An updated guideline for recommended adult immunizations released this week by the Advisory Committee on Immunization Practices (ACIP) and the Centers for Disease Control and Prevention (CDC) features use of a new type of flu vaccine that for the first time allows people with severe egg allergies to receive a protective immunization against influenza.
The 2 types of traditional flu vaccines, the live attenuated vaccine (LAIV) and the inactivated vaccine (IIV), are manufactured by growing influenza virus in chicken eggs. The new flu vaccine, called the recombinant influenza vaccine (RIV), is produced using a genetically engineered insect virus that contains genes encoding a protein involved in triggering immunity against influenza. Cells grown in culture that are infected with this engineered virus produce large quantities of this key protein. (The RIV also offers the promise of faster production of flu vaccine, as described in a news@JAMA post published when the vaccine was approved by the US Food and Drug Administration in January 2013.)
Because RIV does not contain any egg protein, it is safe to give to individuals with egg allergies, even severe ones. People with mild egg allergies (hives only) can receive either RIV or IIV, although additional clinical monitoring after receiving IIV is recommended.
According to the CDC, all individuals 6 months or older should be vaccinated against influenza annually, with rare exceptions.
Another notable change in the new guideline addresses use of the vaccine that protects against Haemophilus influenzae type b (Hib), a bacterium that causes meningitis, pneumonia, and upper respiratory infections. (Despite its misleading name, it does not cause flu.) The Hib vaccine is now recommended for adults who undergo a successful stem cell transplant, a treatment for some hematologic cancers such as leukemia. All infants in the United States are routinely given the Hib vaccine, which should generally provide lifelong protection, except in this select case of adults who should be revaccinated.
Recommendations for other routine vaccinations remained essentially unchanged, aside from some instances of minor changes in wording.
An article published this week in Annals of Internal Medicine further discusses the new guidelines. It notes the generally low levels of vaccine coverage among adults compared with children and encourages clinicians who treat adults to routinely assess vaccination status during clinic visits.