Phase 3 trial evaluating the immunogenicity, safety, and tolerability of manufacturing scale 13-valent pneumococcal conjugate vaccine

Associations between geographic region and immune response variations to pneumococcal conjugate vaccines in clinical trials: A systematic review and meta-analysis

OBJECTIVE

Geographic region can be an important source of variation in the immune response to pneumococcal conjugate vaccines (PCV). The aim of this study was to collate data from available PCV clinical trials in order to characterize the differences in antibody responses in different countries.

METHODS

A systematic review and meta-analysis was conducted to examine the difference in antibody responses after primary series of PCVs in infants, associated with geographic regions, compared with each other and with the different PCVs using random-effects models.

RESULTS

A total of 69 trials were included. Studies conducted in the Western Pacific Region (WPR) showed higher geometric mean concentrations (GMC) compared to studies conducted in Europe. The pooled GMC for serotype 4 after three doses of PCV7 in the WPR was 5.19 μg/ml (95% confidence interval 4.85-5.53 μg/ml), while for studies conducted in Europe this was 2.01 μg/ml (95% confidence interval 1.88-2.14 μg/ml). The IgG GMC ratios among the WPR versus European regions ranged from 1.51 to 2.87 for PCV7, 1.69 to 3.22 for PCV10, and 1.49 to 3.08 for PCV13.

CONCLUSIONS

Studies conducted in the WPR generally showed greater antibody responses than the studies conducted in Europe. Indications of differences among geographic regions highlight the fact that further research is needed to compare the biological factors contributing to immune responses, which may affect vaccination schedules.

Immunogenicity and Safety of the 13-Valent Pneumococcal Conjugate Vaccine Administered in a 3 + 1 versus 2 + 1 Dose Schedule Among Infants in China

BACKGROUND

13-valent pneumococcal conjugate vaccine (PCV13) was licensed in China based on immunologic noninferiority to 7-valent PCV (PCV7). As part of the noninferiority study, immunogenicity and safety of PCV13 administered as a 3- or 2-dose infant series followed by a toddler dose were examined in healthy Chinese infants.

METHODS

Infants (42- to 77-days-old) were randomized to a 3-dose PCV13 or PCV7 infant series administered double-blind at 3, 4 and 5 months or PCV13 administered open-label at 2, 4 and 6 months and a 2-dose open-label series at 3 and 5 months; all subjects received a toddler dose (12 months). Serotype-specific immunoglobulin G (IgG) concentrations were measured 1 month after the infant series and before and after the toddler dose. Opsonophagocytic activity (OPA) was measured in a subset of subjects at each time point. Safety was evaluated.

RESULTS

One month after the infant series, serotype-specific immune responses (IgG ≥ 0.35 µg/mL) were similar for the 2- versus 3-dose schedules, except for serotype 6B, which was significantly lower in the 2-dose group [70.1% in the PCV13 (3, 5 + 12 mo) group vs. 93.2% in the PCV13 (3, 4, 5 + 12 mo) group and 94.7% in the PCV13 (2, 4, 6 + 12 mo) group]. IgG geometric mean concentrations and OPA geometric mean titers trended numerically higher with 3- versus 2-dose schedules. No significant differences in immunogenicity were observed between the 3- versus 2-dose schedules after the toddler dose. PCV13 was well-tolerated across all schedules.

CONCLUSIONS

PCV13 administered as a 3- or 2-dose infant series followed by a toddler dose was immunogenic and well tolerated in healthy Chinese infants and likely protective against PCV13 serotypes; immune responses with a 2-dose schedule were lower for some serotypes.

TLR7/8 adjuvant overcomes newborn hyporesponsiveness to pneumococcal conjugate vaccine at birth

Infection is the most common cause of mortality in early life, and immunization is the most promising biomedical intervention to reduce this burden. However, newborns fail to respond optimally to most vaccines. Adjuvantation is a key approach to enhancing vaccine immunogenicity, but responses of human newborn leukocytes to most candidate adjuvants, including most TLR agonists, are functionally distinct. Herein, we demonstrate that 3M-052 is a locally acting lipidated imidazoquinoline TLR7/8 agonist adjuvant in mice, which, when properly formulated, can induce robust Th1 cytokine production by human newborn leukocytes in vitro, both alone and in synergy with the alum-adjuvanted pneumococcal conjugate vaccine 13 (PCV13). When admixed with PCV13 and administered i.m. on the first day of life to rhesus macaques, 3M-052 dramatically enhanced generation of Th1 CRM-197-specific neonatal CD4⁺ cells, activation of newborn and infant Streptococcus pneumoniae polysaccharide-specific (PnPS-specific) B cells as well as serotype-specific antibody titers, and opsonophagocytic killing. Remarkably, a single dose at birth of PCV13 plus 0.1 mg/kg 3M-052 induced PnPS-specific IgG responses that were approximately 10-100 times greater than a single birth dose of PCV13 alone, rapidly exceeding the serologic correlate of protection, as early as 28 days of life. This potent immunization strategy, potentially effective with one birth dose, could represent a new paradigm in early life vaccine development.

Safety and Immunogenicity of Pneumococcal Conjugate Vaccine in Preterm Infants: A Meta-Analysis

OBJECTIVE

To assess the safety and immunogenicity of pneumococcal conjugate vaccine (PCVs) in preterm infants.

METHODS

In accordance with the PRISM (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement (as of May 2015), a meta-analysis was conducted to evaluate the safety and immunogenicity of PCVs in preterm infants.

RESULTS

Ten thousand nine hundred sixty full-term infants and 2131 preterm infants with 344 preterm infants of <2500 g birth weight [low-birth weight (LBW)] were included, and all the subjects were immunized with either PCV-7, PCV-10 or PCV-13 in this random-effects meta-analysis. For safety, the range of risk ratio (RRs) for local reaction was from 0.88 to 1.02 and from 0.94 to 1.24 for systematic reaction respectively. For immunogenicity, either post-primary or booster vaccination with PCV-7, PCV-10 or PCV-13, genomic mean concentration (GMC) of serotypes 4, 6B, 9 V, 19F and 23F was always less in preterm infants than in full-term infants, in which huge comparison of GMC was found in serotype 19F(SMD = -0.393, 95%CI:-0.612 ~ 0.175). After primary vaccination, the combined risk ratio (RRs) of immune response against seven common serotypes and additional serotype 1 was approximated to 1.00 with narrow 95 % confidence interval (CI) between preterm infants and full-term infants, and at least 91 % sero-conversion of two additional serotypes, 5 and 7F in two cohorts was observed. Furthermore, between very-low-birth-weight (VLBW) infants of <1500 g and 1501 ~ 2500 g, overall RRs of immune response to PCV-7 administration was 0.98 (95%CI: 0.96 ~ 1.00).

CONCLUSIONS

Preterm infants have a great tolerance to PCV-7, PCV-10 or PCV-13 vaccination. PCV-7 could elicit optimal immune response post vaccination in preterm infants, even in VLBW infants.

Immunogenicity and Safety of 13-valent Pneumococcal Conjugate Vaccine Compared With 7-valent Pneumococcal Conjugate Vaccine Among Healthy Infants in China

BACKGROUND

Immunogenicity and safety of 13-valent pneumococcal conjugate vaccine (PCV13) were compared with 7-valent pneumococcal conjugate vaccine (PCV7) in Chinese infants.

METHODS

Healthy infants aged 2 months were randomized to a double-blind 3-dose infant series plus 1 toddler dose of PCV7 or PCV13 at 3, 4, 5 and 12 months or open-label PCV13 at 2, 4, 6 and 12 months. Serotype-specific immunoglobulin G (IgG) binding and functionality were measured 1 month after the infant series and after the toddler dose. Local reactions, systemic events and adverse events were assessed postvaccination.

RESULTS

For the 7 common serotypes, serotype-specific binding IgGs elicited by PCV13 were noninferior to PCV7 after the 3-dose infant series; functional antibodies were comparable. For the 6 additional serotypes, PCV13 recipients had significantly higher serotype-specific IgGs and functional antibodies than PCV7 recipients after the infant series. The toddler dose boosted the immune response. Local reactions and systemic events were mild in severity and similar across groups. No new safety signals were identified.

CONCLUSIONS

For the 7 common serotypes, serotype-specific binding IgG after 2 different 3-dose regimens of PCV13 were noninferior to PCV7 responses. PCV13 recipients had significantly higher immune responses to the 6 additional serotypes. PCV13 is expected to provide pneumococcal disease protection comparable to PCV7 for the common serotypes and further protection against disease caused by the 6 additional serotypes. Safety of PCV7 and PCV13 was comparable.

Immunogenicity and safety of a 13-valent pneumococcal conjugate vaccine administered to older infants and children naïve to pneumococcal vaccination

BACKGROUND

Streptococcus pneumoniae infections are a major cause of morbidity and mortality in children <5 years old worldwide. To increase serotype coverage globally, a 13-valent pneumococcal conjugate vaccine (PCV13) has been developed and approved in many countries worldwide.

OBJECTIVE

Assess the safety and immunogenicity of PCV13 in healthy older infants and children naïve to previous pneumococcal vaccination.

METHODS

This was a phase 3, open-label, multicenter study conducted in Polish children (N=354) who were vaccinated according to 3 age-appropriate catch-up schedules: Group 1 (aged 7 to <12 months) received two PCV13 doses with a booster at 12-16 months of age; Group 2 (aged 12 to <24 months) received two vaccine doses only; and Group 3 (aged 24 to <72 months) received a single dose of PCV13. Statistical analyses were descriptive. The proportion of immunological "responders" achieving serotype-specific antipneumococcal polysaccharide concentrations ≥0.35μg/mL, 1-month after the last dose of vaccine, was determined for each vaccine serotype. In addition, antipolysaccharide immunoglobulin (Ig) G geometric mean concentrations (GMCs) were calculated. Safety assessments included systemic and local reactions, and adverse events.

RESULTS

The proportion of immunological responders was ≥88% across groups for all serotypes. Antipolysaccharide IgG GMCs were generally similar across groups. Each schedule elicited immune response levels against all 13 serotypes comparable to or greater than levels previously reported in infants after a 3-dose series. The 3 catch-up schedules had similar tolerability and safety profiles; a trend was present towards greater local tenderness with increasing age and subsequent dose administration.

CONCLUSIONS

Immunological responses and safety results support the use of PCV13 for catch-up schedules in older infants and children naïve to pneumococcal vaccination.

Pneumococcal 13-valent conjugate vaccine for the prevention of invasive pneumococcal disease in children and adults

Pneumococcal disease remains a global problem despite the availability of effective conjugate vaccines. The 13-valent pneumococcal conjugate vaccine (PCV13) extends the valency of PCV7 by including six additional serotypes highly associated with invasive pneumococcal disease (IPD). Comparisons between PCV13 and PCV7 or the pneumococcal polysaccharide vaccine have established noninferiority of PCV13 for both safety and immunogenicity profiles for use in children and adults, respectively. At the end of 2011, PCV13 had been approved and launched in 104 countries worldwide, with 54 including the vaccine in their pediatric national immunization program. Surveillance data from early adopters of PCV13 has indicated reductions are occurring in both overall IPD and IPD caused by the six non-PCV7 serotypes; early reports of serotype replacement in carriage are also emerging. While serotype replacement for PCV7 was observed to varying degrees for both carriage and disease, the extent to which this will occur for PCV13 is yet to be determined.

Development and clinical evaluation of Prevnar 13, a 13-valent pneumocococcal CRM197 conjugate vaccine

Pneumococcus is the leading cause of bacterial illness in children worldwide. The development, clinical evaluation, and postlicensure impact of the pneumococcal CRM(197) protein conjugate vaccine, PCV13, (Prevnar 13®) builds upon the excellent safety and substantial effectiveness of PCV7 (Prevnar®) in preventing pneumococcal disease in children. PCV13 adds pneumococcal serotypes 1, 3, 5, 6A, 7F, and 19A to serotypes 4, 6B, 9V, 14, 18C, 19F, 23F in PCV7 to provide comprehensive coverage for over 85% of epidemiologically important pneumococcal serotypes in the United States and throughout the world. PCV13 development required demonstration of immunologic responses to the 13 serotypes contained in the vaccine that were noninferior to the responses elicited by PCV7, and demonstration of a satisfactory safety profile. Studies were also performed to demonstrate compatibility with other childhood vaccines. Now licensed in many countries worldwide, PCV13 shows significant promise for expanded protection against pneumococcal disease in children.

Use of the 13-valent pneumococcal conjugate vaccine in infants and young children

INTRODUCTION

The inclusion of the heptavalent pneumococcal conjugate vaccine (PCV7) in the immunization schedule of infants and young children has greatly reduced the incidence of invasive and non-invasive diseases due to Streptococcus pneumoniae. However, as PCV7 has some limitations, new vaccines containing more pneumococcal serotypes have been developed. Only two of these have so far reached the market: a 10-valent preparation containing the PCV7 serotypes plus serotypes 1, 5 and 7F (PCV10), and a 13-valent vaccine containing the PCV7 serotypes plus serotypes 1, 3, 5, 6A, 7F and 19A (PCV13).

AREAS COVERED

The main aim of this review is to discuss the reasons that have led to the formulation of PCV13, its immunogenicity, safety and tolerability and the recommendations concerning its use in children.

EXPERT OPINION

There is no doubt that a pneumococcal conjugate vaccine with the composition of PCV13 has significantly increased the possibility of preventing pneumococcal disease. Its immunogenicity, safety and tolerability seem to be optimal, as does its cost-effectiveness. However, despite these favorable premises, it cannot be considered the final preparation for the prevention of pneumococcal disease, and it is likely that a new vaccine capable of covering all pneumococcal serotypes will be needed in the future.

The pharmacoeconomics of pneumococcal conjugate vaccines in Latin America

Streptococcus pneumoniae continues to be the most important causative agent of invasive bacterial infections in children and is the most common cause of vaccine-preventable deaths in children less than 5 years of age. Due to some conditions in the Latin America region, economic assessments of pneumococcal conjugate vaccines (PCVs) have unique characteristics. First, distribution of S. pneumoniae serotypes, and thus coverage by vaccines that incorporate certain serotypes, varies within the region and compared with other parts of the world. Second, the mortality rate of pneumococcal infections in developing countries is significantly higher than in the US and Europe. Third, the economies of the Latin American region are very different from those of developed countries. For these reasons, the Pan American Health Organization (PAHO) is promoting the need for economic valuation studies of the impact of pneumococcal vaccines Latin America. Given the importance of pneumonia in the burden of pneumococcal disease in Latin America, the number of pneumonia cases prevented by the vaccine has a large impact on the economic valuation of PCVs, due to a strong correlation with numbers of deaths averted, quality-adjusted life-years (QALYs) gained or disability-adjusted life-years (DALYs) avoided. In terms of cost, analysis of impact on acute otitis media (short-term) and sequelae (long-term) show a significant and important expenditure avoided by vaccination. Cost-effectiveness is significantly modified by vaccine cost, mortality due to pneumonia, vaccine efficacy/effectiveness and herd immunity. Finally the validity of certain assumptions based on the uncertainty of the data should be considered in economic assessments of new PCVs. These include assumptions related to the impact on otitis media, estimates of efficacy/effectiveness based on measured antibody levels and the extrapolation to PCV10 and PCV13 of previous experience with PCV7.