{"id":240,"date":"2024-02-14T17:30:20","date_gmt":"2024-02-14T17:30:20","guid":{"rendered":"https:\/\/www.merckvaccines.com\/capvaxive\/?page_id=240"},"modified":"2026-04-09T11:12:56","modified_gmt":"2026-04-09T11:12:56","slug":"clinical-studies","status":"publish","type":"page","link":"https:\/\/www.merckvaccines.com\/capvaxive\/clinical-studies\/","title":{"rendered":"Clinical Studies of CAPVAXIVE\u00ae (Pneumococcal 21-valent Conjugate Vaccine)"},"content":{"rendered":"\n\n
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Clinical studies<\/h1><\/div>\n\n\n\n
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CAPVAXIVE was studied in a robust Phase 3 clinical trial program<\/h2><\/div>\n\n\n\n
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In Studies 1-4, CAPVAXIVE was studied in a broad range of >6500 vaccine-na\u00efve and vaccine-experienced adults of varying ages, risk factorsa<\/sup> for pneumococcal disease, races, and\/or ethnic groups.<\/strong><\/p><\/div><\/div>\n\n\n\n
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Across Studies 1-4 for CAPVAXIVE, \u2028~63% of adults included were 50 years of age and older1<\/sup><\/mark><\/strong><\/h2><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n
Study 1: Immunogenicity of CAPVAXIVE in pneumococcal vaccine-na\u00efve adults vs PCV20<\/strong><\/h4><\/summary>
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In individuals 50 years of age and older, <\/mark>CAPVAXIVE<\/strong> was non-inferior to PCV20 for the 10 serotypes common to both vaccines (3, 6A, 7F, 8, 10A, 11A, 12F, 19A, 22F, 33F)<\/strong><\/li>\n\n\n
In individuals 50 years of age and older, CAPVAXIVE<\/strong> was superior to PCV20 for 10 of 11 serotypes included in CAPVAXIVE<\/strong> but not in PCV20 (9N, 15A, 16F, 17, 20A, 23A, 23B, 24F, 31, 35B)<\/strong>\n\n
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Immune responses were observed for serotype 15C in participants 50 years of age and older receiving CAPVAXIVE, but did not meet criteria for statistical significance<\/li>\n\n<\/ul>\n\n<\/li>\n\n\n
64.7% of individuals 50 years and older who received CAPVAXIVE had \u22654-fold in cross-reactive OPA titers for serotype 15B<\/li>\n\n\n
The OPA responses of individuals 18 through 49 years of age to each of 22 S. pneumoniae<\/em> serotypes met the criteria for immunobridging when compared to the OPA responses of individuals 50 through 64 years of age<\/strong><\/li>\n\n<\/ul>\n\n<\/div>\n\n\n
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Study design<\/strong> Study 1 was a randomized double-blind Phase 3 study to assess the immunogenicity of CAPVAXIVE compared to PCV20 in pneumococcal vaccine-na\u00efve individuals. Participants 50 years of age and older (n=2362) were enrolled in cohort 1, and participants 18 through 49 years of age (n=301) were enrolled in cohort 2. For cohort 1, the primary endpoints of the study included serotype specific OPA GMTs 1 month postvaccination and percentage of participants with \u22654-fold rise in serotype specific OPA responses from baseline to 1 month postvaccination. For cohort 2, a conclusion of immunobridging was based on the lower bound of the 2-sided 95% confidence interval for the estimated GMT ratio (18-49 years\/50-64 years) being >0.5.1<\/sup>
There are currently no studies comparing the efficacy of CAPVAXIVE and PCV20.<\/p>\n\n\n
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Study 3: Immunogenicity of CAPVAXIVE in pneumococcal vaccine-experienced adults<\/strong><\/h4><\/summary>
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In individuals who previously received PPSV23, CAPVAXIVE elicited OPA responses<\/strong> that were comparable to PCV15 for the 6 common serotypes (3, 6A, 7F, 19A, 22F, 33F), and higher OPA responses for the 15 unique serotypes (8, 9N, 10A, 11A, 12F, 15A, 15C, 16F, 17F, 20A, 23A, 23B, 24F, 31, 35B) and serotype 15B<\/strong><\/li>\n\n\n
In individuals who previously received PCV13, CAPVAXIVE elicited OPA responses<\/strong> comparable to PPSV23 for the 12 common serotypes (3, 7F, 8, 9N, 10A, 11A, 12F, 17F, 19A, 20A, 22F, 33F) and serotype 15B, and higher OPA responses for the 9 unique serotypes (6A, 15A, 15C, 16F, 23A, 23B, 24F, 31, 35B)<\/strong><\/li>\n\n\n
OPA responses to CAPVAXIVE were similar across the 3 cohorts of participants who previously received one or more pneumococcal vaccines<\/li>\n\n<\/ul>\n\n<\/div>\n\n\n
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Study design <\/strong>Study 3 was a descriptive Phase 3 study that enrolled vaccine-experienced individuals 50 years and older who received a pneumococcal vaccine at least 1 year prior to enrollment (n=717). Study 3 included three cohorts. For cohort 1, individuals who previously received PPSV23 were randomized to receive CAPVAXIVE (n=231) or PCV15 (n=119). For cohort 2, individuals who previously received PCV13 were randomized to receive either CAPVAXIVE (n=176) or PPSV23 (n=85). For cohort 3, individuals who received other prior pneumococcal vaccines (PCV13 + PPSV23, PCV15 + PPSV23, PPSV23 + PCV13 or PCV15) were allocated to receive CAPVAXIVE (n=106). In each of the 3 cohorts, serotype-specific OPA GMTs and the proportion of individuals with \u22654-fold rise in OPA responses from baseline to 1-month postvaccination were assessed.<\/p>\n\n\n
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Study 5: Immunogenicity of CAPVAXIVE in adults living with HIV infection<\/strong><\/h4><\/summary>
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In individuals 18 years of age and older living with HIV infection who received CAPVAXIVE, OPA GMTs at 1-month postvaccination in participants were numerically similar to those in participants who received PCV15 + PPSV23 for the 13 shared serotypes (3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15B, 17F, 19A, 22F, 33F)<\/strong><\/li>\n\n\n
In individuals 18 years of age and older living with HIV infection who received CAPVAXIVE, OPA GMTs at 1-month postvaccination were numerically higher for the 8 serotypes unique to CAPVAXIVE compared with PCV15 + PPSV23 (15A, 15C, 16F, 23A, 23B, 24F, 31, 35B)<\/strong><\/li>\n\n\n
Following vaccination with CAPVAXIVE, the most frequently reported (>10%) solicited adverse reactions were injection-site pain (48.4%), fatigue (21.3%), and headache (16.8%). No serious adverse events were considered to be related to CAPVAXIVE<\/strong><\/li>\n\n<\/ul>\n\n<\/div>\n\n\n
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Study design <\/strong>Study 5 was a double-blind descriptive study that enrolled individuals 18 years of age and older living with HIV, with CD4+ Tcells\/\u00b5L \u226550 and plasma HIV RNA <50,000 copies\/mL, with or without a history of prior pneumococcal vaccination (n=313). Participants were randomized in a 1:1 ratio to receive either CAPVAXIVE followed by placebo 8 weeks later, or PCV15 followed by PPSV23 8 weeks later. OPA GMTs were assessed 1-month postvaccination.
The effectiveness of CAPVAXIVE in individuals with HIV has not been established.<\/p>\n\n\n
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Study 6: Immunogenicity of CAPVAXIVE in adults at increased risk of pneumococcal disease due to certain medical conditions<\/strong><\/h4><\/summary>
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In high-risk individuals 18 through 64 years of age who received CAPVAXIVE, OPA GMTs at 1-month postvaccination were numerically similar to those who received PCV15 + PPSV23 for the 13 shared serotypes (3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15B, 17F, 19A, 22F, 33F)<\/strong><\/li>\n\n\n
In high-risk individuals 18 through 64 years of age who received CAPVAXIVE, OPA GMTs at 1-month postvaccination were numerically higher for the 8 serotypes unique to CAPVAXIVE compared with PCV15 + PPSV23 (15A, 15C, 16F, 23A, 23B, 24F, 31, 35B)<\/strong><\/li>\n\n<\/ul>\n\n<\/div>\n\n\n
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Study design <\/strong>Study 6 was a double-blind descriptive study that enrolled individuals 18\u201364 years of age (n=518) with increased risk of pneumococcal disease due to one or more prespecified medical conditions (diabetes mellitus, chronic heart disease, chronic kidney disease, chronic liver disease, chronic lung disease). 82 (15.9%) participants had \u22652 increased risk conditions. Participants were randomized in a 3:1 ratio to receive either CAPVAXIVE followed by placebo 8 weeks later, or PCV15 followed by PPSV23 8 weeks later. OPA GMTs were assessed 1-month postvaccination.<\/p>\n\n<\/div><\/details><\/div>\n\n\n\n
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CAPVAXIVE can be coadministered with the influenza vaccine<\/h2><\/div>\n\n\n\n
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Study 4: CAPVAXIVE with influenza vaccine coadministration<\/strong><\/h4><\/summary>
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The OPA responses to CAPVAXIVE administered concomitantly with quadrivalent influenza vaccine were non-inferior to the OPA responses to CAPVAXIVE administered sequentially after influenza vaccine for 20 of 21 serotypes contained in CAPVAXIVE (serotype 23B did not meet non-inferiority criterion). The OPA response to serotype 15B was not assessed for non-inferiority. Influenza vaccine administered concomitantly with CAPVAXIVE was non-inferior to influenza vaccine administered alone as assessed by influenza strain-specific HAI responses for 3 of 4 influenza strains (strain A\/H3N2 did not meet non-inferiority criterion).
Study design<\/strong> Study 4 was a double-blind study that enrolled 1080 individuals 50 years of age and older, with or without a history of prior pneumococcal vaccination, who were randomized in a 1:1 ratio. One vaccination group received CAPVAXIVE and the quadrivalent influenza vaccine concomitantly, followed by placebo 30 days later (concomitant group). A second vaccination group received the influenza vaccine and placebo concomitantly followed by CAPVAXIVE 30 days later (sequential group). Primary endpoints of the study were CAPVAXIVE serotype-specific OPA GMT (concomitant group\/sequential group) and influenza strain-specific HAI GMTs at 1 month postvaccination (concomitant group\/sequential group).<\/p>\n\n\n
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