August 11, 2021 03:51 Updated Follow The CDC’s Advisory Committee on Immunization Practices (ACIP) does not recommend mixing doses at this time. Related articles I got the Johnson & Johnson vaccine. Should I also get a dose of an mRNA to protect against the variants? I do not have a doctor’s order but would like to get a different vaccine than I got the first time. I am immunocompromised and want to make sure the vaccine was effective. Can I get an appointment at a vaccine clinic? I have a doctor’s order for a different type of vaccine because the first one wasn’t effective. Can I get an appointment at a vaccine clinic? Should an immunocompromised person seek out antibody testing to ensure the vaccine worked? What are the Pfizer vaccine ingredients?