TOPLINE:

In adults living with HIV, the 21-valent pneumococcal conjugate vaccine (PCV) V116 was well tolerated and effective against all 21 target serotypes. The immune responses were comparable to those elicited by the standard regimen of the 15-valent PCV (PCV15) followed by the 23-valent pneumococcal polysaccharide vaccine (PPSV23).

METHODOLOGY:

• Adults living with HIV face a high risk for invasive pneumococcal disease, largely due to serotypes not covered by existing vaccines. V116 is an adult-specific, 21-valent PCV that includes eight unique serotypes absent from other PCVs, potentially broadening protection.
• Researchers conducted a two-part multicenter phase 3 trial to evaluate the safety, tolerability, and immunogenicity of the adult-specific 21-valent PCV, V116, in adults living with HIV.
• They enrolled 313 patients (mean age, 45 years; 71% men; 48% White individuals) who had CD4 counts ≥ 50 cells/μL, plasma HIV RNA load < 50,000 copies/mL, and received combination antiretroviral therapy for ≥ 6 weeks.
• In the first part of the trial, patients were randomly assigned to receive either V116 followed by placebo after 8 weeks or the current standard of care, PCV15 followed by PPSV23 after 8 weeks. In the second part, patients who received V116 were given PCV15.
• The primary outcome of the first part was the serotype-specific opsonophagocytic geometric mean titers (GMTs) 30 days post-vaccination for the 13 serotypes shared with PCV15 plus PPSV23 and the eight serotypes unique to V116, whereas the second part measured immune responses to PCV15 30 days after vaccination.

TAKEAWAY:

• V116 triggered immune responses for all 21 serotypes, with responses for the 13 shared serotypes comparable to those elicited by PCV15 plus PPSV23 at week 12 and increased responses for the eight serotypes unique to V116. Serotype-specific geometric mean concentrations of IgG at day 30 were also consistent.
• V116 was immunogenic across all prespecified subgroups — age, CD4 count, sex, prior pneumococcal vaccination, race, ethnicity, and time since last vaccine. Opsonophagocytic activity GMTs were higher in participants aged 18-49 years and those with CD4 ≥ 500 cells/µL.
• When administered after V116, PCV15 showed immunogenicity for all 15 included serotypes 30 days post-vaccination.
• Fewer participants in the V116 plus placebo group experienced at least one adverse event than those in the PCV15 plus PPSV23 group (72% vs 91%), with no vaccine-related serious adverse events or deaths.

IN PRACTICE:

“Adults at high risk for pneumococcal disease due to underlying comorbid conditions, such as HIV, might benefit from receiving V116. The serotypes in V116, of which eight are unique, are expected to provide broader protection against pneumococcal disease than currently licensed vaccines,” the authors wrote.

SOURCE:

This study was led by Jayani Pathirana, PhD, MSD Switzerland, Zurich, Switzerland. It was published online on September 12, 2025, in The Lancet HIV.

LIMITATIONS:

This study was limited by a small sample size. The descriptive nature of the trial precluded hypothesis testing to compare safety and immunogenicity profiles. Additionally, generalizability was limited because most participants had CD4 counts ≥ 500 cells/µL and undetectable viral loads.

DISCLOSURES:

This study was funded by MSD. Seven authors reported being employed by the funder or owning stock or holding stock options in the company. Several other authors reported receiving consulting fees, honoraria, grants, or institutional funding and advisory board support from multiple companies and agencies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.