How Many People Will One Sick Person Infect?

Measles Vaccine

Measles: 1 infected person can infect 12-18 unvaccinated people

• 2 doses total (starting at age 1)
• 97% effective at preventing infection*
• Prevents spread
• Less serious illness

Flu Vaccine

Flu: 1 infected person can infect 1-2 people

• 1 dose yearly (covers 3 strains)
• 40% less serious illness*
• 60% fewer hospitalizations*

RSV Shot

RSV: 1 infected person can infect 3 people

• 1 dose (for infants and ages 65+)
• Less serious illness
• 75% fewer hospitalizations*

Norovirus: 1 infected person can infect 2-7+ people

• No vaccine available
• Many strains exist
• Contagious for 2+ weeks after symptoms are gone

*Based on CDC & NCBI data