Immunogenicity and safety of a 13-valent pneumococcal conjugate vaccine compared to a 23-valent pneumococcal polysaccharide vaccine in pneumococcal vaccine-naive adults

Background

Streptococcus pneumoniae is a major cause of morbidity and mortality among adults 50 years of age and older in the United States. Pneumococcal conjugate vaccines are efficacious against pneumococcal disease in children and may also offer advantages in adults.

Methods

We performed a randomized, modified double-blind trial that compared a single dose of 13-valent pneumococcal conjugate vaccine (PCV13) with 23-valent pneumococcal polysaccharide vaccine (PPSV23) in 831 pneumococcal vaccine naive adults 60–64 years of age. An additional group of 403 adults 50–59 years of age received open-label PCV13. Anti-pneumococcal opsonophagocytic activity (OPA) titers were measured at baseline, and at 1 month and 1 year after vaccination.

Results

In the randomized trial, the month 1 post-vaccination OPA geometric mean titers in the PCV13 group were statistically significantly higher than in the PPSV23 group for 8 of the 12 serotypes common to both vaccines and for serotype 6A, a serotype unique to PCV13, and were comparable for the other 4 common serotypes. The immune response to PCV13 was generally greater in adults 50–59 years of age compared to adults 60–64 years of age. OPA titers declined from 1 month to 1 year after PCV13 administration but remained higher than pre-vaccination baseline titers.

Conclusions

PCV13 induces a greater functional immune response than PPSV23 for the majority of serotypes covered by PCV13, suggesting that PCV13 could offer immunological advantages over PPSV23 for prevention of vaccine-type pneumococcal infection.     

Impact and effectiveness of 23-valent pneumococcal polysaccharide vaccine against invasive pneumococcal disease in the elderly in England and Wales

In 2003 the existing 23-valent pneumococcal vaccine (PPV23) programme for high risk groups was extended to include all ≥65 year olds in England and Wales, starting with ≥80 year olds and moving to 75–79 and 65–74 year olds by 2005. We conducted an ecological study to assess the impact of the extended PPV23 programme on serotype-specific incidence of invasive pneumococcal disease (IPD) and a case–control study to assess vaccine effectiveness (VE) using the national IPD surveillance dataset. Between 1998 and 2006 IPD incidence caused by PPV23 serotypes in the targeted age-groups was unchanged. IPD caused by the serotypes covered by the 7-valent conjugate vaccine (PCV7) introduced for children in 2006 declined in ≥65 year olds after 2006 but was offset by an increase in non-PCV7 serotypes. This increase was similar for the additional 16 serotypes covered by PPV23 and the non-PPV23 serotypes. For the VE study, vaccine history was obtained for controls (n = 1270) with non-PPV23 IPD diagnosed between November 2003 and December 2010 and a subset of cases (n = 1272) matched for age and time period. VE declined from 48% (95% confidence interval; 32–60%) within two years of vaccination to 15% (−3% to 30%) after five years. Although differences in VE by age and having risk conditions were not statistically significant the highest estimates were in the youngest age group (65–74 years) and in those without risk conditions with a VE estimate of 65% (23–84%) within 2 years of vaccination for non-risk 65–74 year olds. VE differed by serotype (p = 0.005), from −23% (−85% to 19%) for serotype 3 to 63% (29–81%) for 12F. In conclusion PPV23 was effective, particularly in healthy under 75 year olds, but protection waned after 5 years. There was no discernible impact of PPV23 on IPD incidence or PCV7-induced serotype replacement, consistent with the modest overall effectiveness, the 45% increased coverage over the former risk-based programme and lack of herd immunity from the PPV23 programme. Based on the VE estimates PPV23 was still considered a cost-effective intervention for the low risk elderly.     

The 13-valent pneumococcal conjugate vaccine (PCV13) elicits cross-functional opsonophagocytic killing responses in humans to Streptococcus pneumoniae serotypes 6C and 7A

The introduction of a 7-valent pneumococcal conjugate vaccine (PCV7) in 2000 dramatically reduced the incidence of invasive pneumococcal disease (IPD) caused by the seven serotypes covered by the vaccine. Following the introduction of PCV7, which contains a serotype 6B conjugate, some decrease in IPD due to serotype 6A was noted suggesting that the serotype 6B conjugate provided some partial cross-protection against serotype 6A. However, no effect on serotype 6C was observed. In 2010, a pneumococcal conjugate vaccine with expanded serotype coverage (PCV13) was introduced that expanded the serotype coverage to 13 serotypes including serotype 6A. To assess whether the 6A conjugate in PCV13 could potentially induce functional anti-6C antibody responses, an opsonophagocytic assay (OPA) for serotype 6C was developed. Randomly chosen subsets of immune sera collected from infants receiving three doses of PCV7 or PCV13 were tested in OPA assays for serotype 6A, 6B and 6C. PCV7 immune sera demonstrated strong OPA responses, defined as percentage of subjects having an OPA titer ≥1:8, to serotype 6B (100% responders), partial responses to serotype 6A (70% responders) but only minimal responses to serotype 6C (22% responders). In contrast, PCV13 immune sera showed strong OPA responses to serotypes 6A (100% responders), 6B (100% responders) and 6C (96% responders). Furthermore, during pre-clinical work it was observed that serotype 7F (included in PCV13) and serotype 7A (not included in PCV13) shared serogroup-specific epitopes. To determine whether such epitopes also may be eliciting cross-functional antibody, PCV13 immune sera were also tested in serotype 7A and 7F OPA assays. All PCV13 immune sera demonstrated OPA responses to both of these serotypes. Taken together these results suggest that immunization with PCV13 has the potential to induce cross-protective responses to related serotypes not directly covered by the vaccine.     

Immunogenicity and safety of a 13-valent pneumococcal conjugate vaccine in adults 70 years of age and older previously vaccinated with 23-valent pneumococcal polysaccharide vaccine

Background

The currently recommended single dose of the 23-valent pneumococcal free polysaccharide vaccine (PPSV23) for adults 65 years of age and older does not provide extended protection into older age. This reflects a significant unmet medical need for alternative strategies to protect older adults against pneumococcal infection, which may be met by the 13-valent polysaccharide conjugate vaccine (PCV13).

Methods

We performed a randomized, modified double-blind trial in 936 adults aged 70 years and older who had previously received PPSV23 at least 5 years before study entry and were now vaccinated with PCV13 or PPSV23. At 1 year after enrollment, all subjects received a follow-on dose of PCV13. Anti-pneumococcal opsonophagocytic activity (OPA) titers were measured before and at 1 month after each vaccination.

Results

Following the enrollment vaccination, OPA titers were significantly greater in the PCV13 group compared to the PPSV23 group for 10 of the 12 serotypes common to both vaccines and to serotype 6A which is unique to PCV13. Responses were noninferior for the other 2 common serotypes. Responses to PCV13 given at 1 year were generally lower in the group that received PPSV23 at enrollment.

Conclusion

In adults aged 70 years and older previously vaccinated with PPSV23, PCV13 was significantly more immunogenic than PPSV23 for most of the common serotypes and for serotype 6A. The OPA responses after a follow-on dose of PCV13 one year later indicate that a prior dose of PPSV23, but not PCV13, diminishes the response to the subsequent administration of PCV13.     

Influence of initial vaccination with 13-valent pneumococcal conjugate vaccine or 23-valent pneumococcal polysaccharide vaccine on anti-pneumococcal responses following subsequent pneumococcal vaccination in adults 50 years and older

Background

Unlike free polysaccharide vaccines, pneumococcal polysaccharide conjugate vaccines (PCVs) induce a T cell-dependent immune response and have the potential to provide an extended duration of protection with repeated vaccinations.

Methods

This was an extension of a previous study in pneumococcal vaccine-naïve adults aged 50–64 years in which adults 60–64 years of age were given 13-valent PCV (PCV13) or 23-valent pneumococcal polysaccharide vaccine (PPSV23) and adults aged 50–59 were given PCV13. In this follow up study conducted about 4 years later, the 60–64 year olds initially given PCV13 received PCV13 or PPSV23, and those initially given PPSV23 received another PPSV23. All adults aged 50–59 years were re-vaccinated with PCV13. Anti-pneumococcal opsonophagocytic activity (OPA) titers were measured before and 1 month after vaccination.

Results

A second PCV13 given about 4 years after a first vaccination induced OPA titers that were significantly higher than those following the initial vaccination for 7 of 13 serotypes in the older group, and 6 of 13 serotypes in the younger group, and responses to the remaining serotypes were largely non-inferior. In contrast, OPA titers following revaccination with PPSV23 were statistically significantly lower for 9 of the 13 serotypes, and non-inferior for the remaining serotypes, when compared to the responses to the first PPSV23. OPA titers in the older adults who received PPSV23 after initial PCV13 were significantly higher than those following a first PPSV23 for 10 of the 13 serotypes.

Conclusion

In adults 50 to 64 years of age, initial vaccination with PCV13 establishes an immune state that results in recall anti-pneumococcal responses upon subsequent vaccination with either conjugated or free polysaccharide vaccine. In contrast, initial vaccination with PPSV23 results in an immune state in which subsequent PPSV23 administration yields generally lower responses compared with the initial responses.     

老年人接种23价肺炎球菌多糖疫苗保护效果的Meta分析

目的 评价60岁以上老年人接种23价肺炎球菌多糖疫苗(PPV23)对侵袭性肺炎球菌疾病(IPD)和肺炎球菌肺炎(PP)的保护效果.方法 电子检索National Center for Biotechnology Information、Cochrane Library、中国生物医学文献数据库、中国期刊全文数据库和万方全文数据库等数据库,将60岁以上老年人接种PPV23流行病学保护效果的随机对照试验、队列研究、病例对照研究纳入研究.合并各项研究中关于接种组和对照组间发生IPD、PP的相对危险度(RR)或比值比(OR).在合并RR或OR有统计学意义的情况下,计算疫苗效力.使用RevMan 5.3软件进行统计分析.结果 共纳入4篇随机对照研究、5篇队列研究和8篇病例对照研究.随机对照研究合并后显示接种PPV23后对IPD和PP的疫苗效力分别是73％(95％CI:10％～92％),64％ (95％ CI:35％ ～80％);队列研究合并后显示对IPD和PP的疫苗效力分别为45％ (95％CI:15％～65％),48％ (95％CI:25％～63％);病例对照研究合并显示对IPD和PP的疫苗效力分别是59％ (95％ CI:35％～74％),45％(95％CI:27％～59％).结论 60岁以上老年人接种PPV23后对IPD和PP均有良好的保护效果,而且由于PPV23覆盖肺炎球菌血清型别较广,可以有效减少IPD、PP发病,值得在60岁以上老年人中推广使用.     

Impact of 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) on childhood pneumonia hospitalizations in Brazil two years after introduction

Introduction

Pneumococcal disease is a major public health problem worldwide. From March to September of 2010, 10-valent pneumococcal non-typeable Haemophilus influenzae protein conjugate vaccine (PHiD-CV) was introduced in the Brazilian childhood National Immunization Program (NIP) in all 27 Brazilian states. The aim of the present study is to report national time-trends in incidence of hospital admissions for childhood pneumonia in Brazil before and after two years of introduction of this new pneumococcal conjugate vaccine.

Methods

Analysis of hospitalization data of children aged 0–4 years in Brazilian public health system with an admission diagnosis of pneumonia from 2002 to 2012 was performed comparing pre (2002–2009) and post-vaccination periods (2011–2012). Hospital number of admission due to pneumonia and all non-respiratory diseases were obtained from DATASUS, the Brazilian government open-access public health database system. Incidence of pneumonia hospitalization was compared to incidence of all non-respiratory admissions.

Results

Admission rates for pneumonia decreased steadily from 2010 to 2012. In children aged less than four years, incidence of pneumonia hospitalizations decreased 12.65% when pre (2002–2009) and post-vaccination introduction periods (2011–2012) were compared and adjusted for seasonality and secular-trend (p < 0.001). On the other hand, non-respiratory admission rates remained stable comparing both periods (p = 0.39).

Conclusion

Childhood pneumonia hospitalization rates were fluctuating prior to 2010 and decreased significantly in the two years after PHiD-CV introduction. Conversely, rate of non-respiratory admissions has shown no decrease. These data are an evidence of the effectiveness and public health impact of this new pneumococcal vaccine.     

The risk of febrile seizures following influenza and 13-valent pneumococcal conjugate vaccines

BackgroundEvidence on the risk of febrile seizures after inactivated influenza vaccine (IIV) and 13-valent pneumococcal conjugate vaccine (PCV13) is mixed. In the FDA-sponsored Sentinel Initiative, we examined risk of febrile seizures after IIV and PCV13 in children 6–23 months of age during the 2013–14 and 2014–15 influenza seasons.MethodsUsing claims data and a self-controlled risk interval design, we compared the febrile seizure rate in a risk interval (0–1 days) versus control interval (14–20 days). In exploratory analyses, we assessed whether the effect of IIV was modified by concomitant PCV13 administration.ResultsAdjusted for age, calendar time and concomitant administration of the other vaccine, the incidence rate ratio (IRR) for risk of febrile seizures following IIV was 1.12 (95% CI 0.80, 1.56) and following PCV13 was 1.80 (95% CI 1.29, 2.52). The attributable risk for febrile seizures following PCV13 ranged from 0.33 to 5.16 per 100,000 doses by week of age.The age and calendar-time adjusted IRR comparing exposed to unexposed time was numerically larger for concomitant IIV and PCV13 (IRR 2.80, 95% CI 1.63, 4.83), as compared to PCV13 without concomitant IIV (IRR 1.54, 95% CI 1.04, 2.28), and the IRR for IIV without concomitant PCV13 suggested no independent effects of IIV (IRR 0.94, 95% CI 0.63, 1.42). Taken together, this suggests a possible interaction between IIV and PCV13, though our study was not sufficiently powered to provide a precise estimate of the interaction.ConclusionsWe found an elevated risk of febrile seizures after PCV13 vaccine but not after IIV. The risk of febrile seizures after PCV13 is low compared to the overall risk in this population of children, and the risk should be interpreted in the context of the importance of preventing pneumococcal infections.     

Compared effectiveness of the 7-valent pneumococcal conjugate vaccine in children with the 13-valent vaccine in adults

13-valent-pneumococcal conjugated vaccine was recently approved in the USA and Europe for adults 50 years of age or more. But this approval was followed by recommendations limiting its use to immunocompromised and asplenic patients. The extension of indications to adults was based on the well-demonstrated clinical effectiveness in infants less than 2 years of age, and on a better immune response either quantitatively or qualitatively with conjugated vaccines compared to the immunogenicity of plain polysaccharide vaccines. Nevertheless, the issue was to know whether results observed with the 7-valent pneumococcal conjugate vaccine in children are reproducible in adults with the 13-valent. The answer was given by comparing the epidemiological and physiopathological data, and the immunological response of the two populations. Very few clinical effectiveness studies in adults are available. We had for aim to assess these various issues in infants and adults. A lot of questions remain, such as the unknown impact of serotype replacement with the 13-valent pneumococcal conjugated vaccine on the clinical epidemiology and emergent Streptococcus pneumoniae pathogenicity, while waiting for the CAPITA study results expected in 2014.     

23-valent pneumococcal polysaccharide vaccine improves survival in dialysis patients by preventing cardiac events

BackgroundImmunodeficient patients are recommended to receive pneumococcal vaccination. However, there is limited evidence showing effectiveness of the polysaccharide vaccine. Polysaccharide vaccination has shown an association with cardiovascular event risk reduction. We assessed the efficacy of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in relation to the risk of hospitalization and death due to pneumonia and acute cardiac events.MethodsThe medical records of all dialysis patients attending our 8 study centers in 2010 were studied, and we selected 1038 consecutive patients. One-to-one propensity score matching was used to correct for potential selection bias in a PPSV23-vaccinated group versus a non-vaccinated group, and a total of 510 patients were identified for outcome analysis. Time to first admission, or deaths due to all-cause pneumonia or cardiac events until 2015 were compared between both groups.ResultsThe all-cause death rate was significantly decreased in the PPSV23-vaccinated group, (hazard ratio [HR] 0.62, 95% confidence interval [CI]; 0.46–0.83, P = 0.002). All-cause death was considered to be a competing risk for the other outcomes. Further outcomes were evaluated by competing risk analysis adjusting for mortality. There was no statistically significant difference in the hospitalization rate for pneumonia; however, the hospitalization rate due to cardiac events was significantly lower in the PPSV23-vaccinated group than in the non-vaccinated group (HR 0.44, 95% CI; 0.20–0.96, P = 0.040). There was no statistically significant difference in the death rate due to pneumonia; however, the rate of cardiac death was significantly lower in the PPSV23-vaccinated group than in the non-vaccinated group (HR 0.36, 95% CI; 0.18–0.71, P = 0.003).ConclusionsThe PPSV23 vaccination is associated with a good prognosis and a low-risk of cardiac events in dialysis patients; however, there was no evidence indicating enhanced protective efficacy against pneumonia, suggesting the PPSV23 vaccination might improve the prognosis by directly preventing cardiovascular events.     

Cost-effectiveness analyses of 15- and 20-valent pneumococcal conjugate vaccines for Japanese elderly

BackgroundDespite the 23-valent pneumococcal polysaccharide vaccine (PPSV23) vaccination programme implementation, pneumococcal disease (PD) remains an important cause of morbidity and mortality among the elderly in Japan, particularly since childhood pneumococcal conjugate vaccine (PCV) vaccination programme continues to alter the serotype PD distribution among the elderly. Recently, in the United States, PCV15/PCV20 were recommended for adults aged ≥ 65 years and those aged 19–64 years with certain underlying conditions. In Japan, PCV15 is under the approval application process and PCV20 undergoing clinical trials, which has warranted the need in evaluating their value for money.MethodsWe conducted cost-effectiveness analyses with Markov model and calculated incremental cost-effectiveness ratios of PCV15/PCV20 vaccination programme compared to status quo from payers’ perspective. Transition probabilities and utility weights in estimating quality-adjusted life-year (QALY), and disease treatment costs were either estimated or obtained from literature. To reflect the situation of COVID-19 pandemic, epidemiological data from 2020 and beyond were used.ResultsCompared to the current vaccination programme, PCV20 vaccination programme gained more QALYs with less cost, while PCV15 vaccination programme cost ¥35,020 (US$318, US$1 = ¥110) to gain an additional QALY. Replacing PPSV23 vaccination programme with PCV20 vaccination programme is cost-saving. One-way sensitivity analyses revealed that lower VE limits of PCVs against non-bacteremic pneumonia (NBP) have large impact to change the result from PCV20 vaccination programme dominated PPSV23 vaccination programme to PPSV23 vaccination programme dominated PCV20 vaccination programme.ConclusionIn the COVID-19 era, replacing current PPSV23 with a single-dose PCV15- or PCV20 immunisation programme for 65-year-old adults in Japan is highly cost-effective, while the PCV 20 vaccination programme was observed to be more favourable.     

Ten years of experience with the pneumococcal conjugate 7-valent vaccine in children

In children, pneumococcus became the predominant infectious agent, after the routine use of the Hib conjugate vaccine dramatically decreased Haemophilus Influenzae type b prevalence. The incidence of invasive pneumococcal infections (IPI) and of non-invasive infections due to vaccine serotypes (VS) decreased by 80% in Europe along with a 30–40% decrease in the global incidence of IPI in this age group, after the implementation of Prevenar 7^® routine immunization in children below 2 years of age. The decrease of IPI due to VS in other age groups was an indirect benefit. The moderate increase of non-vaccinal serotype IPI incidence did not impede the benefit of the overall program. Serotype 19A was the most frequent and carried resistance to antibiotics. Prevenar 13^®, a second-generation vaccine with six new serotypes, replaced Prevenar 7^® in most countries after 2010, with available evidence of its effectiveness (United Kingdom, US, France).     

13价肺炎球菌结合疫苗成人应用免疫原性和效果

肺炎球菌是导致成人特别是老年人群严重感染和死亡的重要原因之一。13价肺炎球菌结合疫苗（PCV13）已在全球多个国家或地区获得批准用于预防成人侵袭性和非侵袭性肺炎球菌性疾病等,但在中国大陆尚未批准应用于成人。本文综述了PCV13在全球其他国家和地区成人中的免疫原性和效果,为优化我国PCV13疫苗免疫程序提供依据。     

HIV-1感染者接种23价肺炎疫苗的效果观察研究

目的 观察HIV-1感染者接种23价肺炎球菌多糖疫苗(23-valent pneumococcal polysaccharide vaccine,PPV23)的效果,评价疫苗接种的安全性、保护效果以及成本效益,为相关政策的制定提供参考。方法 用自行设计的调查问卷,通过电话或者面对面访谈对蓝山县2017—2019年接种过PPV23的145名HIV-1感染者进行调查,收集接种PPV23前后一年内接种者肺炎相关疾病的发生情况、接种疫苗后不良反应、相关疾病诊疗信息及费用情况等。结果 145名HIV-1感染者接种PPV23后,患呼吸道疾病和肺炎的发病率等都低于接种疫苗前(P<0.05),但是CD4⁺T细胞计数没有改变。结论 HIV-1感染者接种PPV23有助于降低HIV-1感染者发生肺部机会性感染,有良好的安全性和经济效益,值得在HIV-1感染人群中推广。     

Immunogenicity of 13-valent pneumococcal conjugate vaccine among children with underlying medical conditions

BackgroundStreptococcus pneumoniae is a leading cause of vaccine-preventable disease in children under 5 years. Immunocompromised children and those with underlying diseases are at increased risk of severe complications from vaccine-preventable infections. We studied the humoral immune response to the 13-valent pneumococcal conjugate vaccine (PCV13) in children with HIV-infection, kidney or lung disease and compared this to the response in healthy control children.MethodsChildren aged 12–71 months with underlying conditions including HIV-infection and those with kidney and lung diseases (at-risk children), and a healthy control group were vaccinated with PCV13. The at-risk children received two doses of PCV13 and the controls received one dose. Serotype-specific antibodies for all PCV13 serotypes were measured by a luminex-based enzyme immunoassay at baseline and post-vaccination.ResultsAfter the first PCV13 dose, the fold-increase in serotype-specific antibody geometric mean concentrations (GMCs) from baseline and the percentage of participants with ≥4-fold-increase in antibody concentrations was similar between the control and at-risk children. GMCs were, however, lower for three of the 13 serotypes in HIV-infected children, higher for serotype 6B in children with kidney disease and higher for serotypes 6B and 14 in children with lung disease. After second vaccine dose HIV-infected children had an increase in GMCs from post-first dose for nine serotypes but the percentage of participants with ≥4-fold-increase from baseline was similar post-second dose compared to post-first dose except for serotypes 6A and 19F. In children with kidney or lung diseases the immune responses after second vaccine dose were similar to post-first dose. Attenuated responses were observed for serotypes 3 and 19A in all study-groups, which was especially pronounced in the at-risk groups.ConclusionAll study-groups mounted an immune response to PCV13, with the at-risk groups having responses that were mostly similar to the control children.     

Effectiveness of the new serotypes in the 13-valent pneumococcal conjugate vaccine

Efficacy of the new serotypes in the 13-valent pneumococcal conjugate vaccine (PCV13) against invasive pneumococcal disease (IPD) was based on a putative correlate of protection. In England and Wales, PCV13 replaced PCV7 in the 2, 4, and 13 month schedule in April 2010. Using non-vaccine type IPD cases as controls, we estimated vaccine effectiveness (VE) for the new serotypes. Among 166 IPD cases in PCV13 eligible children reported by July 2011 with known serotype and vaccination status, VE for 2 doses under a year was 78% (95% confidence interval −18% to 96%) and 77% (38-91%) for one dose over a year. VE for 7F and 19A was 76% (21-93%) and 70% (10-90%) respectively for ≥one dose. VE for serotypes 1 and 3 was 62% and 66% respectively although confidence intervals spanned zero. IPD due to PCV13-only serotypes halved in children under 2 years in the study period.     

The immunogenicity and safety of pneumococcal conjugate vaccine in human immunodeficiency virus-infected Thai children

Background

HIV-infected children have high risk of invasive pneumococcal disease (IPD) despite receiving highly active antiretroviral therapy (HAART). This study aimed to determine the immunogenicity and safety of a 7-valent pneumococcal conjugate vaccine (PCV-7) in Thai HIV-infected children compared to HIV-exposed uninfected children.

Methods

A prospective study was conducted among children 2 months to 9 years. The number of PCV-7 doses depended upon age and HIV status; 2-6 months of age: 3 doses; 7-23 months of age: 2 doses; HIV-infected child ≥24 months: 2 doses and HIV-exposed child ≥24 months: 1 dose. Serotype-specific pneumococcal IgG antibody concentrations were measured at baseline and 28 days after complete vaccination. The primary end point was the proportion of children who achieved serotype-specific IgG antibody concentration at a cut off level ≥0.35 μg/mL. Secondary end points were a 4-fold increase in serotype-specific IgG antibody, rates of adverse events and predictors for seroconversion among HIV-infected children.

Results

Fifty-nine HIV-infected and 30 HIV-exposed children were enrolled. The median (IQR) age was 97 (67-111) and 61 months (51-73), respectively (p < 0.001). Among HIV-infected children, current and nadir CD4 counts were 1079 cell/mm³ and 461 cell/mm³, respectively. The proportion of children who achieved pneumococcal IgG ≥0.35 μg/mL was in the range of 85-98% in HIV-infected and 83-100% in HIV-exposed children depending on serotype. The lowest response was to serotype 6B in both groups. The 4-fold increase in serotype-specific IgG concentrations was similar between HIV-infected and HIV-exposed groups, except for serotype 9V (p = 0.027). HIV-infected children who had a history of AIDS had a lower antibody response to serotype 23F (p = 0.025). Seven (12%) HIV-infected children had a grade 3 local reaction.

Conclusion

PCV-7 is highly immunogenic and safe among HIV-infected children treated with HAART. The use of the pneumococcal conjugate vaccine among HIV-infected children is encouraged in order to prevent IPD.     

Cost-effectiveness of the introduction of the pneumococcal polysaccharide vaccine in elderly Colombian population

Background

Streptococcus pneumoniae causes community-acquired pneumonia, otitis media and meningitis, with higher incidences at the extremes of life. PPV-23 vaccine is widely used in prevention of pneumonia and invasive pneumococcal disease in older adults in developed countries. We developed an evaluation of cost-effectiveness of implementing PPV-23 in Colombian population over 60 years.

Methods

The number of cases of pneumonia and meningitis in patients over 60 years and the proportion by S. pneumoniae was estimated based on a review of literature. A decision tree model with a 5-year time horizon was built to evaluate the cost-effectiveness of the implementation of the PPV-23 in this population. Direct health care costs of out- and in-patients were calculated based on expenditure records from the Bogota public health system. Incremental cost-effectiveness ratios per life saved and per year of life gained were estimated based on the decision tree model. Deterministic and probabilistic sensitivity analyses were performed.

Results

Without vaccination 4460 (range 2384-8162) bacteremic pneumococcal pneumonias and 141 (range 73-183) pneumococcal meningitis would occur among people over 60 years old in Colombia. In the first year, vaccination with PPV-23 at US$8/dose would save 480 (range 100-1753) deaths due to Invasive and non-invasive pneumococcal disease. Vaccination would results in US$3400/deaths averted (range US$1028-10,862) and US$1514/life years gained (range US$408-5404).

Conclusion

Vaccination with PPV-23 in over 60 years is a highly cost-effective public health measure in Colombia. Despite some limitations, the results are robust, and may help developing countries to perform informed decisions about the introduction of the vaccine.     

接种13价肺炎球菌结合疫苗对就诊儿童肺炎链球菌血清型和耐药性的影响

目的  了解就诊儿童肺炎链球菌(Streptococcus pneumoniae, Spn)血清型分布和耐药特征,探索接种13价肺炎球菌结合疫苗(13-valent pneumococcal conjugate vaccine, PCV13)对Spn的影响。方法  收集2017—2019年苏州大学附属儿童医院疫苗接种信息明确的就诊儿童的Spn菌株,根据疫苗接种情况进行分组,并采用荚膜肿胀法进行血清分型,E-test法检测菌株抗生素的耐药性,比较是否接种PCV13对Spn血清型和耐药性的差别。结果  共收集692株Spn,其中20株分离自接种PCV13儿童。接种组中常见的血清型为19F、6B、19A、23F,对照组中常见的血清型为19F、6B、23F、19A、14,两组血清型分布差别无统计学意义(P=0.868),PCV13血清型覆盖率分别为70.0% 和72.4%(P=0.491)。所有菌株对红霉素、四环素、克林霉素高度耐药,且多重耐药率达98.5%。接种组和对照组的Spn菌株对青霉素的不敏感率分别为5.0%和9.1%(P=0.804)。结论  苏州大学附属儿童医院监测就诊儿童Spn血清型以PCV13覆盖的血清型为主,菌株对β-内酰胺类抗生素的耐药性有所下降,但对红霉素等其他常用抗菌药物的耐药性依旧严峻,并存在大量的多重耐药情况。尚未观察到接种PCV13对菌株血清型分布及降低抗生素耐药性的明显效果。     

Immunogenicity and safety of the 13-valent pneumococcal conjugate vaccine compared to 23-valent pneumococcal polysaccharide in immunocompetent adults: A systematic review and meta-analysis

Background

Despite the use of 23-valent pneumococcal polysaccharide vaccine (PPV23) in adults there is substantial morbidity and mortality in the elderly due to pneumococcal infections. Since 2010, the 13-valent pneumococcal conjugate vaccine (PCV13) is in use for infant immunization programs to reduce rates of pneumococcal disease, but is not routinely used in adults. Recent literature suggests PCV13 may be used in adult vaccination programs as well.