Impact of maternal SARS-CoV-2 booster vaccination on blood and breastmilk antibodies.

Maternal COVID-19 vaccination could protect infants who are ineligible for vaccine through antibody transfer during pregnancy and lactation. We measured the quantity and durability of SARS-CoV-2 antibodies in human milk and infant blood before and after maternal booster vaccination. Prospective cohort of lactating women immunized with primary and booster COVID-19 vaccines during pregnancy or lactation and their infants. Milk and blood samples from October 2021 to April 2022 were included. Anti-nucleoprotein (NP) and anti-receptor binding domain (RBD) IgG and IgA in maternal milk and maternal and infant blood were measured and compared longitudinally after maternal booster vaccine. Forty-five lactating women and their infants provided samples. 58% of women were anti-NP negative and 42% were positive on their first blood sample prior to booster vaccine. Anti-RBD IgG and IgA in milk remained significantly increased through 120-170 days after booster vaccine and did not differ by maternal NP status. Anti-RBD IgG and IgA did not increase in infant blood after maternal booster. Of infants born to women vaccinated in pregnancy, 74% still had positive serum anti-RBD IgG measured on average 5 months after delivery. Infant to maternal IgG ratio was highest for infants exposed to maternal primary vaccine during the second trimester compared to third trimester (0.85 versus 0.29; p<0.001). Maternal COVID-19 primary and booster vaccine resulted in robust and long-lasting transplacental and milk antibodies. These antibodies may provide important protection against SARS-CoV-2 during the first six months of life.

Vaccination Beliefs and Attitudes of Lactating People During the SARS-CoV-2 Pandemic.

BACKGROUND: Pregnant and recently pregnant people have lower vaccination rates against SARS-CoV-2 than the general population, despite increased risk of adverse outcomes from infection. Little is known about vaccine hesitancy in this population. RESEARCH AIM: To characterize SARS-CoV-2 and other vaccine attitudes of lactating people who accepted the SARS-CoV-2 vaccine, describing their vaccine experiences to further contextualize their beliefs. METHODS: A prospective cross-sectional online survey design was used. We administered the survey to 100 lactating people in Pennsylvania from April to August 2021, upon enrollment into a longitudinal study investigating SARS-CoV-2 vaccine antibodies in human milk. This survey assessed SARS-CoV-2 vaccine attitudes, vaccine counseling from providers, and vaccine decision making. Associations between vaccination timing and beliefs were analyzed by Pearson chi-square. RESULTS: Of 100 respondents, all received ≥ 1 SARS-CoV-2 vaccine before or shortly after enrollment, with 44% (n = 44) vaccinated in pregnancy and 56% (n = 56) while lactating. Participants reported vaccination counseling by obstetric (n = 48; 70%) and pediatric (n = 25; 36%) providers. Thirty-two percent (n = 32) received no advice on SARS-CoV-2 vaccination from healthcare providers, while 69% (n = 69) were counseled that vaccination was safe and beneficial.While 6% (n = 6) and 5% (n = 5) reported concerns about the safety of maternal vaccines for lactating people or their infants, respectively, 12% (n = 12) and 9% (n = 9) expressed concerns about the safety of maternal SARS-CoV-2 vaccination in particular. CONCLUSIONS: Despite high uptake of SARS-CoV-2 vaccine among participants, safety concerns persisted, with many reporting a lack of direct counseling from providers. Future research should investigate how variability in provider counseling affects SARS-CoV-2 vaccine uptake in perinatal populations.

Monoclonal Antibodies for Treatment of SARS-CoV-2 Infection During Pregnancy : A Cohort Study.

BACKGROUND: Monoclonal antibody (mAb) treatment decreases hospitalization and death in high-risk outpatients with mild to moderate COVID-19. However, no studies have evaluated adverse events and effectiveness of mAbs in pregnant persons compared with no mAb treatment. OBJECTIVE: To determine the frequency of drug-related adverse events and obstetric-associated safety outcomes after treatment with mAb compared with no mAb treatment of pregnant persons, and the association between mAb treatment and a composite of 28-day COVID-19-related hospital admission or emergency department (ED) visit, COVID-19-associated delivery, or mortality. DESIGN: Retrospective, propensity score-matched, cohort study. SETTING: UPMC Health System from 30 April 2021 to 21 January 2022. PARTICIPANTS: Persons aged 12 years or older with a pregnancy episode and any documented positive SARS-CoV-2 test (polymerase chain reaction or antigen test). INTERVENTION: Bamlanivimab and etesevimab, casirivimab and imdevimab, or sotrovimab treatment compared with no mAb treatment. MEASUREMENTS: Drug-related adverse events, obstetric-associated safety outcomes among persons who delivered, and a risk-adjusted composite of 28-day COVID-19-related hospital admission or ED visit, COVID-19-associated delivery, or mortality. RESULTS: Among 944 pregnant persons (median age [interquartile range (IQR)], 30 years [26 to 33 years]; White (79.5%; n = 750); median Charlson Comorbidity Index score [IQR], 0 [0 to 0]), 552 received mAb treatment (58%). Median gestational age at COVID-19 diagnosis or treatment was 179 days (IQR, 123 to 227), and most persons received sotrovimab (69%; n = 382). Of those with known vaccination status, 392 (62%) were fully vaccinated. Drug-related adverse events were uncommon (n = 8; 1.4%), and there were no differences in any obstetric-associated outcome among 778 persons who delivered. In the total population, the risk ratio for mAb treatment of the composite 28-day COVID-19-associated outcome was 0.71 (95% CI, 0.37 to 1.4). The propensity score-matched risk ratio was 0.61 (95% CI, 0.34 to 1.1). There were no deaths among mAb-treated patients compared with 1 death in the nontreated control patients. There were more non-COVID-19-related hospital admissions in the mAb-treated persons in the unmatched cohort (14 [2.5%] vs. 2 [0.5%]; risk ratio, 5.0; 95% CI, 1.1 to 21.7); however, there was no difference in the propensity score-matched rates, which were 2.5% mAb-treated vs. 2% untreated (risk ratio, 1.3; 95% CI, 0.58% to 2.8%). LIMITATIONS: Drug-related adverse events were patient and provider reported and potentially underrepresented. Symptom severity at the time of SARS-CoV-2 testing was not available for nontreated patients. CONCLUSION: In pregnant persons with mild to moderate COVID-19, adverse events after mAb treatment were mild and rare. There was no difference in obstetric-associated safety outcomes between mAb treatment and no treatment among persons who delivered. There was no difference in 28-day COVID-19-associated outcomes and non-COVID-19-related hospital admissions for mAb treatment compared with no mAb treatment in a propensity score-matched cohort. PRIMARY FUNDING SOURCE: No funding was received for this study.