Table of contents
- Overview of the trial
- Who the study is for
- Study phase and design
- What the trial measures
- Study intervention and comparators
- How to read the results
Overview of the trial
The trial NCT05823974 studied GSKVX000000040033 in a vaccine against influenza for healthy younger and older adults.[1] The main goals were to find and confirm the dose and to assess safety, reactogenicity, and immune response.[1]
This was an interventional study, which means participants received a study intervention and were then observed for results.[1] The study is listed as completed and included 1,272 participants.[1]
Who the study is for
The trial focused on healthy volunteers and specifically included healthy younger and older adults.[1] In simple terms, this means people without the illness being treated were enrolled so researchers could study the vaccine in a prevention setting.[1]
The condition studied was prevention of influenza infection, not treatment of active flu illness.[1]
Study phase and design
NCT05823974 was a Phase 1/2 study.[1] Early-phase studies usually look first at safety, then also begin to measure whether the body makes an immune response.[1]
The brief summary says the study aimed to evaluate the safety and reactogenicity profile of the investigational intervention and the humoral immune response it caused.[1] Humoral immune response means the response measured in the blood, usually through antibodies.[1]
What the trial measures
The trial measured several types of outcomes related to safety.[1] These included solicited administration site events from Day 1 to Day 7, which are expected reactions where the injection was given, and solicited systemic events, which are reactions affecting the whole body.[1]
It also measured unsolicited adverse events from Day 1 to Day 28, serious adverse events from Day 1 to Day 183, adverse events of special interest from Day 1 to Day 183, and medically attended events from Day 1 to Day 183.[1] These are different ways to track unwanted medical problems during and after the study.[1]
For Phase 1 only, the study also checked whether lab values changed from non-clinically significant to clinically significant abnormal values after dosing, using blood tests for hematology and clinical chemistry.[1] Hematology means blood cell testing, and clinical chemistry means tests of substances in the blood that help show how the body is working.[1]
The immune response outcomes were centered on antibody measurements for antigen 1 and antigen 2 at Day 29 and the change from Day 1 to Day 29.[1] The study measured geometric mean titer, geometric mean increase, seroconversion rate, and whether antibody levels reached or stayed above a cut-off value.[1]
Study intervention and comparators
The intervention list shows GSKVX000000040033 given by intramuscular injection, meaning into a muscle.[1] The study also included other vaccine codes and comparator products, including Alpharix-Tetra and EFLUELDA, both listed as influenza vaccines.[1]
Because the intervention list contains multiple vaccine code combinations, the study appears to compare different study formulations and control vaccines across groups.[1] The source data do not provide the full group-by-group layout, so the safest summary is that GSKVX000000040033 was one of several influenza vaccine-related study interventions.[1]
How to read the results
When a trial looks at safety, it is checking whether people have reactions after vaccination and how often they happen.[1] When it looks at immune response, it is checking whether the body makes antibodies after vaccination and how strong that response is.[1]
For this study, the most important patient-friendly idea is that researchers wanted to learn whether GSKVX000000040033 could be used in an influenza vaccine program for healthy adults, and whether it produced the expected immune response while being acceptably safe.[1]



