In China, approximately 30?K children less than 5?years of age die from IPD every year.10 In the US in 2014, the IPD morbidity and mortality rates for older adults aged 65C74?years were 19.1 instances and 2.41 deaths per 100,000 population, respectively, while in those 85?years of age, the rates were 42.6 instances and 8.01 deaths per 100,000 population.11 In developing countries, the incidence rates for IPD are several times higher than they may be in industrialized countries, and existing data probably underestimate the true disease burden because of the insufficient diagnostic capacity and extensive antibiotic use. In addition to affecting young children and older adults, often attacks persons with high-risk conditions: e.g., human being immunodeficiency disease (HIV) infection, pregnant women, and individuals with cancer, influenza and diabetes. conditions. Currently, you will find two licensed pneumococcal vaccines: pneumococcal polysaccharide vaccines (PPVs) and pneumococcal conjugate vaccines (PCVs). The conjugation of pneumococcal polysaccharide to carrier proteins elicits a T-cell dependent immune response, primarily characterized by the differentiation of memory space B cells and improved antibody concentrations.1 With the widely use of these two vaccines, scientists now are considering the combined PCV/PPV regimens, which may open up the possibility of broadening serotype coverage as well as prolonging the duration of vaccine protective effect. The pathogen and epidemiology of pneumococcal disease is definitely a Gram-positive encapsulated diplococcus, and its polysaccharide capsule is an essential virulence factor. At least 94 serologically unique pneumococcal serotypes have been recognized. 2 The distribution of these serotypes varies significantly between countries and populations.3 In Europe, the most frequent serotypes are 1, 3, 7F, 14 and 19A,4,5 while in China, E6130 19F, 23F, 19A, 6B, 14, 6A and 15B are most frequent.6 A worldwide surveillance system undertaken in 2008 showed that the most common serotypes in children were 19A (28%), 19F (10%) and 14 (9%), whereas in adults the most common serotypes were 19A(13%), 3(7%), 6A (7%) and 7F(7%).7 In general, pneumococcal diseases can be classified as either invasive (IPD) or E6130 non-invasive pneumococcal disease. The incidence of IPD is definitely bimodal, with one peak in babies 2?years of age and the other in older adults 65?years of age.8 The World Health Organization (WHO) reported that in 2015, pneumonia (due to all causes, but is the most common cause) killed E6130 920?K children 5?years of age, accounting for 16% of all deaths with this age group.9 Pneumonia mortality was especially severe in South Asia and sub-Saharan Africa. In China, approximately 30?K children under 5?years of age die from IPD every year.10 In the US in 2014, the IPD morbidity and mortality rates for older adults aged 65C74?years were 19.1 instances and 2.41 deaths per 100,000 population, respectively, while in those 85?years of age, the rates were 42.6 instances and 8.01 deaths per 100,000 population.11 In developing countries, the incidence rates for IPD are several times higher than they may be in industrialized countries, and existing data probably underestimate the true disease burden because of the insufficient diagnostic capacity and extensive antibiotic use. In addition to affecting young children and older adults, often attacks individuals with high-risk conditions: e.g., human being immunodeficiency disease (HIV) infection, pregnant women, and individuals with malignancy, influenza and diabetes. For example, individuals with E6130 diabetes may have three- to six-fold improved risk of IPD compared with healthy individuals.12 For many T persons who also are immunocompromised, the risks are even greater. The development of pneumococcal polysaccharide vaccines was first isolated in the US and France in 1880.13,14 In 1911, the first pneumococcal whole-cell vaccine was tested among young platinum miners in South Africa, but despite early statements that it was protective, careful analysis showed it was not efficacious.14 Later, in 1930, Tillet and Francis discovered that purified pneumococcal polysaccharides could induce specific anti-capsular antibodies in humans. In 1945, Macleod, Heidelberger and colleagues showed that a 4-valent pneumococcal polysaccharide vaccine (PPV4) comprising serotypes 1, 2, 5 and 7 was protecting against pneumococcal disease caused by the same serotypes.15 Much later in 1968, 6-valent and 13-valent.