successful completion of pentoxifylline regimen. Patients completed therapy at a rate of 76% with concurrent antiemetic vs 48% without (p=0.007). There was a statistically significant relationship between concurrent proton pump inhibitor therapy and discontinuation of pentoxifylline. Patients completed pentoxifylline therapy at a rate of 33% with concurrent proton pump inhibitor vs 81% without (p=&lt;0.001). Treatment compliance was not significantly correlated with age, pre-existing GERD, time since completing radiation therapy, concurrent use of aromatase inhibitor, tamoxifen, vitamin E, or chemotherapy.

Conclusion: Patient compliance with Pentoxifylline and Vitamin E for radiation induced breast fibrosis appears to be worse in clinical practice compared with previously reported randomized trials. Nausea was the most commonly reported side effect resulting in discontinuation of the regimen. Our data suggests concurrent antiemetic therapy is correlated with strong regimen compliance while concurrent proton pump inhibitor therapy is correlated with poor compliance independent of comorbid conditions. These data should be discussed with patients prior to initiation of treatment.

Citation Format: Famoso JM, Gonzalez VJ, McBride A. Pentoxifylline and vitamin E therapy compliance in patients with breast fibrosis following adjuvant radiotherapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-10-15.

Abstract P3-12-12: Incidence of internal mammary node, sternum, and manubrium failure as detected by FDG-18 PET/CT

Introduction:

Elective radiotherapy to the internal mammary (IM) lymph nodes remains an ongoing subject of debate. While the incidence of occult IM involvement on extended mastectomy ranges from 15-65%, reported rates of IM failure are substantially lower (approximately 1%). Interest in this subject has resurfaced recently as randomized trials have shown a survival benefit to adjuvant regional node irradiation including the IM chain. The mechanism by which extended field radiotherapy leads to improved systemic outcomes has not been clearly demonstrated and the degree of benefit directly attributable to IM irradiation remains to be seen. We hypothesized that the IM lymphatic chain may provide a direct route for tumor cell dissemination into the the sternum or manubrium. As such, sternal metastases may be a manifestation of IM involvement rather than true hematogenous metastases. We sought to better elucidate patterns of failure by evaluating the incidence and timing of IM, sternal, or manubrial involvement identified by PET/CT imaging following diagnosis of metastatic breast cancer.

Patients and Methods:

Between 2007 and 2014, 96 patients with invasive breast cancer were found to have metastatic disease as diagnosed on FDG-18 PET/CT. Site of recurrence was scored as breast/chest wall, axilla/supraclav, IM chain, sternum/manubrium, or distant. IM or sternum/manubrium failure was scored as isolated (occurring without distant metastatic disease), synchronous (involved at initial diagnosis of distant metastatic disease), or metachronous (involved at any time after diagnosis of metastatic disease).

Results:

Isolated IM failures were observed in 3.1% of patients while isolated sternum/manubrium failures were recorded in 7.3% of patients. Isolated involvement of the sternum/manubrium or IM nodes occurred in 11.4%. The rate of synchronous IM failure was 11.4% with the rate of metachronous failure being 13.5%. The rate of synchronous sternum/manubrium failure was 17.7% with the rate of metachronous failure being 23.9%. The incidence of sternum/manubrium or IM involvement at the initial diagnosis of distant metastatic disease was 29.2% with the rate of involvement at any point increasing to 36.5%.

Conclusion:

The rate of internal mammary node failure by PET/CT at the time of metastatic diagnosis is higher than the incidence reported in previous trials. This discrepancy is likely due increased sensitivity of PET/CT and the difficulty of accurately assessing this region once patients have been found to have metastatic disease. Interestingly, sternum and manubrium were more often the first site of recurrence than the IM nodes. This could be due to a tropism of hematogenous metastases for these bones or could represent direct tumor cell dissemination from the internal mammary chain. This is of special interest as this region is incidentally included in the radiotherapy fields when targeting the IM nodes. Overall, our findings suggest that historic patterns of failure studies may underestimate the local benefit of internal mammary node radiotherapy.

Citation Format: Grow JL, Choudhary G, Kuo P, Livingston RB, Gonzalez VJ. Incidence of internal mammary node, sternum, and manubrium failure as detected by FDG-18 PET/CT. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-12-12.

Abstract P1-12-03: Primary squamous cell carcinoma of the breast

BACKGROUND: Primary squamous cell carcinoma of the breast (PSCCB) is one of the rarest forms of breast cancer, accounting for less than 0.1% of all breast cancers. PSCCB can be aggressive with no typical radiologic findings on mammogram, often leading to delays in diagnoses or missed diagnoses. Previously reported cases of PSCCB have illustrated a wide range of clinical presentations, from an abnormal mammogram with no obvious breast mass to a breast abscess. In addition, due to the rarity of this disease, no clear consensus on definitive treatment or prognosis exists.

METHODS: Using a search of our pathology database, we identified females diagnosed with PSCCB at our institution from 2007-2012. Inclusion criteria included female patients over the age of 18 years old with a primary tumor consisting of &gt;90% malignant cells of squamous origin. Likewise, exclusion criteria included squamous cell cancer that had metastasized to the breast from elsewhere or lesions that were not independent of the overlying skin or nipple. We then performed a retrospective review to evaluate patient characteristics, presentation, tumor characteristics, treatment modalities and outcomes.

RESULTS: We identified three patients who were diagnosed with PSCCB during that timeframe. Their ages ranged from 35-65 years old, with two being post-menopausal and one pre-menopausal. Of the three, two were Caucasian and one was Hispanic. All three presented after self-palpating a breast mass. The average size of the mass seen on mammogram was 2.9 cm (range of 2.4 to 3.6 cm). Histologically, all three of the cancers were moderately to poorly differentiated. In addition, they all had a negative estrogen, progesterone, and HER2 receptor status with an elevated Ki-67. One patient was diagnosed at our institution but did not proceed to surgery and was lost to follow up. For the other two patients, one chose to undergo breast conservation with partial mastectomy and sentinel lymph node biopsy followed by whole breast radiation. The second patient proceeded with a total mastectomy and sentinel lymph node biopsy without radiation. There was no evidence of regional nodal disease in either patient at time of surgery. Furthermore, neither patient received any systemic therapy. Both patients were disease free at last follow up which was 5 and 11 months respectively.

CONCLUSION: Because PSCCB is so rare, prognosis and optimal treatment are still controversial. Most of the current literature portrays PSCCB as an aggressive cancer with a poor prognosis. This often leads to multimodality therapy consisting of mastectomy with axillary nodal clearance, adjuvant chemotherapy and radiation. In addition, locoregional and distant recurrences are common despite this aggressive treatment leading to the conclusion that PSCCB is relatively radioresistant with limited activity seen when using conventional breast cancer systemic therapies. Because treatment options can be limited, more research is needed to further elucidate the biological behavior of this rare cancer as well prognostic factors that may allow us to treat a patient more conservatively.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-12-03.