by David J. Weber, MD, MPH
This summary is based on the just released CDC/ACIP statement “Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States,
2016–17 Influenza Season (http://www.cdc.gov/mmwr/volumes/65/rr/rr6505a1.htm).
Influenza viruses typically circulate widely in the United States annually, from the late Fall through early Spring. Although most persons who become infected with influenza viruses will recover without sequelae, influenza can cause serious illness and death, particularly among older adults, very young children, pregnant women, and those with chronic medical conditions. During 31 seasons from the 1976–77 through the 2006–07 season, estimated influenza-associated deaths ranged from approximately 3,300 to 49,000 annually. Annual influenza vaccination is the primary means of preventing influenza and its complications. A variety of different types of influenza vaccine are available. Routine annual influenza vaccination for all persons aged ≥6 months who do not have contraindications has been recommended by CDC and ACIP since 2010.
Primary changes and updates in recommendations are included in the CDC/ACIP statement. Routine annual influenza vaccination of all persons aged ≥6 months without contraindications continues to be recommended. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended product is otherwise appropriate. Updated information and guidance in this document includes the following:
- In light of low effectiveness against influenza A(H1N1)pdm09 in the United States during the 2013–14 and 2015–16 seasons, for the 2016–17 season, ACIP makes the interim recommendation that LAIV4 should not be used.
- 2016–17 U.S. trivalent influenza vaccines will contain an A/California/7/2009 (H1N1)–like virus, an A/Hong Kong/4801/2014 (H3N2)–like virus and a B/Brisbane/60/2008–like virus (Victoria lineage). Quadrivalent vaccines will include an additional vaccine virus strain, a B/Phuket/3073/2013–like virus (Yamagata lineage).
- Recent new vaccine licensed include:
- An MF59-adjuvanted trivalent inactivated influenza vaccine (aIIV3), Fluad (Seqirus, Holly Springs, North Carolina), was licensed by FDA in November 2015 for persons aged ≥65 years. aIIV3 is an acceptable alternative to other vaccines licensed for persons in this age group.
- A quadrivalent formulation of Flucelvax (cell culture-based inactivated influenza vaccine [ccIIV4], Seqirus, Holly Springs, North Carolina) was licensed by FDA in May 2016, for persons aged ≥4 years. ccIIV4 is an acceptable alternative to other vaccines licensed for persons in this age group.
- Recommendations for influenza vaccination of persons with egg allergy have been modified:
- Removal of the recommendation that egg-allergic recipients should be observed for 30 minutes postvaccination for signs and symptoms of an allergic reaction. Providers should consider observing all patients for 15 minutes after vaccination to decrease the risk for injury should they experience syncope, per the ACIP General Recommendations on Immunization.
- A recommendation that persons with a history of severe allergic reaction to egg (i.e., any symptom other than hives) should be vaccinated in an inpatient or outpatient medical setting (including but not necessarily limited to hospitals, clinics, health departments, and physician offices), under the supervision of a health care provider who is able to recognize and manage severe allergic conditions.
Methods of increasing healthcare personnel (HCP) coverage (goal is 100% immunized) include: 1) requiring immunization as a condition of employment (except for medical contra-indications per CDC and religious objections); 2) providing vaccine at no cost to HCP; 3) providing vaccine at times and locations convenient to HCP; 4) strong leadership support; 5) mobile carts (i.e., carts that go to the HCP location of work);and, 6) choice of vaccines (i.e., standard IM and ID).
Table 1. Current terminology for Influenza Vaccines
- Inactivated influenza vaccines are abbreviated IIV. For the 2016–17 season, IIVs as a class will include:
- Egg-based, unadjuvanted, and adjuvanted trivalent influenza vaccines (IIV3s); and
- Egg-based or cell culture-based unadjuvanted quadrivalent influenza vaccines (IIV4s).
- RIV refers to recombinant hemagglutinin influenza vaccine, available as a trivalent formulation (RIV3) for the 2016–17 season.
- LAIV refers to live-attenuated influenza vaccine, available as a quadrivalent formulation (LAIV4) since the 2013–14 season.
- IIV, RIV, and LAIV denote vaccine categories; numeric suffix specifies the number of HA antigens in the vaccine.
- When necessary to refer specifically to cell culture-based vaccine, the prefix cc is used (e.g., ccIIV4).
- When necessary to refer specifically to adjuvanted vaccine, the prefix a is used (e.g., aIIV3).