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.