Emilio A. Emini

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.

Safety, tolerability, and immunologic noninferiority of a 13-valent pneumococcal conjugate vaccine compared to a 7-valent pneumococcal conjugate vaccine given with routine pediatric vaccinations in Germany

13-valent pneumococcal conjugate vaccine (PCV13) was compared to PCV7 in infants administered 4 doses. For the 7 common serotypes, PCV13- and PCV7-elicited responses showed comparable percent responders achieving 0.35mug/mL IgG threshold (exception 6B, 77.5% versus 87.1%, respectively) and OPA titers of 1:8; IgGs were lower than PCV7 but functional responses were generally comparable. For the 6 additional serotypes, PCV13-elicited IgG and functional OPA responses were notably greater than PCV7. The toddler dose boosted immune responses. Vaccines were comparable with regard to safety. PCV13 should be as effective as PCV7 in preventing pneumococcal disease caused by the common serotypes and may provide protection against the additional serotypes.

Immunogenicity and Safety of 13-Valent Pneumococcal Conjugate Vaccine in Infants and Toddlers

BACKGROUND: 7-Valent pneumococcal conjugate vaccine (PCV7 [Prevnar, Wyeth Pharmaceuticals Inc, Philadelphia, PA], serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F) is effective in preventing vaccine-serotype pneumococcal disease. 13-Valent pneumococcal conjugate vaccine (PCV13) (PCV7 serotypes plus 1, 3, 5, 6A, 7F, and 19A) was designed to provide broader pneumococcal disease coverage. We evaluated the immunogenicity and safety of PCV13 compared with PCV7. METHODS: Infants received PCV13 or PCV7 at ages 2, 4, 6, and 12 to 15 months with routine pediatric vaccinations. Pneumococcal anticapsular polysaccharide-binding immunoglobulin G responses and functional antipneumococcal opsonophagocytic activity were assessed 1 month after dose 3, before the toddler dose, and 1 month after the toddler dose. Safety and tolerability were also assessed. RESULTS: For the 7 common serotypes, PCV13-elicited immunoglobulin G titers were noninferior to those elicited by PCV7, although PCV13 responses were generally somewhat lower. PCV13 also elicited functional opsonophagocytic activity comparable with that elicited by PCV7. For the 6 additional serotypes in PCV13, PCV13 elicited binding and functional antibody levels notably greater than those in PCV7 recipients. After PCV13 immunization, concordance between antipolysaccharide and opsonophagocytic responses was noted for all 13 serotypes. The PCV13 toddler dose resulted in higher immune responses compared with infant-series doses. Safety and tolerability were comparable; reactogenicity was generally mild. CONCLUSIONS: PCV13 will be as effective as PCV7 in the prevention of pneumococcal disease caused by the 7 common serotypes and could provide expanded protection against the 6 additional serotypes. The PCV13 safety profile was comparable to that of PCV7.

Safety and Immunogenicity of a 13-Valent Pneumococcal Conjugate Vaccine Compared to Those of a 7-Valent Pneumococcal Conjugate Vaccine Given as a Three-Dose Series with Routine Vaccines in Healthy Infants and Toddlers

ABSTRACT A 13-valent pneumococcal conjugate vaccine (PCV13) has been developed to improve protection against pneumococcal disease beyond that possible with the licensed 7-valent vaccine (PCV7). This study compared the safety and immunogenicity of PCV13 with those of PCV7 when given as part of the pediatric vaccination schedule recommended in Italy. A total of 606 subjects were randomly assigned to receive either PCV13 or PCV7 at 3, 5, and 11 months of age; all subjects concomitantly received diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated polio-Haemophilus influenzae type B (DTaP-HBV-IPV/Hib) vaccine. Vaccine reactions were monitored. Antibody responses to DTaP-HBV-IPV/Hib antigens, serotype-specific anticapsular polysaccharide IgG responses, and antipneumococcal opsonophagocytic assay (OPA) activity were measured 1 month after the two-dose primary series and 1 month after the toddler dose. Overall, the safety profile of PCV13 was similar to that of PCV7. The response to DTaP-HBV-IPV/Hib antigens was substantially the same with both PCV13 and PCV7. PCV13 elicited antipneumococcal capsular IgG antibodies to all 13 vaccine serotypes, with notable increases in concentrations seen after the toddler dose. Despite a lower immunogenicity for serotypes 6B and 23F after the primary series of PCV13, responses to the seven common serotypes were comparable between the PCV13 and PCV7 groups when measured after the toddler dose. PCV13 also elicited substantial levels of OPA activity against all 13 serotypes following both the infant series and the toddler dose. In conclusion, PCV13 appeared comparable to PCV7 in safety profile and immunogenicity for common serotypes, demonstrated functional OPA responses for all 13 serotypes, and did not interfere with immune responses to concomitantly administered DTaP-HBV-IPV/Hib 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.

Immunogenicity and reactogenicity of a 13-valent-pneumococcal conjugate vaccine administered at 2, 4, and 12 months of age: a double-blind randomized active-controlled trial.

Background: A 2-, 4-, and 12-month schedule of a novel 13-valent-pneumococcal conjugate vaccine (PCV13), containing serotype 1, 3, 4, 5, 6A, 6B 7F, 9V, 14, 18C, 19A, 19F, and 23F polysaccharides individually conjugated to CRM197 was evaluated in a randomized, double-blind, controlled infant study. Methods: Two hundred eighty-six healthy infants received PCV13 or the 7-valent-pneumococcal conjugate vaccine (PCV7) at 2, 4, and 12 months of age, alongside a serogroup C meningococcal (MenC) vaccine (2 and 4 months of age), DTaP-IPV-Hib (2, 3, and 4 months), and a Hib-MenC vaccine (12 months). Specific antibody responses were assessed at age 5, 12, and 13 months. Results: At 13 months of age, >97% of PCV13 recipients had pneumococcal serotype-specific serum IgG concentrations ≥0.35 &mgr;g/mL for each vaccine serotype except serotype 3 (88.2%), and at least 93% of PCV13 recipients had OPA titers ≥1:8 for each serotype. At 5 months, 110/114 (96.5%) of PCV13 recipients and 100/102 (98.0%) of PCV7 recipients had serum anti-PRP (Hib) IgG concentration ≥0.15 &mgr;g/mL (difference, 1.5%; CI, −7.1%–3.7%), while 119/120 (99.2%) and 117/118 (99.2%), respectively, had MenC serum bactericidal assay titers of ≥1:8. All PCV13 recipients and 110/113 (97.3%) of PCV7 recipients had IgG concentrations against fimbrial agglutinogens of ≥2.2 EU/mL; IgG concentrations for the remaining pertussis antigens were ≥5 EU/mL for all participants. Local reactions and systemic events were similar in the PCV13 and PCV7 groups. Conclusions: A 2-, 4-, and 12-month course of PCV13 was immunogenic for all 13 vaccine serotypes and was well tolerated.

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.

Sequential administration of 13-valent pneumococcal conjugate vaccine and 23-valent pneumococcal polysaccharide vaccine in pneumococcal vaccine–naïve adults 60–64 years of age

BACKGROUND Unlike free pneumococcal polysaccharide vaccines (PPSVs), pneumococcal conjugate vaccines (PCVs) induce a T-cell-dependent immune response. The study assessed potential influence of initial 13-valent PCV (PCV13) or 23-valent PPSV (PPSV23) on subsequent vaccine administrations. METHODS We conducted a randomized, modified double-blind study in 720 pneumococcal vaccine-naïve adults 60-64 years of age. Subjects received either PCV13 at year 0 and PCV13 at year 1; PCV13 at year 0 and PPSV23 at year 1; or PPSV23 at year 0 and PCV13 at year 1. Antipneumococcal opsonophagocytic activity (OPA) titers were measured before and 1 month after each vaccination. RESULTS OPA titers following PPSV23 given 1 year after PCV13 (PCV13/PPSV23) (a) were noninferior for the 12 common serotypes and significantly higher for 6 of 12 common serotypes than those following only an initial PPSV23; and (b) were significantly higher for 11 of 12 common serotypes compared with PPSV23 followed by PCV13 (PPSV23/PCV13). In addition, PPSV23 followed 1 year later by PCV13 (PPSV23/PCV13) elicited significantly lower OPA titers than after only an initial dose of PCV13 for all 13 serotypes. Responses after a second vaccination with either PCV13 (PCV13/PCV13) or PPSV23 (PCV13/PPSV23) were noninferior for 9 of 13 and 8 of 12 common serotypes compared with the initial PCV13 dose. CONCLUSION In pneumococcal vaccine-naïve adults 60-64 years of age, an initial PCV13 augmented the antipneumococcal response to subsequent administration of PPSV23 for many of the serotypes in common to both vaccines. In contrast, an initial PPSV23 resulted in a diminished response to subsequent administration of PCV13 for all serotypes. With a relatively short 1-year interval between doses, responses after a second vaccination with PCV13 (PCV13/PCV13) or PPSV23 (PCV13/PPSV23) were noninferior for a majority of serotypes compared with the initial PCV13 dose, probably reflecting the need for a longer interval between vaccine administrations. ClinicalTrials.gov Identifier: NCT00574548.

A randomized, double-blind trial to evaluate immunogenicity and safety of 13-valent pneumococcal conjugate vaccine given concomitantly with trivalent influenza vaccine in adults aged ≥65 years

This randomized, double-blind study evaluated concomitant administration of 13-valent pneumococcal conjugate vaccine (PCV13) and trivalent inactivated influenza vaccine (TIV) in adults aged ≥65 years who were naïve to 23-valent pneumococcal polysaccharide vaccine. Patients (N=1160) were randomized 1:1 to receive PCV13+TIV followed by placebo, or Placebo+TIV followed by PCV13 at 0 and 1 months, with blood draws at 0, 1, and 2 months. Slightly lower pneumococcal serotype-specific anticapsular polysaccharide immunoglobulin G geometric mean concentrations were observed with PCV13+TIV relative to PCV13. Concomitant PCV13+TIV demonstrates acceptable immunogenicity and safety compared with either agent given alone.

A randomized phase I study of the safety and immunogenicity of three ascending dose levels of a 3-antigen Staphylococcus aureus vaccine (SA3Ag) in healthy adults

BACKGROUND Staphylococcus aureus is a common cause of healthcare-acquired morbidity and mortality and increased healthcare resource utilization. A prophylactic vaccine is being developed that may reduce this disease burden. METHODS Volunteers in good general health aged 50-85 (n=312) and 18-24 (n=96) years were randomized to receive a single intramuscular dose of one of three dose levels of a non-adjuvanted, 3-antigen S. aureus vaccine (SA3Ag) or placebo. SA3Ag antigens included capsular polysaccharides 5 and 8 (CP5 and CP8), each conjugated to cross-reactive material 197 (CRM197), and recombinant clumping factor A (ClfA). Safety, tolerability, and immunogenicity were evaluated. RESULTS At day 29 post-vaccination, robust immune responses were observed in both age cohorts at all three SA3Ag dose levels. In the primary analysis population, the 50- to 85-year age stratum, geometric mean-fold-rises in competitive Luminex(®) immunoassay antibody titers from baseline ranged from 29.2 to 83.7 (CP5), 14.1 to 31.0 (CP8), and 37.1 to 42.9 (ClfA), all (P<0.001) exceeding the pre-defined two-fold rise criteria. Similar rises in opsonophagocytic activity assay titers demonstrated functionality of the immune response. Most injection-site reactions were mild in severity and there were no substantial differences (SA3Ag vs. placebo) with regard to systemic or adverse events. CONCLUSIONS In this study of healthy adults aged 50-85 and 18-24 years, SA3Ag elicited a rapid and robust immune response and was well tolerated, with no notable safety concerns.