IgG and IgA Antibodies Post SARS-CoV-2 Vaccine in the Breast Milk and Sera of Breastfeeding Women

The COVID-19 pandemic has carried massive global health and economic burden that is currently counteracted by a challenging anti-COVID-19 vaccination campaign. Indeed, mass vaccination against COVID-19 is expected to be the most efficacious intervention to mitigate the pandemic successfully. The primary objective of the present study is to test the presence of neutralizing anti-SARS-CoV-2 antibodies (IgA and IgG) in the breast milk and sera samples from vaccinated women at least 20 days after the complete vaccine cycle. A secondary aim is to compare the IgG antibodies level in maternal serum and breast milk. The third target is to evaluate the presence of the IgG antibodies in breast milk after several weeks from the vaccination. Finally, we collected information on the health status of infants in the days following maternal vaccination. Forty-two mothers were enrolled in the study. Thirty-six received the Pfizer/BioNTech vaccine, four the Astra Zeneca vaccine, one the Moderna vaccine and another woman Astra Zeneca in the first dose and Pfizer/BioNTech in the second dose. All 42 milk samples confirmed the presence of anti-SARS-CoV-2 IgG, and none showed IgA presence. Regarding the matched 42 sera samples, 41 samples detected IgG presence, with one sample testing negative and only one positive for seric IgA. None of the 42 infants had fever or changes in sleep or appetite in the seven days following the maternal vaccination. The level of IgG antibodies in milk was, on average, lower than that in maternal serum. According to our analysis, the absence of IgA could suggest a rapid decrease after vaccination even if frequent breastfeeding could favour its persistence. IgG were present in breast milk even 4 months after the second vaccine dose. Information on the immunological characteristics of breast milk could change mothers’ choices regarding breastfeeding.

Impact of childhood and maternal vaccination against diphtheria, tetanus, and pertussis in Colombia

Background: In Latin America, there are few studies of the impact of vaccination against diphtheria, tetanus, and pertussis. We estimate the impact of infant and maternal vaccination on the incidence of these diseases in Colombia.Design and methods: an interrupted time series study analyzing the incidence before and after of vaccination with DwPT (1975-2018) and with Tdap in pregnant women (2008-2018). A segmented regression model with negative binomial distribution estimated the change in level and trend of the predicted incidence ratio after vaccination in relation to the incidence if vaccination had not been started (IRR), using a Prais Winsten regression.Results: The pertussis IRR decreased immediately after the start of childhood vaccination (0.91, p=0.51), but this was only significant (1.01, p<0.001) along with the trend per year, after the start of maternal vaccination (0.98, p<0.001). In the absence of vaccination, the incidence would not have been reduced. Neonatal tetanus had the highest rate of change with significant reduction -1.69 - CI 95%: -2.91, -0.48). The trend after vaccination was the highest with an annual reduction of 19% (0.81, p=0.001). The change in incidence of diphtheria was significant, although slow (-0.02 - CI 95%: -0.04, -0.004). The sustained effect in the post-vaccination period was smaller (0.95, p=0.79).Conclusions: Childhood and maternal vaccination markedly reduced the incidence of pertussis and neonatal tetanus. It is necessary to maintain optimal vaccination coverage and surveillance, within an integrated elimination plan, which prevents the resurgence of these diseases.

Maternal vaccination with a type-III glycoconjugate protects mouse neonates against Group B Streptococcus intranasal infection

Group B Streptococcus (GBS) is generally an asymptomatic colonizer of human mucosa but it occasionally infects pregnant women and neonates through vertical transmission, causing disease during the first weeks of life with frequent and severe complications. Preclinical studies have shown that maternal vaccination with polysaccharide-based vaccines protects mothers and offspring from GBS mucosal colonization and consecutive infection. In these models, bacteria were inoculated in mouse either intravaginally in the last trimester of pregnancy or systemically in pups. Here, we investigated whether maternal vaccination with glycoconjugate vaccines may also prevent GBS-mediated colonization and disease in neonates using an infection route that more closely mimics inhalation or ingestion of bacteria during human delivery. To address this point, mice aged less than two days were intranasally challenged with epidemiologically relevant GBS strains. Bacteria were found to colonize nose and intestine, reaching in some cases lungs and blood during the first days of life. Bacteria were also found in vagina of a fraction of colonized female mice within the first month of life. GBS-specific IgG induced by maternal vaccination with a glycoconjugate vaccine formulation were found in blood and mucosal tissues of newborns. Finally, when intranasally challenged with GBS serotype III strains, pups delivered by vaccinated mothers were partially protected against mucosal colonization and deeper infection.

COVID-19 mRNA vaccine in pregnancy and newborn passive immunization: a case report

Aim: Evaluating the newborn passive immunization after maternal vaccination against SARS-COV-2. Case presentation: We present the case of a pregnant woman, with no prior history of COVID-19 infection, who got her second dose of mRNA vaccine against SARS-COV-2, 3 days before the start of her spontaneous labor. She was delivered by cesarean section after dynamical dystocia. Placental cord blood was retrieved immediately and sent to evaluate the titers of COVID-19 antibodies. Vaccine-generated antibodies were present in the umbilical cord with IgG spike >100 AU/ml. Conclusion: By reviewing the literature, vaccination seems to give hope about the potential protective effect of the maternal vaccination on her baby. Thus, pregnant women deserve a priority in the COVID-19 vaccination program.

A qualitative study on perspectives of pregnant and postnatal mothers on accessing Tetanus Toxoid vaccine in Hai District Kilimanjaro region Tanzania

Background: Antenatal care for pregnant and postnatal mothers is the main entry gate for maternal Tetanus Toxoid (TT) vaccination. In developing countries including Tanzania, pregnant and postnatal mothers especially in rural communities have been experiencing barriers to maternal vaccination. The study aimed to explore perspectives of pregnant and postnatal mothers on accessing TT vaccine in Hai District Kilimanjaro Region Tanzania. Methods: A descriptive qualitative study was conducted during baseline assessment from October 2020 to May 2021, in 10 remote villages. Pregnant and postnatal mothers attending antenatal and postnatal services were selected purposively based on their availability and convenience, A semi-structured interview guide relevant to the study objectives was used to guide the interviews. Focus Group Discussion (FGD) and In-depth interviews (IDIs) were conducted; and thematic analysis was used to obtain themes and subthemes. Results: A total of 15 mothers aged 18 to 40 years participated in the study. Most of the mothers were Christians, married with 1 to 5 children. Majority had completed primary level education engaged in small-scale farming. Main themes were extracted namely: Unreliable vaccine information, Healthcare workers attitude, Overworked with household activities, adherence of appointment dates for vaccination after delivery and role of Traditional medicine during pregnancy. Conclusion: The role of healthcare providers are critical component for the appropriate transfer of vaccine information to the mothers and their spouses during clinic visits, to eliminate vaccine misconceptions hence improving overall tetanus vaccine uptake. Quality of information from reliable sources could be an important factor to upgrade the awareness of pregnant mothers on maternal vaccination.