If you have a weak immune system, the number of doses you need depends on your age and how many COVID-19 vaccines you have had in the past.
You may have a weak immune system if:
- You have had or will have an organ or stem cell transplant.
- You have had CAR T-cell therapy (a type of cancer treatment).
- You have kidney disease and need dialysis.
- You have human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS).
- You take certain medicines that weaken your immune system.
If you have a weak immune system:
- You need 3 doses of KP.2+ COVID-19 vaccine if you have never had any COVD-19 vaccine.
- You need 1 dose of KP.2 vaccine at least 3 months after your last dose if you have already had 3 or more doses of a non-KP.2 vaccine.
- You need 1 or 2 doses of KP.2 vaccine to total a 3-dose series if you have already had 1 or 2 doses of a non-KP.2 vaccine.
Studies show that extra doses may give better protection to adolescents and adults with a weak immune system. In babies and children with a weak immune system, extra doses may also give better protection, but research is still happening to learn more.
Research has shown mRNA vaccines provide the best protection for people with a weak immune system. If you have had a stem cell transplant or are getting CAR T-cell therapy, talk to your healthcare provider about when you can get a dose of KP.2 vaccine and how many doses you need.