Evaluation of Mucosal Vaccines against Pneumococcal and Meningococcal Diseases

Pneumonia is an infection that affects respiratory tract and lungs and it ́s globally the largest infectious cause of death with 920,136 deaths in 2015 for children under five years old, representing 15% of all obits in this age. The main infectious agent of pneumonia, the bacterium Streptococcus pneumoniae, is normally found at nose or throat and can spread by droplets from a cough or sneeze [1]. S. pneumoniae is capable to cause serious severe invasive disease, but it can colonize individuals that will not to present symptoms, suggesting that colonization represents the primary selective force for this bacterium [2]. In the same way, meningococcal meningitis is a bacterial lifethreatening disease caused mainly by Neisseria meningitidis. In Europe, the US and other developed countries, meningococcal disease incidence is typically between 1 and 10 per 100,000 population, with occasional ‘hyper endemic’ periods of persistent disease caused by particular strains [3]. A strip of land of SubSaharan Africa, extending from Senegal to Ethiopia is referred as the “African Meningitis Belt”, represents 430 million people at risk in 26 African countries, with recurring epidemics causing 20,000 to 200,000 cases and 2,000 to 20,000 deaths annually [4]. As transmission of these diseases occurs mainly by respiratory tract, including from asymptomatic individuals carriers, mucosal immunization mechanisms must be constantly evaluated.