ABSTRACT
Meningococcal conjugate vaccines induce serum antibodies crucial for protection against invasive disease. Salivary antibodies are believed to be important for hindering meningococcal acquisition and/or clearance of established carriage. In this study, we measured salivary IgA and IgG antibodies induced by vaccination with a monovalent serogroup A conjugate vaccine or a tetravalent A, C, W and Y conjugate vaccine, in comparison with antibody levels in serum. Saliva and serum samples from Ethiopian volunteers (1-29 years) collected before and eight times on a weekly basis after receiving the serogroup A conjugate vaccine, the tetravalent serogroup A, C, W and Y conjugate vaccine, or no vaccine (control group), were analysed using a multiplex microsphere immunoassay for antibody detection. Serogroup-specific IgG antibody levels in saliva increased significantly after vaccination with both vaccines. The monovalent serogroup A vaccine also induced an increase in salivary IgA antibodies. A strong correlation between serogroup-specific IgG antibodies in saliva and serum, and a somewhat lower correlation for IgA, was observed for all serogroups. There was also a strong correlation between specific secretory IgA and IgA antibodies in saliva for all serogroups. Meningococcal conjugate vaccines are able to elicit salivary antibodies against serogroup A, C, W and Y correlating with antibody levels in serum. The strong correlation between saliva and serum antibody levels indicates that saliva may be used as a surrogate of systemic antibody responses.
Subject(s)
Antibodies, Bacterial/metabolism , Blood Proteins/metabolism , Meningitis, Meningococcal/prevention & control , Neisseria meningitidis/immunology , Saliva/metabolism , Vaccines, Conjugate/immunology , Adolescent , Adult , Antibody Formation , Child , Child, Preschool , Ethiopia , Female , Humans , Immunoglobulin A/blood , Infant , Male , Meningitis, Meningococcal/immunology , Serogroup , Vaccination , Volunteers , Young AdultABSTRACT
In the absence of an affordable conjugate meningococcal vaccine, mass vaccination campaigns with polysaccharide vaccines are the means to control meningitis epidemics in sub-Saharan Africa. Facing global vaccine shortage, the use of reduced doses, which have been shown to be protective by serum bactericidal activity, can save many lives. In this study, we investigated the antibody responses and avidity of IgG antibodies evoked against the serogroup A capsule of Neisseria meningitidis by different doses of an A/C/Y/W135 polysaccharide vaccine. Volunteers in Uganda were vaccinated with 1/10, 1/5 or a full dose (50 µg) and revaccinated with a full dose after 1 year. Specific IgG geometric mean concentrations and geometric mean avidity indices (GMAI) were determined by a modified enzyme-linked immunosorbent assay (ELISA) using thiocyanate as a chaotropic agent. After vaccination with 1/10 or 1/5 doses, the GMAI increased from 1 month to 1 year. One year following the initial dose, the GMAI levels were higher in the arm receiving reduced doses than for the arm receiving a full dose. Following the second full dose, avidity indices equalized at approximately the same level in the three arms. Although there are practical challenges to the use of reduced doses in the field, our findings suggest that reduced doses of polysaccharide vaccine are able to elicit antibodies of as good avidity against serogroup A polysaccharide as a full dose.
Subject(s)
Antibodies, Bacterial/immunology , Antibody Affinity , Immunoglobulin G/immunology , Meningococcal Vaccines/immunology , Neisseria meningitidis, Serogroup A/immunology , Adolescent , Child , Child, Preschool , Humans , Meningococcal Vaccines/administration & dosage , Randomized Controlled Trials as Topic , Uganda , Vaccination , Young AdultABSTRACT
Coronary artery bypass surgery has gained a major role in the management of ischemic heart disease. Relief of symptoms is often the primary goal for these surgical procedures while other effects relating to rehabilitation of such patients have been neglected. To determine change in work status as a result of operation, job status and hours worked before and after surgery were analyzed in 350 patients who had coronary artery bypass grafting procedures. Overall, there was no improvement in return to work or hours worked after surgery. Hours worked before surgery, relief of symptoms, severity of disease, number of bypass grafts placed, and level of education all related substantially to a change in work capacity. It appears that if the potential for enhanced productivity is to be realized, rehabilitative measures must be intensified following coronary artery surgery.
