NHSN Definitions for Primary Vaccine Series, Booster, Additional Dose

• Primary Vaccine Series
  • Completing a primary vaccine series means receiving:
  • A 2 – dose series of an mRNA COVID-19 vaccine (Pfizer-BioNTech and Moderna), OR
  • A single does of Janssen COIVD-19 vaccine
• Booster Dose
  • A booster dose is another dose of vaccine administered after receiving a primary vaccine series to enhance or restore protection which might have subsided over time
• Additional Dose
  • An additional dose is another dose of vaccine administered to people who were less likely to mount a protective immune response after initial vaccination. People who are moderately or severely immunocompromised should receive an additional dose.
• Difference between Booster and Additional Dose
  • The dose counts as a booster: If no further details are provided, count these doses as boosters (rather than additional doses) for NHSN
  • The dose counts as an additional: only if there is specific documentation indicating additional doses were administered due to the individual having a moderately to severely immunocompromised condition.