Infants have persistent anti-SARS-CoV-2 antibody 3 months after maternal COVID vaccination

Recent articles published in the journal Clinical infections We evaluated the kinetics of the anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody from the infant’s mother in relation to the timing of prenatal SARS-CoV-2 vaccination.

study: Dynamics of maternal anti-SARS-CoV-2 antibodies in infants associated with prenatal vaccination timing.. Image Credit: Kateryna Kon / Shutterstock

Background

Pregnant women with SARS-CoV-2 infection are known to be at increased risk for severe coronavirus infection 19 (COVID-19). The Centers for Disease Control and Prevention (CDC) has recorded more than 190,000 cases of SARS-CoV-2 infection in pregnant women since January 2020, with more than 250 COVID-19-related deaths. In addition, COVID-19 during pregnancy is associated with an increased risk of adverse maternal and perinatal consequences.

Previous studies have shown that SARS-CoV-2 vaccination is efficient in pregnancy situations and has a good safety profile. In addition to its important role in reducing maternal illness, prenatal COVID-19 vaccination may immunize newborns in the early sensitive stages of life. However, compared to older children, SARS-CoV-2 infection in early infancy can lead to severe COVID-19.

The authors of this study have previously shown that prenatal COVID-19 vaccination results in effective transplacental transfer of maternally produced anti-SARS-CoV-2 antibodies. To understand the function of these passively acquired antibodies in maintaining newborn immunity and developing prophylactic interventions, it is necessary to determine their persistence.

Shook et al. The anti-SARS-CoV-2 spike (S) antibody was found to remain in newborns between 20 and 32 weeks gestation after maternal vaccination. Neutralizing antibodyOn the other hand, no tests were performed and women vaccinated late or early in gestational age were excluded. In addition, it is unclear whether breastfeeding affects systemic levels of SARS-CoV-2 immunoglobulin G (IgG) antibody.

About research

Given its high clinical relevance, in the current prospective longitudinal study, researchers found that during COVID-19 vaccination of mothers at various stages of pregnancy and early in the infant, anti-SARS-CoV-2 throughout the infant. The purpose was to evaluate the dynamics of Japanese and S antibodies. Postpartum stage. The team investigated how long the maternal stem anti-SARS-CoV-2 antibodies persisted in infants and how they correlated with prenatal vaccination timing.

The study was conducted from February to November 2021 at the Hadasa Medical Center, a university hospital in Jerusalem, Israel. -Prenatal vaccination schemes and multiple pregnancies were excluded from the study. The included women completed the two-dose COVID-19 vaccination regimen within the recommended time frame, namely 3-4 weeks and more than 2 weeks before delivery.

All mothers were screened and confirmed to be nucleocapsid IgG negative. None of the included women had known immunodeficiency or received immunosuppressive therapy. Clinical and demographic data were obtained at the time of enrollment.

The team was also fully breast-fed, having their mother not vaccinated with SARS-CoV-2 during pregnancy and completing a two-dose COVID-19 BNT162b2 vaccination course within the first month of childbirth. Included an additional control cohort of 3 month old infants.

After prenatal BNT162b2 immunization, serum was positively collected from a mother-infant pair at birth and 3 months after birth. Researchers evaluated the IgG titer and neutralizing ability specific for the SARS-CoV-2 receptor binding domain (RBD).

result

The findings show that the study included 56 mother-infant pairs. Moreover, 15 women, or 26.8%, were vaccinated during the first trimester, 16 or 28.6% during the second trimester, and 25, or 44.6%, during the third trimester. Vaccinated.

Anti-SARS-CoV-2-RBD selective IgG was identified in all newborns at birth and on average titer It was 4046 AU / mL, and the maximum concentration was detected after vaccination with the third trimester (median 6763 AU / mL). Infants’ anti-RBD-specific IgG levels decreased dramatically 3 months after delivery, with a median titer of 545 AU / mL. The half-life of anti-RBD-specific IgG was 30 days for infants and 66 days for mothers.

All newborns showed measurable neutralizing activity at birth, regardless of gestational age at vaccination. However, the proportion of infants born to mothers vaccinated with the third trimester maintained SARS-CoV-2 neutralizing activity at 3 months of age than infants born to mothers immunized with the second trimester. I was there.

In summary, current findings show that maternal COVID-19 vaccination results in efficient placental transfer of IgG antibodies targeting SARS-CoV-2 and persistence in early birth. These data highlight the significant impact of prenatal SARS-CoV-2 vaccination on protecting both mothers and babies.

Conclusion

Studies show that maternal COVID-19 vaccination results in significant transplacental anti-SARS-CoV-2 antibody transfer, with persistent antibodies found in all 3-month-old infants. The team has a SARS-CoV-2 neutralizing capacity that can be quantified at birth for all newborns, regardless of gestational age at vaccination, after which antibody titers are significantly reduced and expected total. We found that the half-life was just over 4 weeks.

Compared to early gestational age vaccination, prenatal third trimester vaccination was associated with increased persistence of neutralizing function and elevated neutralizing antibody levels in the infant at 3 months. rice field. The observed effect of prenatal vaccination timing on maternal stem antibody kinetics may affect the SARS-CoV-2 vaccination approach.

In addition, scientists pointed out that the relationship between the mechanism that promotes the difference in antibody decay rates between newborns and mothers and gestational age at vaccination is not yet known. Moreover, better knowledge of the unique kinetics of maternally acquired IgG in newborns was needed to signal the development of means to enhance their sustainability.