Regarding influenza vaccination, which statement is true?

• A. The intranasal influenza vaccine is a live virus and is contraindicated in pregnancy.
• B. The intranasal influenza vaccine is a live virus but is safe in pregnancy.
• C. The IM influenza vaccine is given in spring.
• D. The IM influenza vaccine can cause influenza infection.

Answer: (A)

Influenza vaccines come in two main forms: an intranasal live attenuated vaccine and an injectable inactivated vaccine. The intranasal product uses a live virus that has been weakened, and because it is a live vaccine, it is not given to pregnant people due to theoretical risk to the fetus. That is why this option is true. In contrast, the injectable influenza vaccine is inactivated, so it cannot cause influenza illness and is considered safe for pregnancy, which is why the other statements about the intranasal vaccine being safe in pregnancy, the timing of the injectable dose in spring, or the injectable vaccine causing influenza infection are incorrect. The flu shot is typically administered in the fall to protect during the flu season.