125285 Apr 2026

At first glance, it’s just a number. In reality, it represents the FDA's authorization of Flublok Quadrivalent, a breakthrough in how we manufacture vaccines. What Makes 125285 Special?

: The recombinant process allows for a more precise match to the flu strains predicted for the season, as it avoids "egg-adaptation" mutations that can sometimes make traditional vaccines less effective. Who is it for? 125285

Most traditional flu vaccines are grown in chicken eggs—a process that has remained largely unchanged for decades. However, the product filed under BLA STN 125285 is different. Manufactured by Protein Sciences Corporation (a Sanofi company), Flublok is a . Here is what that means for you: At first glance, it’s just a number

Clinical reviews associated with STN 125285 show that the vaccine is effective in preventing laboratory-confirmed influenza. Like any vaccine, it can have side effects—most commonly pain at the injection site, headache, or fatigue—but these are typically mild and short-lived. The Bottom Line : The recombinant process allows for a more

While "125285" might look like a random string of numbers, it is actually a significant identifier in the world of public health and pharmaceutical regulation. Most notably, is the Biologics License Application (BLA) Submission Tracking Number (STN) assigned by the FDA for Flublok , a unique type of influenza vaccine.

Here is a blog post exploring why this specific number matters in the fight against the flu.