Ask the Experts: All Questions

Ask the Experts is one of our most popular destinations for healthcare professionals. Our experts provide clear, easy-to-understand answers to commonly asked questions about vaccines and their use.

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Results (10)

This is not true. Pregnant healthcare personnel may administer any vaccine except the ACAM2000 smallpox vaccine.

Last reviewed: December 28, 2022

An excellent resource for vaccine contraindications and precautions is the CDC online resource, “General Best Practice Guidelines for Immunization”. A table in the Contraindications and Precautions chapter has a listing for all routine vaccines in the United States available at www.cdc.gov/vaccines/hcp/acip-recs/general-recs/contraindications.html. In addition, a table of contraindications and precautions is provided in the appendix of current CDC recommended adult and child/adolescent immunization schedules, available at www.cdc.gov/vaccines/hcp/imz-schedules.

Last reviewed: February 19, 2024

This is not true. Pregnant healthcare personnel may administer any vaccine except the live, replication-competent smallpox vaccine (ACAM2000, Emergent Biosolutions).

Last reviewed: August 29, 2022

With the exception of two vaccines used to prevent smallpox or mpox (previously known as monkeypox), there is no recommendation to wait until a vaccine reaches room temperature before administration. The vaccine should be administered as soon as it is prepared.

The live smallpox (vaccinia) vaccine, ACAM2000 (Emergent Product Development Gaithersburg, Inc.) and the non-replicating, live smallpox and mpox vaccine, Jynneos (Bavarian Nordic) should be brought to room temperature before use, according to the package inserts for these two products.

Last reviewed: December 28, 2022

Having a pregnant person in a household, including the child’s mother, is not a contraindication to administration of any routinely recommended vaccine. Pregnant people should not have close contact with anyone who has recently (within the last 28 days) received the live, replication-competent smallpox vaccine (ACAM2000, Emergent Biosolutions).

Last reviewed: August 29, 2022

All vaccines except the live, replication-competent smallpox vaccine (ACAM2000, Emergent Biosolutions) and yellow fever vaccine may be given to people who are breastfeeding.

ACAM2000 is contraindicated due to the theoretical risk of contact transmission of the vaccine virus from mother to child.

The only yellow fever (YF) vaccine licensed in the United States (YF-Vax, Sanofi) is contraindicated in people who are breastfeeding infants younger than 9 months of age. There have been three case reports of YF vaccine-associated encephalitis in infants under one month of age who were being exclusively breastfed at the time the mother received YF vaccine. ACIP currently recommends that people who are breastfeeding should be advised to postpone travel to YF endemic or epidemic regions; however, if travel cannot be avoided or postponed, the breastfeeding parent should receive YF vaccine. Although there are no data, some experts recommend that breastfeeding people who receive YF vaccine should temporarily suspend breastfeeding, pump, and discard pumped milk for at least 2 weeks after vaccination before resuming breastfeeding.

Last reviewed: August 29, 2022

A pregnant person may administer any vaccine except live, replication-competent smallpox vaccine (ACAM2000, Emergent Biosolutions).

Last reviewed: August 29, 2022

Yes. Household contacts and other close contacts of people who are immunocompromised (due to a disease, or treatment for a disease) should receive all routinely recommended vaccines, with the exception of smallpox vaccine. The live MMR, varicella, and rotavirus vaccines should be administered to susceptible household contacts and other close contacts of immunocompromised patients when indicated. MMR vaccine viruses are not transmitted to contacts, and transmission of vaccine strain varicella-zoster virus is rare. No specific precautions are needed unless the varicella vaccine recipient has a rash after vaccination, in which case direct contact with susceptible immunocompromised household contacts should be avoided until the rash resolves. All members of the household should wash their hands after changing the diaper of an infant who received rotavirus vaccine. This minimizes rotavirus transmission, as shedding may occur up to one month after the last dose.

Household and other close contacts of immunocompromised persons should receive annual influenza vaccination. Introduction of low levels of vaccine viruses into the environment likely is unavoidable when administering quadrivalent live attenuated influenza vaccine (LAIV4; Flumist, Medimmune). LAIV4 vaccine viruses are cold-adapted so they can replicate in the nose and generate an immune response without entering the lungs (that is, they are temperature sensitive and replicate poorly at core body temperatures). No instances have been reported of illness caused by attenuated vaccine virus infections among healthcare providers or immunocompromised patients. LAIV may be administered to healthy nonpregnant household and other close contacts of immunocompromised people unless the immunocompromised person is hospitalized in a protective environment, typically defined as a specialized patient-care area with a positive airflow relative to the corridor, high-efficiency particulate air filtration, and frequent air changes. A person who is administered LAIV4 should not have contact with an immunocompromised person in this type of protective environment for 7 days after administration.

Last reviewed: August 29, 2022

Yes, COVID-19 vaccines and other routine vaccines, including influenza and RSV vaccines, may be coadministered on the same day, given in different syringes and at different anatomical sites. COVID-19 vaccines may also be given at any interval before or after any other vaccination.

Of note, there is no required minimum interval between receiving a dose of any COVID-19 vaccine and an orthopoxvirus vaccine, either Jynneos or ACAM2000 vaccine (e.g., for mpox prevention), regardless of which vaccine is administered first. However, use of Jynneos vaccine should be prioritized over ACAM2000 when co-administering a COVID-19 vaccine and an orthopoxvirus vaccine.

People, particularly adolescent or young adult males, who are recommended to be vaccinated against both mpox and COVID-19 might consider waiting 4 weeks between vaccines. This is because of the observed risk for myocarditis and pericarditis after receipt of ACAM2000 orthopoxvirus vaccine and COVID-19 vaccines, and the hypothetical risk for myocarditis and pericarditis after Jynneos vaccine. However, if a patient’s risk for mpox or severe disease due to COVID-19 is increased, administration of mpox and COVID-19 vaccines should not be delayed.

Additional information about simultaneous administration with other vaccines is available from CDC: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#age-transitions.

Last reviewed: August 31, 2024

Yes. Mothers who have never received Tdap and who did not receive it during pregnancy should receive it immediately postpartum or as soon as possible thereafter. Breastfeeding does not decrease the immune response to routine childhood vaccines and is not a contraindication for any vaccine except smallpox. Breastfeeding is a precaution for yellow fever vaccine and the vaccine can be given for travel when indicated.

Last reviewed: March 31, 2022

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