DOI: 10.3886/e243698v1
title: COVID-19 Primary Series Completion, Booster Dose Eligibility, and Booster Dose Receipt by Age, United States

description: This site provides historical data beginning June 22, 2022, for the visualization presented on COVID-19 Data Tracker’s “Vaccinations in the United States” site titled “Primary Series Completion, Booster Dose Eligibility, and Booster Dose Receipt by Age, United States”.

Fully Vaccinated / Completed Primary Series:
For surveillance purposes, COVID Data Tracker counts people as being "fully vaccinated" or as having "completed a primary series" if they received two doses on different days (regardless of time interval) of the two-dose mRNA series or received one dose of a single-dose vaccine. When the vaccine manufacturer is not reported, the recipient is considered fully vaccinated with two doses.
First Booster Dose: 
For surveillance purposes, the count and percentage of people who received a first booster dose includes anyone who is fully vaccinated and has received another dose of COVID-19 vaccine since August 13, 2021. This includes people who received a first booster dose and people who received an additional primary series dose as this metric does not distinguish if the recipient is  immunocompromised and received an additional dose.
First booster dose eligibility:
CDC counts people as being " eligible for a first booster dose" if it has been at least 5 months since completion of a Pfizer-BioNTech or Moderna primary series or at least 2 months since receipt of a Janssen (Johnson & Johnson) singe-dose vaccine.

Second Booster Dose:
For surveillance purposes, the count and percentage of people who received a second booster dose includes anyone who is fully vaccinated and has received two subsequent doses of COVID-19 vaccine since August 13, 2021. This includes people who received two booster doses and people who received one additional dose and one booster dose. 
The count of people who received a second booster dose and the percentage of people with a first booster who received a second booster dose does not account for whether a person is immunocompromised or time interval since first booster dose.
Second booster dose eligibility:
CDC counts people as being  "eligible for a second booster dose"  if it has been at least 4 months since receiving a first booster dose.
Limitations to counting people with a second booster dose:

Due to the aggregate vaccination record reporting method used by Idaho for its residents under the age of 18 years and by Texas for all its residents, CDC counts all 4th doses received by these populations as a second booster dose. This includes immunocompromised individuals who received a three-dose primary series and only one booster dose. This limitation may lead to an undercount of people who received the single-dose J&J/Janssen vaccine as their primary series and two booster doses.


Data represents all vaccine partners including jurisdictional partner clinics, retail pharmacies, long-term care facilities, dialysis centers, Federal Emergency Management Agency and Health Resources and Services Administration partner sites, and federal entity facilities.
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