Timing and Spacing

Janssen COVID-19 Vaccine is administered as a single dose.

COVID-19 vaccines are not interchangeable.

  • In limited, exceptional situations where the first dose of mRNA COVID-19 vaccine was received but the patient is unable to complete the series with the same or different mRNA vaccine (e.g., contraindication) a single dose of Janssen COVID-19 vaccine may be administered at minimum interval of 28 days from mRNA dose*
    • Considered to have received valid, single-dose Janssen vaccination, not mixed vaccination series (mRNA/viral vector)

You may administer COVID-19 vaccines and other vaccines at the same visit, as well as within 14 days of each other. When deciding whether to administer COVID-19 vaccines and other vaccines, you should consider:

  • Whether the patient is behind or at risk of becoming behind on recommended vaccines
  • The patient’s risk of vaccine-preventable diseases (e.g., during an outbreak)
  • The reactogenicity profile of the vaccines

*Consider consultation with an allergist-immunologist to help determine if a patient with a contraindication to an mRNA vaccine can safely receive the Janssen COVID-19 vaccine. Healthcare providers and health departments may also request a consultation from the Clinical Immunization Safety Assessment COVIDvax project. Vaccination of these individuals should only be done in an appropriate setting under the supervision of a healthcare provider experienced in the management of severe allergic reactions.

  • People with a contraindication to mRNA COVID-19 vaccines (including due to a known PEG allergy) have a precaution to Janssen COVID-19 vaccination. People who have previously received an mRNA COVID-19 vaccine dose should wait at least 28 days to receive Janssen COVID-19 Vaccine.
  • People with a contraindication to Janssen COVID-19 Vaccine (including due to a known polysorbate allergy) have a precaution to mRNA COVID-19 vaccination.



Page last reviewed: August 23, 2021