Fig. 3

Anti-S. aureus-specific IgA and IgG antibodies in milk from immunized and non-immunized cows (OD values). After 4 weeks following nasal immunization (10 weeks after day 0 of pre-immunization = day 0 of pre-infusion), cows were tested for anti-S. aureus-specific IgA and IgG antibodies in milk of immunized and non-immunized cows (a) OD values of anti-S. aureus-specific IgA antibodies in milk after nasal immunization with FKSA or no immunization. b Anti-S. aureus-specific IgG antibodies. Each data point represents the OD value for one composite milk sample (three cows, n = 3), and the bar represents the mean. Black circles correspond to nasal immunization samples, white circles to non-immunization controls. *Significant difference between the mean of each group (P < 0.05)