Impaired innate mucosal immunity in aged mice permits prolonged Streptococcus pneumoniae colonization.

Streptococcus pneumoniae is a frequent asymptomatic colonizer of the nasopharyngeal niche and only occasionally progresses toward infection. The burden of pneumococcal disease is particularly high in the elderly, and the mechanisms behind this increased susceptibility are poorly understood. Here we used a mouse model of pneumococcal carriage to study immunosenescence in the upper respiratory tract (URT).

Salivary immune responses to the 7-valent pneumococcal conjugate vaccine in the first 2 years of life.

Background: The CRM197-conjugated 7-valent pneumococcal vaccine (PCV7) is protective against vaccine serotype disease and nasopharyngeal carriage. Data on PCV7-induced mucosal antibodies in relation to systemic or natural anticapsular antibodies are scarce.

Methods: In a randomized controlled setting, children received PCV7 at age 2 and 4 months (2-dose group), at age 2, 4 and 11 months (2+1-dose group) or no PCV7 (control group).