A milk pool was prepared from equal volumes of 50 different milk samples from the Milk Bank of the Hospital Universitário da Universidade de São Paulo and used as a positive control. Y-27632 ic50 The antibody levels were calculated by the difference between the optical density readings obtained with viral

and control antigens. The final titers were reported as relative titers, in percentages, considering the milk pool as 100%. The milk samples were also tested for their G9P[5]-neutralizing ability using MA-104 cell cultures. Equal volumes of milk sample serial dilutions and a suspension containing 100 TCID50/mL of G9P[5] rotavirus were mixed. After 30 minutes of incubation, the mixtures were added to a confluent monolayer of MA-104 cells grown in 96-well microplates. Neutralizing antibody titers were considered as the highest dilution of the samples that showed more than 60% cytopathic effect inhibition after 48 hours of incubation. The correlations between the milk samples SIgA levels and the neutralization titers were calculated using the Spearman correlation coefficient. The confidence interval was set at 95% (95% CI) and p-values < 0.05 were considered to be statistically Navitoclax significant. SIgA anti-rotavirus and neutralization titers,

with maximum and minimum values, 75th and 25th percentiles, mean, and median are presented in Fig. 1. Great individual variations were observed within the SIgA titers obtained by ELISA. The neutralization titers determined by the neutralization assay also varied widely. Depsipeptide mw The highest titer obtained (160) was 16 times greater than the lowest titer (10), and one sample showed a discrepant value. Fig. 2 shows the correlation between SIgA and neutralization titers. One sample showed very high IgA and neutralization titers discrepant from the others. A high significant and positive Spearman correlation coefficient (r = 0.740, p < 0.0001) was observed in the statistical analysis comparing the two parameters. The levels of protection induced by currently

available anti-rotavirus vaccines appear to vary depending on the locality where they have been administered. The protection conferred by vaccination diminished significantly in many countries in Africa and Asia compared to more developed nations, such as Finland.13 However, the factors that influence the low immunogenicity of these vaccines are not yet clear. One possible explanation could be the presence of anti-rotavirus antibodies in the milk of nursing mothers in developing countries where breast-feeding is a more common practice. Due the presence of these antibodies, if the infants are nursed within short periods of time either before or after oral vaccination, the immunological benefits could be compromised.