Why Nasal Vaccines?

Traditional injected vaccines train your immune system to fight infections in your bloodstream. But many respiratory viruses, like COVID-19 and flu, infect through your nose and throat first. Nasal vaccines aim to stop infections where they start.

How They Create Immunity

Mucosal Immunity

Your nose and throat are lined with mucous membranes—your body's first line of defense. Nasal vaccines stimulate:

• IgA antibodies: Found in mucus, these neutralize pathogens on contact
• Resident immune cells: T-cells that live in nasal tissue
• Local memory: Faster response to future infections

Sterilizing Immunity

The goal is "sterilizing immunity"—preventing infection entirely, not just reducing symptoms. This could also reduce transmission to others.

Current Nasal Vaccines

• FluMist: Live attenuated flu vaccine (approved)
• COVID-19 nasal vaccines: In development/trials in multiple countries

Advantages Over Injections

• No needles (better for needle-phobic people)
• Easier to administer (no trained medical staff needed)
• Targets infection site directly
• May prevent transmission, not just disease
• Easier storage and distribution potential

Challenges

• Harder to get consistent dosing
• Pre-existing immunity in nasal passages may interfere
• Some people have nasal conditions affecting delivery