Magnitude, Duration, Quality, and Function of Pneumococcal Vaccine Responses in Elderly Adults

Abstract

The suboptimal efficacy of the currently available 23-valent pneumococcal vaccine in the growing population of adults ú65 years old may be related to the limited immunogenicity of the vaccine polysaccharides in this group. In this study, the majority of elderly outpatients with stable chronic illnesses generated a vigorous IgG response to seven vaccine serotypes comparable to that of healthy young adults at 1, 3, and 16 months after immunization. Moreover, the quality and function of anticapsular antibodies, measured as avidity and in vitro opsonization, were comparable between elderly and young subjects over time. However, a subset (Ç20%) of elderly outpatients responded to fewer than two of seven serotypes tested 1 and 3 months after immunization, whereas none of the healthy young adults were such poor responders. Thus, despite the adequate mean immune responses of the elderly as a group, a substantial proportion of elderly persons may have poor responses to the currently available pneumococcal vaccine.Effective prevention of Streptococcus pneumoniae infection control studies. These studies have indicated variable and incomplete protection (60% -81%) from lethal disease among has renewed priority in an era in which the emergence of antibiotic-resistant strains has further compromised efforts to immunized elderly adults [6 -11].The variable efficacy of the pneumococcal vaccine in the reduce early mortality from invasive pneumococcal infection [1 -3]. Although the 23-valent pneumococcal polysaccharide elderly presumably reflects the poor immunogenicity of polysaccharide-based vaccines in this population. Measurements of (PPS) vaccine was formulated to prevent invasive infection in the elderly and other high-risk populations, the protective effi-PPS-specific serum antibodies after pneumococcal immunization of the elderly have produced conflicting results, possibly cacy of this vaccine for the growing population of adults ú65 years old remains uncertain. Doubts regarding the vaccine's because of differences in the selection of subjects (e.g., chronically ill or unusually healthy elderly) or controls (e.g., historical ability to prevent pneumococcal infection in this group were first raised by prospective randomized trials that did not detect controls or cohort) and in methods for assaying antibody concentrations [12 -20]. More importantly, measures of the quality significant reductions in the incidence of pneumococcal bronchitis, pneumonia, or bacteremia in immunized elderly adults of immune responses to pneumococcal vaccine in the elderly have been assayed in only a single report [19], and the func- [4,5]. However, these studies may have lacked sufficient statistical power to exclude the possibility of vaccine efficacy, due tional response to pneumococcal immunization has not been previously assessed. to the unexpectedly low frequency of pneumococcal infection during these trials. Because further clinical trials were not feasiTherefore, in order to establish the effectiveness of pneumococcal vaccination in elderl...

Immunogenicity of a 23-valent pneumococcal polysaccharide vaccine in Brazilian elderly

“…The present study demonstrated that, at 1 month after immunization, the sera of elderly persons had levels of specific capsular antibodies similar to those of healthy younger persons, as reported elsewhere (16,27). For both groups, serotypes 3 and 6B elicited lower increases (<2) and, by this criterion, these antigens appeared to be less immunogenic in both groups (10,26).…”

“…We also observed that serotypes 1, 5, and 8 induced a high level of humoral response for both groups. As also noted by other investigators (15,16), serotype 8 induced the highest fold increase in the young adult subjects. Actu-ally, the concentration of anti-polysaccharide 8 IgG in 89-SF serum had not been assigned at the time of our study, and therefore we performed the cross-standardization method of Conception and Frasch (31).…”

“…Although serotype 8 is less common in Brazil, this antigen was included because, like serotypes 2, 9, and 14, it has reproducible immunogenicity as defined by a two-fold increase in antibody titers obtained for normal controls (15,16). All six serotypes analyzed in the present study are included in the 23-valent vaccine.…”

Meeting the challenge: prevention of pneumococcal disease with conjugate vaccines

“…These same groups are at greater risk of pneumococcal invasion to the bloodstream and central nervous system, and thus, are at greater risk of death. 8,9 The incidence of pneumococcal infection varies geographically, but increasing rates have been observed in many developed and developing countries. In a survey of 560 pneumococcal blood isolates from patients in Southern Sweden between 1981 and 1996, the incidence of pneumococcal bacteremia increased from 5.2 to 15.2/100 000 per year.…”

Desenvolvimento e avaliação da resposta imune humoral de uma vacina anti-pneumocócica conjugada: polissacarídeo capsular sorotipo 14 - proteína de superfície pneumocócica A.

“…Portanto, pode-se inferir que a idade é um importante fator de risco para colonização pneumocócica e que a sua influência varia de acordo com a fase de crescimento ao longo da vida. De forma semelhante, a distribuição dos sorotipos pneumocócicos também pode variar de acordo com a região geográfica, o tempo e a apresentação clínica dos pacientes, onde a população negra, índios americanos e nativos do Alasca, indivíduos tabagistas, alcoolistas ou com condições médicas crônicas como diabetes, doença falciforme, doenças cardíacas, pulmonares e renais, doenças imunossupressoras, particularmente a AIDS, também fazem parte do grupo de risco (BEREZIN et al, 2007;CARDOZO et al, 2008;DAGAN;LIPSITCH, 2004;RUBINS et al, 1998).…”