Maternal transfer of IgA and IgG SARS-CoV-2 specific antibodies transplacentally and via breast milk feeding.

Background: Although there have been many studies on antibody responses to SARS-CoV-2 in breast milk, very few have looked at the fate of these in the infant, and whether they are delivered to immunologically relevant sites in infants.

Methods: Mother/infant pairs (mothers who breast milk fed and who were SARS-CoV-2 vaccinated before or after delivery) were recruited for this cross-sectional study. Mother blood, mother breast milk, infant blood, infant nasal specimen, and infant stool was tested for IgA and IgG antibodies against SARS-CoV-2 spike trimer.

Mucosal and Systemic Responses to Severe Acute Respiratory Syndrome Coronavirus 2 Vaccination Determined by Severity of Primary Infection.

With much of the world infected with or vaccinated against severe acute respiratory syndrome coronavirus 2 (commonly abbreviated SARS-CoV-2; abbreviated here SARS2), understanding the immune responses to the SARS2 spike (S) protein in different situations is crucial to controlling the pandemic. We studied the clinical, systemic, mucosal, and cellular responses to two doses of SARS2 mRNA vaccines in 62 individuals with and without prior SARS2 infection that were divided into three groups based on antibody serostatus prior to vaccination and/or degree of disease symptoms among those with prior SARS2 infection: antibody negative (naive), low symptomatic, and symptomatic. Antibody negative were subjects who were antibody negative (i.

Nucleotide Substitutions in Hepatitis B Viruses Derived from Chronic HBV Patients.

Background: Mutations in the S gene (HBsAg), pre-core (PC), and basic core promoter (BCP) of the hepatitis B virus (HBV) infection are correlated with disease progression. This study assessed the frequency of mutations in the S gene, PC, and BCP regions in chronic hepatitis B (CHB) patients.

Methods: 104 formerly known CHB patients who visited Tehran Hepatitis centers, were included.

Different Genotypes of Adhesion Operon Genes in Staphylococcus epidermidis Isolates From Various Ocular Infections.

Background: Staphylococcus epidermidis is one of the common causes of bacterial keratitis and post-operation infections. One of the most important virulence factors of S. epidermidis is biofilm formation.