Antibodies In Milk Research Articles

Comparing Immunity Elicited by Feedback and Titered Viral Inoculation against PEDV in Swine

Porcine Epidemic Diarrhea Virus (PEDV) can infect pigs of any age, but the disease severity varies significantly, particularly affecting neonatal piglets due to their immature immune system. Various vaccination strategies have been questioned for their efficacy, especially since outbreaks have occurred even on vaccinated farms. Recent suggestions indicate that exposure to the virus may enhance the effectiveness of inactivated vaccines, highlighting the potential benefits of using attenuated viruses to generate immunity in sows without prior exposure. This study aimed to evaluate the humoral and cytokine responses in pregnant sows and their piglets after inoculation of affected piglet intestinal contents and a virus isolated. We measured immune parameters such as IL-12, IL-22, IgG, and IgA, as well as neutralizing antibodies in serum, colostrum, and milk. Notably, higher titers of neutralizing antibodies were found in sows immunized with the viral inoculum, while IL-12 and IL-22 levels showed no significant differences. Additionally, we assessed productive parameters like total piglets born, weaning mortality, average birth weight, and stillborn rates. The results indicated that sows treated with affected piglet intestinal contents had higher mortality (48.31%) and stillborn rates (20.96%) compared to those receiving the isolated virus (30.02% and 10.44%, respectively). These findings suggest that using an isolated virus can offer a safe, long-lasting, and specific immune response, underscoring the importance of thorough analysis of both systemic and mucosal immune responses against PEDV.

Antibodies in breast milk: Pro-bodies designed for healthy newborn development.

This manuscript sheds light on the impact of maternal breast milk antibodies on infant health. Milk antibodies prepare and protect the newborn against environmental exposure, guide and regulate the offspring's immune system, and promote transgenerational adaptation of the immune system to its environment. While the transfer of IgG across the placenta ceases at birth, milk antibodies are continuously replenished by the maternal immune system. They reflect the mother's real-time adaptation to the environment to which the infant is exposed. They cover the infant's upper respiratory and digestive mucosa and are perfectly positioned to control responses to environmental antigens and might also reach their circulation. Maternal antibodies in breast milk play a key role in the immune defense of the developing child, with a major impact on infectious disease susceptibility in both HIC and LMIC. They also influence the development of another major health burden in children-allergies. Finally, emerging evidence shows that milk antibodies also actively shape immune development. Much of this is likely to be mediated by their effect on the seeding, composition and function of the microbiota, but not only. Further understanding of the bridge that maternal antibodies provide between the child and its environment should enable the best interventions to promote healthy development.

SARS-CoV-2 infection induces human milk antibodies capable of mediating multiple functional activities

SARS-CoV-2 infection induces human milk antibodies capable of mediating multiple functional activities

Unique Kinetics of the Human Milk Antibody Response to JYNNEOS Vaccine for Prevention of Monkey Pox: A Case Study.

Background: JYNNEOS is a nonreplicating modified vaccinia Ankara vaccine currently licensed to prevent monkeypox infection, and its milk immunogenicity remains unstudied. Objective: Investigate the human milk immunogenicity of the JYNNEOS vaccine in one individual and examine the milk for evidence of vaccine components. Methods: Immunogenicity of milk and plasma samples were tested by Luminex assays against Vaccinia antigens, and vaccine components were tested using PCR and sandwich ELISA. Results: Plasma antibody (Ab) response increased up to 3.7-fold in immunoglobulin G (IgG) titer and 1.4-fold in IgA compared with baseline, confirming vaccine immunogenicity in this participant 2 weeks post dose 2. Specific plasma IgG remained 1.2- to 1.7-fold above baseline 12 weeks post dose 2, while IgA returned to baseline levels. Notably, the milk response exhibited unique kinetics, particularly for IgA. Milk IgA against all three antigens increased 0.9- to 2.2-fold 2 weeks post dose 2, reaching a peak titer increase of 1.1- to 2.7-fold at 12 weeks post dose 2. Secretory (s) Ab levels increased to 1.1- to 2-fold at 2 weeks post dose 2 and reached a peak of 2- to 3.2-fold increase at the 12-week time point. Importantly, IgA and sAb responses in milk exhibited correlation, suggesting most milk IgA was sIgA. Notably, no vaccine components (VACV protein or DNA) were detected in the milk samples. Conclusion: These data suggest that the milk Ab response to this intradermal (ID) VACV-based vaccine is distinct from that observed systemically, indicating a unique mucosal immune response and highlighting its potential to elicit protective long-lasting sIgA. This case report provides strong evidence for inclusion of this vaccine platform in future studies of maternal vaccines aimed to elicit a protective milk Ab response.

Detection of Hypoderma spp. antibodies in bovine milk in some regions of Nineveh governorate, Iraq

Detection of Hypoderma spp. antibodies in bovine milk in some regions of Nineveh governorate, Iraq

A longitudinal study of the dynamics of Mycoplasma bovis antibody status in primiparous cows and bulk tank milk in Swedish dairy herds

Mycoplasma (M.) bovis is an important pathogen causing pneumonia, mastitis, and arthritis in cattle all over the world entailing reduced animal welfare and economic losses. In this longitudinal study, we investigated the presence of M. bovis antibodies in bulk tank milk (BTM) and in milk from primiparous (PP) cows at 4 sampling occasions over 2 years. Herd characteristics associated with a positive antibody test result in PP cows were investigated. The participating dairy herds (n = 149) were situated in southern Sweden, samples were collected and analyzed with ID Screen antibody ELISA. Information on herd characteristics was retrieved from the national Dairy Herd Improvement database. To identify herd characteristics associated with the presence of antibodies in PP cows, mixed linear regression with herd and sample as random factors were used. The apparent herd-level prevalence of M. bovis infection based on antibodies in BTM was 17% but with the addition of PP cows the prevalence increased to 28%. The results showed that larger herds and introduction of cattle was associated with higher antibody levels in PP cows. In conclusion, this study showed a clear difference in the apparent prevalence of M. bovis infection based on antibodies in BTM or in PP cows, the no. of positive herds were almost doubled when including PP cows. This motivates repeated sampling of a few PP cows to find newly infected herds in an early stage. Finally, the results showed that introduction of cattle influences the level of M. bovis antibodies. This is important in the control and prevention of further spread of the infection. It is essential for free herds to know their M. bovis status and antibody testing is highly recommended if introducing cattle.

Evidence of vertical transmission of Senecavirus A in naturally infected sows

Senecavirus A (SVA) is a Picornaviridae RNA virus that causes vesicular disease (VD) and transitory neonatal losses in pigs. The major ways SVA is spread are by oral, nasal, and feces. Vertical transmission of SVA was investigated during a VD epidemic in a farrow-to-finish herd in Brazil. Vesicular lesions were observed on sows before farrowing and on piglets within 24 h of birth. Analyses included RT-qPCR, viral isolation, sequencing, and virus-neutralization assays on serum, vesicular fluid, colostrum, and milk. Five out of ten sows were viremic before farrowing, and 46.7% of tested piglets had high viral loads in the first 24 h after birth. Infectious virus was detected in colostrum and milk from one postnatal sow. Despite high levels of neutralizing antibodies (nAbs) in piglet serum, colostrum, and milk, piglets were not protected from viremia and clinical illness. These findings support the vertical and congenital transmission of SVA.

Detection and Monitoring of Highly Pathogenic Influenza A Virus 2.3.4.4b Outbreak in Dairy Cattle in the United States.

The emergence and spread of highly pathogenic avian influenza virus A subtype H5N1 (HP H5N1-IAV), particularly clade H5N1 2.3.4.4b, pose a severe global health threat, affecting various species, including mammals. Historically, cattle have been considered less susceptible to IAV, but recent outbreaks of H5N1-IAV 2.3.4.4b in dairy farms suggest a shift in host tropism, underscoring the urgency of expanded surveillance and the need for adaptable diagnostic tools in outbreak management. This study investigated the presence of anti-nucleoprotein (NP) antibodies in serum and milk and viral RNA in milk on dairy farms affected by outbreaks in Texas, Kansas, and Michigan using a multi-species IAV ELISA and RT-qPCR. The analysis of ELISA results from a Michigan dairy farm outbreak demonstrated a positive correlation between paired serum and milk sample results, confirming the reliability of both specimen types. Our findings also revealed high diagnostic performance during the convalescent phase (up to 96%), further improving sensitivity through serial sampling. Additionally, the evaluation of diagnostic specificity using serum and milk samples from IAV-free farms showed an excellent performance (99.6%). This study underscores the efficacy of the IAV NP-blocking ELISA for detecting and monitoring H5N1-IAV 2.3.4.4b circulation in dairy farms, whose recent emergence raises significant animal welfare and zoonotic concerns, necessitating expanded surveillance efforts.

Enhanced D614G and Omicron Variants Antibody Persistence in Infants at 2 Months of Age Following Maternal mRNA Booster Vaccination During Pregnancy or Postpartum

Background: Following maternal COVID-19 vaccination, the persistence of antibodies in sera and breast milk for mothers and infants is not well characterized. We sought to describe the persistence of antibodies through 2 months after delivery in maternal and infant serum and breast milk following maternal COVID-19 mRNA vaccination and to examine differences by receipt of booster dose during pregnancy or postpartum. Methods: This is a prospective cohort study with enrollment from July 2021 to January 2022 at 9 US academic sites. Pregnant or postpartum participants and their infants were enrolled after COVID-19 mRNA monovalent vaccination during pregnancy (primary 2-dose series) with booster (third dose) vaccination during pregnancy or within 2 months post-partum. SARS-CoV-2–binding and functional antibody responses at delivery and 2 months after delivery in mothers and infants were measured by spike and receptor-binding domain immunoglobulin (Ig) G, pseudovirus and live neutralizing antibody (nAb) titers to ancestral and Omicron BA.1 and BA.5 strains. Breast milk spike and receptor-binding domain IgG and IgA titers were also measured. Results: A total of 237 maternal/infant dyads were included (110 primary series during pregnancy, 99 pregnancy booster and 28 postpartum booster). A pregnancy booster resulted in 2.2-4.7-fold higher IgG and nAb at delivery and 2 months for both mothers and infants compared to the primary series alone (P < 0.001 for all comparisons). While infant IgG and nAb titers decreased by 2 months of age, the proportion of infants with detectable nAb at 2 months was greater in infants of mothers boosted during pregnancy compared with primary series for all variants (D614G: 99% vs. 56%; BA.1: 56% vs. 4% and BA.5: 57% vs. 9%; P < 0.001 for all comparisons). Breast milk spike IgA and IgG were present in 64%-100% and 100% of participants, respectively, and those boosted during pregnancy or postpartum had 3.1-4.6-fold higher levels of breast milk antibodies at 2 months compared to primary series during pregnancy (P < 0.001). Conclusions: mRNA COVID-19 monovalent booster vaccination during pregnancy results in significantly higher maternal and infant serum–binding IgG and nAb titers compared to a primary 2-dose series, including against Omicron variants, through 2 months of age. Breast milk antibodies following maternal vaccination during pregnancy or postpartum may provide additional protection during early infancy.

Effect of dry period immunization of Salmonella Dublin latent carriers with a commercial live culture vaccine on intrauterine transmission based on the presence of precolostral antibodies in offspring

Salmonella Dublin latent carrier cows represent a high risk for infection of newborn calves via intrauterine transmission and shedding of bacteria in feces and colostrum at calving. Vaccination of these latent carrier dams during late gestation boosts immunity against S. Dublin. This could reduce the activation of the dormant bacteria during the periparturient immune dysfunction period, thereby reducing the risk of early-life infection in the offspring. Thus, the objective of this study was to evaluate the extent to which vaccinating S. Dublin latent carrier cows at dry-off with a commercial live culture vaccine reduces bacterial shedding at calving and intrauterine infection to calves. To identify latent carriers, we screened 1,084 cows in 4 Michigan commercial dairy farms with a history of S. Dublin. Cows were defined as latent carriers when they showed 3 consecutive positive milk antibody ELISA tests conducted every 2 mo. Subsequently, 148 latent carriers were randomly allocated to the vaccine or control group. Vaccine cows received a commercial live culture vaccine subcutaneously (SC) at dry-off and a booster 2 weeks later. Control cows received saline SC at the same times. At calving, we collected fecal and colostrum samples from the dam and a pre-colostral serum sample from the calf. Bacterial shedding was evaluated in feces and colostrum both qualitatively and quantitatively through bacterial culture and qPCR, respectively. Intrauterine transmission was defined when a calf was positive for serum antibody ELISA at birth. Vaccination decreased the likelihood of calves being born S. Dublin seropositive (Relative Risk [95%CI]) = 0.19 [0.04 - 0.84]). However, no S. Dublin positive isolates were identified through either bacteriological culture or qPCR in feces or colostrum. Vaccination of S. Dublin latent-carrier cows at dry-off reduced intrauterine transmission to calves. Further research is warranted into the potential of vaccination to decrease vertical transmission of S. Dublin in dairy farms. Additionally, the absence of S. Dublin positive fecal and colostrum samples warrants further evaluation of the detection methods for identifying latent carriers or S. Dublin isolation, as well as the role of latent carriers in infecting newborn calves in the maternity area at birth.

Factors Influencing Breast Milk Antibody Titers during the Coronavirus Disease 2019 Pandemic: An Observational Study.

The COVID-19 pandemic has highlighted the role of breastfeeding in providing passive immunity to infants via specific anti-SARS-CoV-2 antibodies in breast milk. We aimed to quantify these antibodies across different lactation stages and identify influencing factors. This prospective study involved mother-child dyads from Innsbruck University Hospital, Austria, with a positive maternal SARS-CoV-2 test during pregnancy or peripartum between 2020 and 2023. We collected breast milk samples at various lactation stages and analyzed anti-Spike S1 receptor-binding domain (S1RBD) immunoglobulins (Ig). Maternal and neonatal data were obtained from interviews and medical records. This study included 140 mothers and 144 neonates. Anti-S1RBD-IgA (72.0%), -IgG (86.0%), and -IgM (41.7%) were highly present in colostrum and decreased as milk matured. Mothers with natural infection and vaccination exhibited higher anti-S1RBD-IgA and -IgG titers in all milk stages. Mothers with moderate to severe infections had higher concentrations of anti-S1RBD-IgA and -IgG in transitional milk and higher anti-S1RBD-IgA and -IgM in mature milk compared to those with mild or asymptomatic infections. Variations in antibody responses were also observed with preterm birth and across different virus waves. This study demonstrates the dynamic nature of breast milk Ig and underscores the importance of breastfeeding during a pandemic.

Development of systemic and mucosal immune responses against gut microbiota in early life and implications for the onset of allergies.

The early microbial colonization of human mucosal surfaces is essential for the development of the host immune system. Already during pregnancy, the unborn child is prepared for the postnatal influx of commensals and pathogens via maternal antibodies, and after birth this protection is continued with antibodies in breast milk. During this critical window of time, which extends from pregnancy to the first year of life, each encounter with a microorganism can influence children's immune response and can have a lifelong impact on their life. For example, there are numerous links between the development of allergies and an altered gut microbiome. However, the exact mechanisms behind microbial influences, also extending to how viruses influence host-microbe interactions, are incompletely understood. In this review, we address the impact of infants' first microbial encounters, how the immune system develops to interact with gut microbiota, and summarize how an altered immune response could be implied in allergies.

Records of antibodies in breast milk in postpartum women who have been vaccinated or exposed to COVID-19: A systematic review

Background: Breast milk is a critical element in developing a baby’s immunity through immune transfer. Antibodies are an essential unit of immunity against infection with the SARS-CoV-2 virus. This paper explores antibodies in breast milk in postpartum women who have been vaccinated or exposed to coronavirus disease 2019 (COVID-19). Duration of antibody appearance was studied to determine the adequate time in transferring antibodies by breastfeeding. Methods: Three databases, PubMed, Google Scholar, and ScienceDirect, were used as sources of articles. Inclusion criteria applied in selecting articles were prospective observational study or experimental design study in English, evaluating antibodies in breast milk, and conducted between 2019–2021. Article quality and risk of bias were assessed with Critical Appraisal Skills Programme (CASP). The data found were synthesized in a narrative manner. Results: This systematic review included 20 articles. A total of 306 postpartum women who were infected with COVID-19, 20 postpartum women who had viral symptoms and 495 postpartum women who had been vaccinated were studied. Immunoglobulin A (IgA) and immunoglobulin G (IgG) antibodies were found in the breast milk of infected and vaccinated postpartum women. SARS CoV-2 infection is associated with the presence of IgA dominant, whereas vaccination is related to the presence of IgG dominant. Antibodies persisted from day 10 of onset to 10 months in infected postpartum women and started from three days to six weeks in vaccinated postpartum women. Meta-analysis could not be carried out due to the variety of articles. Conclusions: Antibodies found in breast milk in infected and vaccinated postpartum women have different dominant types. Further research needs to be done regarding the mechanism of antibody transfer in breast milk, longer research duration and studies that directly examine the comparison of antibodies in breast milk in vaccinated and infected postpartum women. Registration: PROSPERO (CRD42022340859, 23 June 2022).

High Concentrations of Immunoglobulin G Against Cow Milk Proteins and Frequency of Cow Milk Consumption Are Associated With the Development of Islet Autoimmunity and Type 1 Diabetes—The Trial to Reduce Insulin-dependent Diabetes Mellitus (IDDM) in the Genetically at Risk (TRIGR) Study

BackgroundThe Trial to Reduce IDDM in the Genetically at Risk (TRIGR) (NCT00179777) found no difference type 1 diabetes risk between hydrolyzed and regular infant formula. However, cow's milk consumption during childhood is consistently linked to type 1 diabetes risk in prospective cohort studies. ObjectiveOur primary aim was to study whether humoral immune responses to cow’s milk and cow’s milk consumption are associated with type 1 diabetes in TRIGR children. MethodsTRIGR comprised 2159 children with genetic susceptibility to type 1 diabetes born between 2002-2007 in 15 countries. Children were randomized into groups receiving extensively hydrolyzed casein or a regular cow’s milk formula and followed until age 10. Type 1 diabetes related autoantibodies and antibodies to cow’s milk proteins were analyzed. Infant formula intake was measured by structured dietary interviews and milk consumption with a food frequency questionnaire. Associations of milk antibodies and milk consumption with the risk to develop type 1 diabetes were analysed by Cox survival model. ResultsCow’s milk antibody levels both in cord blood [HR for islet autoimmunity 1.30 (95% CI 1.05-1.61); type 1 diabetes 1.32 (1.02-1.71)] and longitudinally from birth to 3 years [islet autoimmunity 1.39 (1.07-1.81); type 1 diabetes 1.43 (1.04-1.96)] were associated with increased risk of developing type 1 diabetes. The amount of regular infant formula was associated with a reduced islet autoimmunity risk in the regular infant formula group [0.92 (0.85-0.99)]. Furthermore, frequent liquid milk consumption after infancy was associated with an increased risk of islet autoimmunity or type 1 diabetes. ConclusionsElevated cow's milk antibody levels and high consumption of liquid milk after infancy are related to type 1 diabetes development in children with an increased genetic susceptibility to type 1 diabetes. Enhanced antibody levels to cow’s milk may provide a biomarker of immune system prone to develop islet autoimmunity. Trial registry numberNCT00179777

Human milk antibodies to global pathogens reveal geographic and interindividual variations in IgA and IgG.

BACKGROUNDThe use of high-throughput technologies has enabled rapid advancement in the knowledge of host immune responses to pathogens. Our objective was to compare the repertoire, protection, and maternal factors associated with human milk antibodies to infectious pathogens in different economic and geographic locations.METHODSUsing multipathogen protein microarrays, 878 milk and 94 paired serum samples collected from 695 women in 5 high and low-to-middle income countries (Bangladesh, Finland, Peru, Pakistan, and the United States) were assessed for specific IgA and IgG antibodies to 1,607 proteins from 30 enteric, respiratory, and bloodborne pathogens.RESULTSThe antibody coverage across enteric and respiratory pathogens was highest in Bangladeshi and Pakistani cohorts and lowest in the U.S. and Finland. While some pathogens induced a dominant IgA response (Campylobacter, Klebsiella, Acinetobacter, Cryptosporidium, and pertussis), others elicited both IgA and IgG antibodies in milk and serum, possibly related to the invasiveness of the infection (Shigella, enteropathogenic E. coli "EPEC", Streptococcus pneumoniae, Staphylococcus aureus, and Group B Streptococcus). Besides the differences between economic regions and decreases in concentrations over time, human milk IgA and IgG antibody concentrations were lower in mothers with high BMI and higher parity, respectively. In Bangladeshi infants, a higher specific IgA concentration in human milk was associated with delayed time to rotavirus infection, implying protective properties of antirotavirus antibodies, whereas a higher IgA antibody concentration was associated with greater incidence of Campylobacter infection.CONCLUSIONThis comprehensive assessment of human milk antibody profiles may be used to guide the development of passive protection strategies against infant morbidity and mortality.FUNDINGBill and Melinda Gates Foundation grant OPP1172222 (to KMJ); Bill and Melinda Gates Foundation grant OPP1066764 funded the MDIG trial (to DER); University of Rochester CTSI and Environmental Health Sciences Center funded the Rochester Lifestyle study (to RJL); and R01 AI043596 funded PROVIDE (to WAP).

Persistence and Efficacy of Maternal COVID-19 Vaccine-Induced Antibodies in Human Milk: A Comprehensive Meta-Analysis

Abstract Background: The ongoing global health challenge posed by the COVID-19 pandemic has necessitated a thorough examination of vaccine efficacy, particularly the transfer of vaccine-induced immunity to infants via human milk. This meta-analysis aims to explore the persistence and efficacy of COVID-19 vaccine-induced antibodies in human milk, offering insights into passive immunity transfer to breastfeeding infants. Methods: We conducted a systematic review and meta-analysis of peer-reviewed studies published from January 2021 to December 2023, extracted from databases such as PubMed, Scopus, and Web of Science. Our focus was on studies measuring SARS-CoV-2-specific antibodies (IgA and IgG) in human milk following maternal COVID-19 vaccination. Results: Fifteen studies involving 1,200 lactating mothers who received mRNA COVID-19 vaccines were included. The analysis highlighted a consistent presence of SARS-CoV-2-specific IgA and IgG antibodies in human milk, persisting for up to six months post-vaccination. Conclusion: The results highlight the noteworthy transmission of COVID-19 antibodies via human milk, suggesting an extended duration of possible protection for neonates against SARS-CoV-2 infection. This argues in favor of immunizing nursing mothers as a preemptive public health strategy to provide their children passive immunity.

SARS-CoV-2 Antibodies in Human Milk After mRNA and Adenovector-Based Vaccination: A Systematic Review and Meta-Analysis.

SARS-CoV-2 specific antibodies exist in human milk expressed by lactating parents after vaccination. In the existing research, the effects of vaccine types on human milk are inconsistent. This study aims to perform a systematic review and meta-analysis of the existing observational studies to compare the positive rates of SARS-CoV-2 specific antibodies in human milk according to mRNA and adenovector-based vaccination. PubMed, Web of Science, Elsevier Science Direct and Cochrane Library databases were systematically searched for relevant articles published from December 30, 2019 to February 15, 2023. Observational studies were considered eligible provided they reported data on SARS-CoV-2 specific antibodies in human milk. The risk of bias in non-randomized studies of interventions (ROBINS-I) tool, the Newcastle-Ottawa Scale (NOS), and the Agency for Healthcare Research and Quality (AHRQ) were used to assess risk of bias. Seven studies, including 511 lactating participants, were included in this review and meta-analysis. The positive rate of SARS-CoV-2 IgA is higher in mRNA vaccine groups than in adenovector-based vaccine groups (OR = 4.80, 95% CI [3.04, 7.58], p < 0.001). The positive rate of SARS-CoV-2 IgG was higher in mRNA vaccines than in adenovector-based vaccines. Compared to adenovector-based vaccines, mRNA vaccines present a higher positivity rate of IgA and IgG in human milk after vaccination. In other words, mRNA vaccinations may offer breastfed children a higher level of protection than adenovector-based vaccinations. Further high-quality data is still required to substantiate these findings.

Estimation of diagnostic sensitivity and specificity of abattoir registrations and bulk tank milk ELISA as herd-level tests for Fasciola hepatica using Bayesian latent class modelling

The common liver fluke, Fasciola hepatica, is a trematode parasite found worldwide, typically with a focal distribution due to its requirement for suitable climatic and environmental conditions to complete its lifecycle. Bovine fasciolosis causes suboptimal production and economic losses, including liver condemnation at slaughter. The lack of reliable diagnostic methods is a disadvantage to the increasing demand for surveillance and control. The aim of this study was to evaluate the diagnostic accuracy of bulk tank milk (BTM) antibody testing and aggregated abattoir registrations (AAR) of liver fluke as herd-level tests for F. hepatica infection using Bayesian latent class models. Data from the abattoirs in 2019–2021 and BTM, sampled in the winter of 2020/2021, were collected from 437 herds on the southwest coast of Norway. The BTM samples were analysed with the SVANOVIR® F. hepatica-Ab ELISA test, with results given as an optical density ratio (ODR), and later dichotomized using the recommended cut-off value from the test manufacturer (ODR ≥0.3). Based on the BTM ELISA test, 47.8% of the herds tested positive. The AAR test was defined as the herd-level proportion of female slaughtered animals registered with liver fluke infection during the study period. For this test, three cut-offs were used (a proportion of 0.05, 0.1 and 0.2). The herds were split into two subpopulations (“Coastal” and “Inland”), which were expected to differ in true prevalence of F. hepatica infection based on climate-related and geographical factors. The diagnostic accuracies of both tests were estimated using Bayesian latent class models with minimally informative priors. Post-hoc analysis revealed that the maximum sum of sensitivity (Se) and specificity (Sp) of the tests was achieved with a herd-level proportion of ≥0.1 registered with liver fluke as the AAR test. Using this cut-off, the median estimate for the diagnostic accuracy of the BTM ELISA was 90.4% (84.0–96.2 95% Posterior Credible Interval (PCI)) for Se and 95.3% (90.6–100% PCI) for Sp, while the median estimate of Se for AAR was 87.5% (81.4–93.1% PCI) and the median estimate of Sp for AAR was 91.0% (85.2–96.5% PCI). The cut-off evaluation of the SVANOVIR® F. hepatica-Ab ELISA test for BTM confirmed the manufacturer's recommended cut-off of ODR ≥0.3 to denote positive and negative herds. This study suggests that AAR and BTM ELISA test can be used as herd-level tools to monitor liver fluke infection, so that appropriate interventions against infection can be implemented as necessary.

Individual- and Herd-Level Milk ELISA Test Status and Incidence for Paratuberculosis in Hubei Province, China.

Mycobacterium avium subsp. paratuberculosis (MAP) is responsible for the persistent infectious illness known as bovine paratuberculosis, which is one of the most easily overlooked diseases in China amid a lack of epidemiological data. In this study, we evaluated the agreement of milk and blood antibody tests for paratuberculosis and showed an overall agreement of 92.0%, with a 95.0% negative coincidence rate and a 78.6% positive coincidence rate. The milk test was then used to examine the prevalence and incidence of dairy cows in Hubei Province, China. We found that, at the individual level, the highest lacto-prevalence reached up to 22.9%; the farm-level prevalence was as high as 92.3% (12/13) and 84.6% (11/13) in January and April 2018, respectively. The total incidence risk of all farms was 6% per three months. We also found that large-scale farms had a significantly lower prevalence and incidence than small-scale farms. Finally, the correlation between paratuberculosis and milk quality was evaluated, and we confirmed that MAP can significantly alter milk quality and raise somatic cell counts in the milk. This study provides valuable information for assessing the prevalence and incidence risk of paratuberculosis in China. It further provides an essential basis for calling for the prevention and control of paratuberculosis in China.

Persistence of COVID-19 Human Milk Antibodies After Maternal COVID-19 Vaccination: Systematic Review and Meta-Regression Analysis.

The World Health Organization (WHO) declared COVID-19 a pandemic. The Centers for Disease Control and Prevention (CDC), WHO, and American College of Obstetricians and Gynecologists (ACOG) recommend vaccination of pregnant and lactating women, aiming to protect both mothers and their infants through transplacental and human milk antibody transmission. This study aims to assess the quantity of antibodies in human milk and determine the effect of time, vaccine type, and dose on antibody level. Single-arm prospective observational studies reportingthe COVID-19-specific antibody level in human milk after COVID-19 vaccination during pregnancy or lactation were included. PubMed, Scopus, Cochrane, EBSCO, and Web of Science were searched from December 2019 to November22, 2022. Data were extracted in a uniform Google sheet.A total of 2657 studies were identified. After the removal of duplicates and screening, 24 studies were included in the systematic review and meta-regression. Human milk COVID-19-specific antibody levels increased with subsequent vaccine doses, as reflected by a positive relationship for the second (coefficient=0.91, P-value 0.043 for IgA and coefficient=1.77, P-value 0.009 for IgG) and third (coefficient=1.23, P-value 0.0029 for IgA and coefficient=3.73, P-value 0.0068 for IgG)doses. The antibody level exhibited a weak positive relationship with the follow-up time (coefficient=0.13, P-value 0.0029 for IgA and coefficient=0.18, P-value 0.016 for IgG). Only one of the 38 infants showed detectable COVID-19 IgM and IgA antibody levels in their blood. There wasan increase in the neutralizing activity of COVID-19 antibodies in human milk following the COVID-19 vaccination. From the analysis of published data, we found high positive levels of antibodies in human milk that increased with subsequent doses. Additionally, the human milk antibodies exhibit a positive neutralizing effect. Only one infant had detectable COVID-19 IgM+IgA antibodies in the blood. Further research is needed to discuss infant protection through a mother'svaccination.