Table of Contents
- What is CX-039776?
- How Does CX-039776 Work?
- Clinical Trial Overview
- Who Can Participate in the Study?
- Safety and Effectiveness Measures
- Potential Benefits of CX-039776
What is CX-039776?
CX-039776 is an investigational mRNA vaccine being developed to prevent influenza (flu) in adults aged 50 and older[1]. It is part of a new vaccine called mRNA-1010, which also includes two other components: CX-044933 and CX-037231. This vaccine is being studied as a potential alternative to currently licensed seasonal flu vaccines.
How Does CX-039776 Work?
As an mRNA vaccine, CX-039776 works differently from traditional flu vaccines. Instead of using weakened or inactivated flu viruses, it uses genetic material (mRNA) to instruct your body’s cells to produce proteins that resemble parts of the flu virus. This helps your immune system recognize and fight against real flu viruses if you’re exposed to them[1].
Clinical Trial Overview
A large-scale clinical trial (Phase 3) is being conducted to evaluate the safety and effectiveness of mRNA-1010, which includes CX-039776. This study compares mRNA-1010 to a licensed seasonal influenza vaccine in adults aged 50 and older[1]. The main goals of this study are:
- To assess the safety and side effects of mRNA-1010
- To determine how well mRNA-1010 protects against flu-like illness caused by any influenza A or B strains compared to the licensed vaccine
- To evaluate the immune response generated by mRNA-1010 compared to the licensed vaccine
Who Can Participate in the Study?
The study is designed for adults aged 50 and older. However, there are specific criteria for who can and cannot participate. Some key points include:
- Participants must be capable of giving informed consent
- Women who can become pregnant must use acceptable contraception methods
- People with certain medical conditions or recent vaccinations may be excluded
It’s important to note that the study excludes individuals who have recently had the flu, received flu vaccines, or been in close contact with someone with confirmed flu[1].
Safety and Effectiveness Measures
The study will closely monitor participants for any side effects or adverse reactions. This includes:
- Local and systemic reactions: These are immediate responses at the injection site or throughout the body, such as pain, redness, fever, or fatigue.
- Unsolicited adverse events: Any unexpected health issues that occur after vaccination.
- Serious adverse events: Any severe health problems that may or may not be related to the vaccine.
To measure effectiveness, the study will track how many participants develop flu-like illness and confirm flu infections using laboratory tests. The researchers will also measure the immune response by looking at antibody levels in participants’ blood[1].
Potential Benefits of CX-039776
While the full benefits of CX-039776 are still being studied, mRNA vaccines like this one have several potential advantages:
- They can be developed and manufactured more quickly than traditional vaccines, which could be crucial for responding to new flu strains.
- mRNA vaccines don’t contain live viruses, reducing certain risks associated with some traditional vaccines.
- They may provide broader protection against multiple flu strains.
However, it’s important to remember that these potential benefits are still being evaluated in the ongoing clinical trial[1].



