Vaccine Dose Part 1

Vaccine doses
Staying up to date
Vaccine recommendations and the number of doses you are recommended to get are different depending on your age, the vaccine you first received, and whether you have certain health conditions that weaken your immune system.
You may hear different phrases used to describe vaccine doses or someone's vaccination status. Here's what some of those phrases mean.
• Primary vaccine series: The primary vaccine series refers to the initial number of doses of a particular vaccine that a person needs. It does not include booster shots.
• Booster shots: A booster shot is given when protection from the original vaccination begins to decrease. The additional dose(s) of vaccine can help get protection back up to a higher level.
• Updated or bivalent booster: A booster shot that protects against both the original virus that causes COVID-19 and gives more protection against the Omicron variants (BA.4 and BA.5) that are currently causing most of the cases of COVID-19.
• Up to date: You are up to date with your COVID-19 vaccines when you have received all doses in the primary series and received the most recent booster dose recommended for you, when eligible.
To have the best protection against COVID-19, you should make sure you are up to date on your COVID-19 vaccines. For more information, visit CDC: Stay Up to Date with Your COVID-19 Vaccines Including Boosters.
There are recommendations for people with certain immunocompromising conditions (a weak immune system) to receive an additional dose as part of their primary series. For more information, visit CDC: COVID-19 Vaccines for Moderately to Severely Immunocompromised People.
Your health care provider can provide information on which vaccine you are getting and how many doses you will need.