Measuring Viral Vectors: Why Particles ≠ Infectious Units

When people ask “how much vector do we have?” the answer isn’t simple. Scientists measure both the total number of particles and how many of those are actually infectious - and the two numbers can be very different.

Section 1: The Key Measurements:

• Particle count (ELISA)

• Particle count (genomes)

• Infecitous units (how we measure it, why it’s trickier)

Section 2: Why they don’t match

• Explain inefficiencies in production. Analogy: imagine making 100 cookies, but only 60 are edible, the rest are burned or broken.

Section 3: Why it matters

• Implications for dosing, safety, and regulatory approval

• Reinforce point: good analytics = good decisions - each subsection has a small illustration/icon

Key takeaway box, 2-3 bullets

• Not all viral vector particles are infectious

• Understanding the difference is critical for dosing and quality control

• Analytics provide the context that makes these numbers meaningful

Call to Action: button to download this explainer as a PDF